Forem: Tunde Oretade

Creating a Virtual Network with Two Virtual Machines that can ping each other.

Tunde Oretade — Fri, 12 Jul 2024 21:46:36 +0000

INTRODUCTION

Today I will be writing about how to create a Virtual Network with Two Virtual Machines that can ping each other. This process involves setting up a virtual environment where multiple virtual machines (VMs) can communicate seamlessly, mimicking a real-world network setup.
In this article, I will walk through the steps necessary to create a virtual network and configure two virtual machines to ensure they can successfully ping each other, demonstrating effective connectivity and interaction within the virtualized environment.

STEP 1: CREATE A VIRTUAL NETWORK & A SUBNET

From the Azure Portal home page, at the top left corner of the page, click the hamburger (menu) button.
select virtual networks from the sidebar.
Click +create at the top of the create network page.
At the Basics tab, under Project details and at the Resource group label, click create new link. Provide a name for the resource group and click Ok.
Under the instance details label, provide a name for the network and select a suitable Region.
Click the IP Addresses tab at the top of the page, to add a subnet.
At the dropdown menu displayed above the address space box on the
displayed page, check that the dropdown is set to Add IPv4 address
space
In the address space box, change Subnet address range to
10.1.0.0/16 (This is usually the default IP address so you may not
need to change it in this instance).
locate the pen icon at the bottom corner, in the address space box (next
to the garbage can icon). Click on this icon to edit the default
Subnet name/add a subnet.
Leave the Subnet Purpose at Default.
Change Subnet name to vnet1-subnet.
Also, change Subnet address range to 10.1.0.0/24 using the
size label. Leave all other settings as their defaults.
Click Add to close the Add a Subnet pane. This
completes the creation of the subnet.
Click Review + create to run validation.
When you see the notification that Validation passed, click the
Create button to deploy the Virtual Network.

STEP 2: CREATE TWO VIRTUAL MACHINES IN THE NETWORK (VIRTUAL NETWORK)

After the virtual network deployment is complete click Go to resource.
Click the hamburger menu button (top left of the page) and select virtual machines.
Click + Create icon and then select Virtual machine.
On the Basics tab, at the Project details and at the Resource group label, select the resource group created earlier from the drop-down list of resource groups. This is the deployment ID.
At the Instance details heading and the Virtual machine name click the input box and name the virtual machine as vm1.
At the Region label select a suitable region. In this case, I selected East US.
Set Availability options to No infrastructure redundancy required
Set Security type to Standard.
At the Image label, select windows server 2019 Datacenter - Gen 2.
set vm architecture to x64.
Next, untick Run with Azure spot discount
Then, set size to Standard_Dc4ads_cc_v5... At times the size required may not be listed. If this happens select the see all sizes link. This will take you to another page to select a VM size.
Do not Enable Hibernation. In my case Hibernation isn't supported for my VM size.
At the Administrator account heading, select a Username and Password. Also confirm password by re-typing the password in the input box at the confirm password label. (These are the details that will be required to access the Virtual machines when it is in operation.)
At the Inbound port rules heading leave the Public inbound ports set at the default.
set select inbound ports to default which is RDP(3389).
Do not tick the Licensing section as well.
Click the networking tab at the top of the page. Make sure that vm1 is placed on the Vnet1-subnet virtual network.
Click Review + create to validate the configurations.
When you see the notification that Validation passed, click the Create button to deploy the first Virtual Machine.
Next, create the Second virtual machine in the same virtual network following the steps listed under this heading. Make sure the second Virtual machine has a different name and a different IP address for networking.

STEP 3: TEST THE CONNECTIONS

to view the deployed virtual machines, search for virtual machines in the search bar at the top of the page.
At the listing, click vm1 to open it.
at vm1 overview page, you will notice that the status is Running. Click the IP address link at the Public IP address label to increase the timeout settings. You can check here to see how it is done. This is one of the industry's best practices. However, I didn’t increase the Timeout for my virtual machine in this article.
Still at the vm1 overview page, click Connect at the top of the page.
Select Download RDP file.
Open the downloaded RDP file for vm1.
When prompted, click connect.
Provide the credentials created for administrator account while creating vm1 virtual machine. Provide the password and click ok.
You may receive a certificate warning prompt. Click continue to create the connection to your deployed virtual machine.
Follow the same process listed above to also open vm2.
Now that both virtual machines are open, go to vm1 interface. Click on the search button icon at the bottom of the page.
Type firewall.
Select windows defender firewall in the search results.
Click turn Windows Defender Firewall on or off
Modify the firewall setting by clicking turn off windows defender firewall for Private network settings and Public network settings
click Ok.
Disable the firewall for vm2 just like it was done for vm1.
Next, in vm1 click search icon at the bottom of the page and search for powershell
Select PowerShell from the search result listing.
After PowerShell completes launching, type ping vm2 into the interface.
If you can see the following display in the image below, that means the connection was successful. I have successfully pinged vm2 from vm1.

CONCLUSION

In this article we have done the following:

Created a Virtual Network and a Subnet
Deployed two virtual Machines onto the virtual network
Configured them to allow one virtual machine to ping the other within that virtual network, and
Tested the connection of the two virtual machines in the network.

Another article about virtual networks in Azure can be found here

Photo by Shubham Dhage on Unsplash

How to deploy a hub virtual network in Azure.

Tunde Oretade — Thu, 11 Jul 2024 21:53:32 +0000

Introduction

This article provides steps for how to create an Azure-based hub virtual network (VNet) with subnets and address space from scratch, as well as how to configure a virtual network peering. This is to allow for the virtual networks to communicate with each other securely and privately.

Scenario

A hypothetical Web Application requires network isolation and segmentation in a network for secure and private communication. The virtual networks and subnets will be created in the following steps.
Segmentation is the act of dividing the virtual network into smaller physical or logical components. This is to increase security and data protection.

Step 1: Create hub and virtual networks and subnets

I. Creating the virtual networks

Open a browser and navigate to the Azure portal and login.
To create a Virtual Network, click the hamburger icon at the top left hand side corner of the portal.
In the displayed pane, select Virtual Networks.
In the “Virtual Networks” portal pane, select + Create.
At the Resource group label select "create new" to create a new resource group. Give the resource group a name and click Ok. Keep in mind that this is the "parent directory" for the virtual networks to be created.
Also, give a name to the virtual network at the "virtual network name" label.
Select a Region from the dropdown list at the Region label. In this case, I selected East US.
Next, Select the IP Addresses tab at the top of the page.

II. Create subnets for the first Virtual Network.

At the dropdown menu displayed above the address space box on the displayed page, check that the dropdown is set to Add IPv4 address space
In the address space box, change Subnet address range to 10.1.0.0/16 (This is usually the default IP address so you may not need to change it in this instance).
locate a pen icon at the bottom corner, in the address space box (next to the garbage can icon). Click on this icon to edit the default Subnet name.
Change Subnet name to frontend
Also, change Subnet address range to 10.1.0.0/24 using the size label. Leave all other settings as their defaults.
Click Add to close the Edit Subnet pane. This
completes the creation of the first Subnet.
The next step is to create the second subnet. As you can see, the
frontend subnet is listed in the box. We need to create another
subnet in this virtual network. Again, locate the pen
icon at the bottom (next to the garbage can icon). Click on this icon to
add another Subnet.
Also, change the subnet name to backend, then change the
Subnet address range to 10.1.0.0/24.
Again, leave all other settings as their defaults. Click Add to close the edit subnet pane.
Select Review + Create to validate the configurations and Create to create the first virtual network.

III. Creating the second virtual networks

Creating the second virtual network is similar to creating the first virtual network.
click the hamburger icon at the top left-hand side corner of the Azure portal.
Again, in the displayed pane, select “Virtual Networks”.
In the “Virtual Networks” portal pane, select “+ Create”.
At the Resource group label select from the drop-down menu the first Resource group that was created.
Also, give a name to the virtual network at the "virtual network name" label. Here the name I supplied was Hub-vnet.
Select a similar Region from the dropdown like the first virtual network list at the Region label. In the previous virtual network, I selected East US.
Next, Select the IP Addresses tab at the top of the page.
set the IPv4 address space to 10.1.0.0/16

IV. Create a subnet for the second Virtual Network.

In the address space box, locate a pen icon at the bottom (next to the garbage can icon).
Click on this icon to edit the default Subnet name.
At the flyout pane, change subnet purpose to Azure Firewall from
the Default settings.
Change Subnet name label to AzureFirewallSubnet
Also, change Subnet address range to 10.1.0.0/26.
Leave all other settings as their defaults.
select the save button to Close the edit Subnet pane. This
completes the creation of the Subnet for the second virtual network.
Select Review + Create to validate the settings.
After validation is complete select the Create button to create the
second virtual network and watch the process complete deployment.

Step 2: Setup a peer relationship between the virtual networks

Once the deployment is complete for the second virtual network, navigate back to the portal. In the search bar type resource groups and select Resource Groups from the results.
Select the required Resource group in the main pane and confirm that both virtual networks have been deployed.
Setting up a peer relationship between the two virtual networks aims to allow traffic to flow in both directions between the app-vnet and hub-vnet virtual networks.
In the Portal and the resource group view, Select the first virtual network created from the table. In my case it was the app-vnet virtual network.
On the app-vnet overview page select settings the left-hand sidebar of the portal.
Scroll down and select peerings to add peering.
In the app-vnet peerings pane, Select + Add.
Fill out under the Remote virtual network summary heading supply a
name for Peering link name with app-vnet-to-hub.
.
Select the first virtual network from the drop-down.
Scroll the page down to the Local virtual network summary heading.
Fill out the Peering link name with hub-to-app-vnet.
Leave all other settings as their defaults. Select Add to create the
virtual network peering.
You should see a notification at the top right of the page that says
Adding virtual network peering
Once the process completes, and after the configuration updates,
this validates that the Peering status is set to Connected.
(you may have to refresh the page to see the updated status)

Conclusion.

This article explains how to provide network isolation and segmentation for a web application, in an Azure virtual network with subnets with address space. We have learned the following:

Creating virtual networks
Creating subnets within the virtual networks, and
Configuring virtual networking peering which means allowing two or more virtual networks to connect and appear as one for connectivity purposes.

It's been great sharing my journey into cloud engineering and I hope to see you soon on the other articles.

Cover Image by Alina Grubnyak on Unsplash

Setting Up a Linux Virtual Machine with Azure & Nginx on a MacOs using Password Authentication (Part I)

Tunde Oretade — Wed, 29 May 2024 03:41:40 +0000

Introduction

This is the first installment of a two-part post focused on creating a Linux virtual machine with Azure. If you have been following my journey into cloud development, I have written about setting up a Windows virtual machine in Azure too.

Two authentication approaches can be used to set up the Linux virtual machine. This post will focus on one which is the password authentication

As I have suggested in previous posts about setting up virtual machines, having a Microsoft and an Azure account is a prerequisite for following the steps in this post.

Step 1: Create a Linux Virtual Machine

Log in to Azure portal
Search Virtual Machine using the search bar at the top of the page.

Click the + Create icon at the top of the page or click the Create button at the bottom to create a virtual machine.

Basics Tab

Under Project details, name the Resource Group or choose a Resource Group

Next, give the Virtual Machine a name.

At the Region label, select an appropriate label.
For the Availability Options label, select Availability zone.

At the Availability zone label, select zone 2 (I selected zone 2 in mine. However it may be different in yours).

Security type label should be set at Trusted launch Virtual Machines

The Image label should be set to Ubuntu Server 22.04 LTS x64 Gen2

VM Architecture should be set to x64.
Do not tick Run with Azure spot discount box
Set Size to Standard_B2as_V2..
Do not tick Enable Hibernation box as well.

Under Administrator Account heading, Set Authentication type to Password. I will handle SSH Authentication in part two of this post.

Set Username, Password and confirm Password subsequently.

At Public inbound ports label, select Allow selected ports, and
for the Select inbound ports label, at the dropdown, tick HTTP (80) and SSH (22). HTTP was selected as part of the ports because I will access the server via a browser at some point in this post.

Monitoring Tab

Click Monitoring at the top of the page
Click Disable to disable diagnostics. This is to prevent third-party access.

Tags Tab

Under the Tag Tab it is ideal that name and value are created for the resources. Give the resource a name and value In the annotated part of the image below. They help to categorize resources. Both the name and value are called Tags.

Click the Review + create tab or the Review + create button at the bottom of the page.
Click the Create button to complete the configuration process.
After the complete deployment, click the go to resources button. This completes the creation of the virtual machine.

The next thing to do is to increase IP address timeout to prevent untimely shutdown.
At the Virtual Machine overview page, click on the IP address at the IP address label
This re-directs to an IP configuration page. While on the page move the idle timeout slide to the right hand of the page.

Click the Save icon at the top of the page.
Close this page by clicking the close icon at the top right.
Copy the IP address at the Virtual machine interface.

Step 2: Connect to the Linux Virtual Machine

To connect to the Linux Virtual Machine, Open the terminal.
Type in ssh username@IP address at the terminal. The Username used here was created while providing information for the Administrator account in the above steps, while the IP address was copied when the deployment process was complete.
The prompt asks if you want to continue, type yes

Provide the required login password when prompted again.
Then the prompt changes to a combination of the username@virtual_Machine_Name. This is evidence of a connection to the Linux Virtual Machine.

Step 3: Install Nginx Server in the Virtual Machine

The next step is installing a Nginx server in the Linux Virtual machine. To do this, log in as the root in the Virtual Machine.
At the terminal type in sudo su to change to root user.
At the next terminal/prompt type apt install nginx to install ngix.
Select yes at the next prompt. This completes the Nginx installation process.

Step 4: Testing the Linux virtual Machine via browser

To test if everything works perfectly, copy the Linux Virtual Machine IP address from the Azure portal and paste it into a browser. If you can see the image below in your browser, it means everything is working well.

Conclusion

This concludes my post on creating a Linux Virtual machine in Azure using Password Authentication.
It is advised that the resource created in the Azure portal be deleted when not used.
In the next post, I will write about creating a Linux Virtual machine in Azure using SSH Authentication.

Prototyping different storage scenarios for an IT department in Azure Portal.

Tunde Oretade — Sun, 26 May 2024 15:38:51 +0000

Introduction

In this post, I'll walk you through the process of providing Storage for a fictitious IT department, in the Azure portal. For the department, the data isn’t important enough to back up and doesn’t need to be restored if the data is overwritten or removed.

Prerequisites

Before we start, you'll need a Microsoft Account and an Azure free trial account. I covered opening a free trial account here

Step 1: Creating a resource group

Go to the Azure Portal Dashboard, and at the search bar - at the top level of the page - search and select Resource groups. This navigates to another page. While on that page select + create. On the next page, you are required to name your resource group. Go ahead and name your resource group. Then select a region. At the bottom of the page select the Review + create button to validate the resource group.
Select the 'create' button to deploy the resource group. The image below shows the created resource group.

Step 2: Creating and deploying a storage account

On the page of the resource group and the search bar - at the top level of the page - search and select Storage Accounts.

This navigates to another page. While on that page select + create at the upper left of the page or click on the create storage account button on that page.

This next page has 6 Tabs namely Basics, Advanced, Networking, Data protection, Encryption, Tags and Review + create.

At the Basics tab, select the Resource group label under the project details section and select the Resource group created in Step 1.

Next, Under the Instance details section, give the storage account a unique name, select the (US)East US option at the Region label, and for the Performance label, select the standard radio button.

Accept the default Redundancy label option as shown. Afterward, select the Review + create button on the page and subsequently the "Create" button.

Wait for the storage account to deploy.

After successfully deploying, click the go to resource button.

Step 3: Configure settings in the Storage Account.

I: Data in this storage account does not need to be highly available.

We want to configure this storage account with the most basic settings. We don't have to worry if data isn't highly available. To do this, select Data Management at the left-hand side of the page and the Redundancy blade.

Select the Locally redundant Storage (LRS) option from the Redundancy label. The reason for this is that "the data isn’t important enough to back up and doesn’t need to be restored if the data is overwritten or removed". As a result, High availability isn't required. This means the redundancy can take the least available option which is Locally redundant Storage.

Click save at the top of the page.

Previously, 2 locations may have shown up on the map displayed on this page. However, since we selected the Locally redundant Storage (LRS) option from the Redundancy label, only one location will be displayed on the map. Refresh the page if this isn't displaying.

II: Storage account should only accept requests from secure connections.

The next configuration to set is to make the Storage account only accept requests from secure connections. To do this, follow these steps:

Locate settings at the left-hand side of the page, and select the Configuration blade.

At the page displayed, confirm that Secure Transfer required is Enabled

III: Storage account should use a TLS version.

For the Storage account to use a TLS version,

go to settings
select configuration blade, -Then, set Minimal TLS Version to version 1.2

IV: Request to the storage account is disabled until needed

For disabling requests to the storage account until required,

Select Settings, then
Select the Configuration blade.
In the Allow Storage Account key access label, select the Disabled radio button.
Select the Save icon at the top level of the page.

V: Allow Storage Account to permit public access from all Networks.

For the last configuration in this task which is to permit public access from all Networks, follow the steps listed below:

At the left-hand side of the storage account page, select Security + networking
Select the Networking blade
set Public network access to Enabled from all network

Click the Save icon of the page to save the changes.

Conclusion

To avoid unnecessary charges, delete your resource group if you will not be using it. You can do this from the Azure portal by navigating to your Resource group and clicking the "delete resource group" button.
In this post, we successfully created a Resource group which is a container for our storage account. We adjusted some basic settings for the storage account and saved these settings. Remember to monitor your usage to stay within the free tier limits and delete resources when they are no longer needed. Stay tuned for more posts on cloud development with Azure!

Cover Image by Markus Spiske on Unsplash

How to deploy a Windows Server (with IIS web server role) in Azure Portal on MacOS

Tunde Oretade — Sun, 26 May 2024 15:38:02 +0000

Introduction

This post is about deploying a Windows Server in Azure Portal on MacOS. Previously, I have written about deploying a Windows 11 OS in the Azure portal here. Before you start following this guide, get a Microsoft account and an Azure account. If you have followed this post, deploying a Windows Server in Azure Portal will be a walk in the park. Let's get to it!!

Step 1

Create a Virtual Machine.

Access the Azure portal As shown in the image below.
Search for "virtual machines" in the search bar at the top level of the page. Select virtual machines from the list of results.

Select either the + Create option at the top left side of the page displayed, or click the Create button with a dropdown arrow at the bottom of the page.
Select Azure virtual machine from the list, and then it will navigate to the "create a virtual machine" configuration page.

Basics Tab

Under the Basics Tab supply information for the Windows Server virtual machine as follows:

Project Details

By now the Subscription label under project details should have a name, otherwise give Subscription a title.
At the Resource group label select Create new to either create a new resource group or use an existing group from the list of resource group earlier created.
Click the "ok" button to accept the given name.

Instance Details

At the Instance Details subhead, provide a name for the virtual machine at the Virtual machine name label.

For the Region label select a suitable datacenter region.

For the Availability options label, select Availability zone as the preferred option. This permits the selection of data center zone(s) in the preceding label.

Next, move to the Availability zone. This label allows for selecting multiple zones, but for the post, I selected only one zone. Selecting multiple zones means there is a need for a load balancer.

For the Security type label, select Trusted launch virtual machinnes option.

At the Image label, select the preferred Windows server option from the dropdown list.

The VM architecture should be kept at x64, and keep Run with Azure Spot discount unticked.
At the Size label, select Standard_B1s - 1 vcpu, 1 GiB memory size and do not tick the Enable Hibernationn box.

Administrator account

Create a Username for the Windows Server and a Password

Inbound port rules

Allow selected ports at the Public inbound ports options
From the Select inbound ports drop down list, select both HTTP (80) and RDP (3389) as the ports of communication.

Monitoring Tab

Under the Monitoring Tab it is desirable to disable Boot diagnostics.

Diagnostics

At the Boot Diagnostics label, set it to Disable

Tag Tab

Under the Tag Tab it is ideal that name and value are created for the resources.

At the annotated part of the image below, give the resource a name and value. Both the name and value are called Tags and they help to categorize resources.

The next step is to click the Review + Create button at the bottom of the page or the Review + Create tab at the top.

When it has completed validation, there is a pale green banner and a green check mark at the top of the page saying "Validation passed"

click the create button at the bottom of the page to initialize deployment.

When the deployment is completed there is a notification at the top page that says "Your deployment is complete"

click the Go to resource button to go to the newly created resource page.

At the right-hand side of the page, look for the "Public IP address" label, and click on the IP address.

This navigates to a page to increase the idle timeout from 4 minutes to the maximum (usually 30 minutes)

Click on the save icon at the top of the page.

you can then close the IP configuration page after making these changes by clicking the close button at the top right part of the page.
Back at the Virtual Machine overview page, select Connect at the top level part of the page or the left-hand side of the page.

This directs to the connect page.
Click the Select button at the local machine card with the heading "Most common".
On clicking select, several processes are triggered to validate prerequisites before configuration. Until there is a green check mark and
"configured" at the annotated arrow in the image below, the next step can't start.

Once the processes are completed and there are green check marks and "configured" at the annotated locations in the image above, click on the Download RDP file as shown below.

This downloads the RDP file required for powering the Windows server Virtual machine that has been created. Check your default download location in your local machine for this file.

Step 2

Launch the Virtual Machine.

To check if the Windows Server virtual machine works, log in using previously created credentials at the Administrator Account section above. Before signing in, Mac users need to go to the App Store, download and install the Microsoft Remote Desktop app. After installing the Microsoft Remote Desktop app, double-click the downloaded RDP file.

Supply the password as required.
Click continue at the next prompt

If the correct login credentials are submitted there will be a Windows Server starting page like below.

This automatically launches the Server manager

This is followed by a setup page below.

There is a need to also install a Windows server iis role in the server and there are two ways to do this. The first approach is using the server manager setup and the second one is via the terminal. In this post, I will be using the terminal.
Close the server setup page and search PowerShell at the hand lens icon at the bottom of the virtual machine page. Type "PowerShell" to search.

-Right-click to launch the PowerShell terminal as an Administrator

type in the following command in the PowerShell terminal: install-WindowsFeature -name Web-Server -IncludeManagementTools This creates the iis role in this server.

When the role installation is complete, go to the Azure portal Windows Server Virtual Machine page, copy the Public IP address, and paste it on the browser.

if the virtual machine is properly configured following these instructions, you should see something like below:

Conclusion

With all the steps listed above, I have created a Windows Server virtual machine in an Azure portal. It is advised that the resource group in the Azure portal be deleted. However, before deleting the resource group in the Azure portal, there is a need to shut down the Windows Server virtual machine on the MacOS.
This post describes a high-level approach to creating a Windows Server virtual machine on a MacOS computer. More posts on cloud DevOps with Azure will be coming up during my journey into cloud development.

cover image by Taylor Vick on Unsplash

Setting Up a Windows 11 Virtual Machine with Azure on a MacOs

Tunde Oretade — Sat, 18 May 2024 02:18:48 +0000

In this post, I'd like to share how I created a "resource" in Azure portal. By definition, a resource in an Azure portal is a service required to create a product or solution. In Microsoft Azure, everything needed for a business solution is colloquially called "resource". In this case, the resource that I will be creating in Microsoft Azure Portal is called a "virtual machine". Virtual machines are scalable computing resources that can be used to deploy applications on the cloud. VMs -short for virtual machines - are listed under Microsoft Azure's Infrastructure as a Service (IaaS) category.

The first step in creating a virtual machine is getting a Microsoft account. Once you have a Microsoft account click this link to create an Azure free trial account.

Click on the "Try Azure for free" button. This takes you to the page below.

Scroll and click "sign up" for the Azure free account card.

The next page will ask for your Microsoft login details. On the next page, fill in the required information. You need to enter your credit card details at some point during the registration. Note that only $1 is deducted initially for the 30-day free Azure service and after 30 days, Microsoft begins to charge for the services used.

This Free Azure account is designed to offer customers free tier services to test new applications and evaluate the benefits of cloud computing. When you start using Azure with a free account, you get a $200 credit to spend in the first 30 days after you sign up.

At the Azure platform (after completing the Registration ) like the image below:

There are three options available to create a virtual machine resource. The first approach is the search bar labeled "1" in the image above. At the search bar, you can search for "virtual machine", and from the dropdown, select "virtual machine" from the list. The second approach is labeled as "2" and in this option, you can select the virtual machines icon to create a virtual machine. The third option is to click the "Create a resource" icon. Either way allows for the creation of a virtual machine.

After selecting the "Virtual Machines" icon and the "create" button

that appears on the next page displayed, select "Azure Virtual Machine" from the list.

Basics Tab

This takes us to the "Create a Virtual Machine" page below:

There are 8 tabs at the top level of that page, and the first tab of concern is "Basics" annotated in a red rectangle.

Project details

Below the top-level tab is the "Project details" section which consists of "Subscription" and "Resource group". The "Subscription" gives you the admin privilege to create resources. "Resource group" is a container for grouping similar items in Azure. In Azure, there will be a need for a container to group similar things. Give the "Subscriptions" and the "Resource group" labels names. I gave mine "Azure subscription 1" and "AzureRG" as shown in the above image.
For the "Resource group" label select "Create new" to give it a name.

Instance details

The next section of concern is the "Instance details" labeled "1" in the below image:

Virtual machine name

Under this section there are subheadings like:
"Virtual machine name", "Region", "Availability Options", and "Availability zone" just to mention a few.

The Virtual machine is just like a computer in the cloud, and normally your physical computers have a name. So in this section, give the virtual machine a name. I named mine "BusinessVM" as shown in the image below:

Region

Next, move to the "Region" label. "Region" describes a geographical location where data centers are located. The Region selection should be done based on the understanding of the availability of support and other factors.

Availability options

The next label is the "availability options".

This infers that the user should set up alternatives per adventure if something goes wrong. As you can see in the image below, I chose the "Availability zone" option.

Availability zone

After "availability options" the next label is "Availability zone". This is a drop-down list of available zones for users to select the number of data centers to use. Availability zones in Microsoft Azure are made up of physical & logical data centers that have been segregated. This drop-down list is made up of zone 1, zone 2, and zone 3 and they are interconnected with highspeed internet network, cooling, and power. I selected zone 1 and zone 3 in the image below.

It is possible to select all three zones, but my preferred size (discussed in 3 labels below ) dictates the number of zones I can use in my virtual machine. Note also that the number of zones selected will alter the virtual machine names. In this example, I selected 2 zones: "zone 1" and "zone 3". As a result, I will end up with 2 virtual machine names called "BusinessVM-1" and "BusinessVM-2". This means I will have 2 virtual machines distributed between the 2 zones I selected earlier.

Security type

For the "security type" label, select "Trusted launch virtual machines" from the drop-down menu. (see below)

image

Next, it is required that I select the Operating System that will be running in the virtual machines. This post is about Setting Up a Windows 11 Virtual Machine. So at the "image" label, select the drop down list to reveal operating systems that can run in the virtual machine being created.

I selected Windows 11 as the preferred Operating System.

VM Architecture

The "VM Architecture" label radio button selection should be retained at "x64".

Run with Azure Spot discount

Do not tick "Run with Azure Spot discount" box

size

At the "size" label, there was a warning in "2" in the image below saying "This size is not available in zone 1,2,3. Zones 1,3 are supported". It says the "Standard_B1s..." isn't available in zone 1,2,3. This made me select the "see all sizes" in "3" below to see my options.

I am taken to a page titled "Select a VM Size"

This displays the various sizes that can be used with the virtual machine being created. I selected the "B Series v2" list on the page as shown in the image above. This further shows a sub-list under the "B Series v2". In the image below, I selected the "B2as_V2" size option.

After this selection click on the "Select" button at the bottom part of the page.

This returns to the "Create a Virtual Machine" page. The next section of focus is the "Administrator Account".

Administrator Account

This section requires that a "username", to be used in the operating system is supplied, as well as the "password". I have set my "username" as "azureUser" and my password too.

Inbound port rules

In the image below, "inbound port rules" is captured in the red rectangle ("1"), and it has 2 labels namely: "Public inbound ports" and "select inbound ports".

For the first label "Public inbound ports" I selected "Allow selected ports" while for the second label, I selected "RDP (3389)" from the list of options. This applies to only Windows-based Operating Systems. For Linux-based Operating Systems, "SSH(22)" applies.

Licensing

The last label in the "Basics" Tab is "Licensing".

Tick the box to "confirm I have an eligible Windows 10/11 license.."

Networking Tab

At the "Networking" Tab, scroll to the "Load balancing" section,

and select the "None" radio button under the "Load balancing options" label

Monitoring Tab

The Monitoring Tab has 3 headings namely "Alerts", "Diagnostics" and "Health".

The focus of this post is "Diagnostics" and the "Boot diagnostics" label. I selected the "Disable" radio button.

Tags Tab

Tags are name/value pairs that enable you to categorize resources and view consolidated billing by applying the same tag to multiple resources and resource groups.
In the image below, I wrote "Department" as the "Name" and "IT" as the "Value". In the "Resources" column, I selected "All resources".

Review + create

This is the last button to select after following and applying the above-mentioned steps. "Review + create" will validate all the settings supplied and proceed to the next step in creating the "virtual machine". If there is an issue with any of the settings, an error will show up on the affected Tab(s)

when Azure portal is done validating all the settings provided, the page below will display "Validation Passed". After that, you can then go ahead and click the "Create" button ("2") at the bottom of the page to create the virtual machine.

Subsequently, the "create" button triggers a page showing the deployment's progress. As you can see in the image below, "Deployment is in progress" is displayed and labeled as "1".

At the same time "2" in the image above shows the stage of deployment of the resource "BusinessVM-1" and "BusinessVM-2".
When the deployment is successful, the page will display "Your deployment is complete" as shown in the image below.

The next step is to click the "Go to resource" button on the page displayed to go to the created resource. (See below)

The next page contains details about the Virtual Machine. The virtual machine's name is displayed at the top left corner of the page. Below the name is a "search bar" and a sidebar for quick access to tools.

The next step is to change the "idle timeout" of the virtual machine. On the page look for the "Essentials" panel on the right-hand side of the sidebar. Search for the "Public IP address" label as shown below,

and click on the IP. This navigates to the "Configuration" page. The "Idle timeout(minutes)" label has a slider. By default, the idle timeout in minutes is set at 4.

The desirable thing to do is to set it to the maximum to prevent the virtual machine from timing out. So the slider is dragged from the left-hand side to the right-hand side of the slider. Now the idle timeout in minutes is set to 30: the maximum timeout allowable. When this is done click on the "Save" icon at the top of the page.

It returns to the virtual machine page. The next step is to locate the "Connect" button on the sidebar. This will connect the virtual machine after all the configurations performed earlier.

Once the "connect" button is selected, it sets the machine up for another round of validation (see image below). Under the "Native RDP" bar, the labels numbered "2" & "4" indicate the validation process.

Once the validation is complete, labels "1" to "3" will display a green check mark, and label "4" will display "Configured".

Once this is completed look out for label "1" in the image below and click the "Download RDP file"

It's 90% done if you're following these steps on a MacOS computer.
The "RDP" file is downloaded into the downloads directory on a Mac.

The RDP file represents the Windows 11 virtual machine that was created. To check if it works, log in using the credentials created previously. Before signing in, Mac users need to go to the App Store, download and install the Microsoft Remote Desktop app. After installing the Microsoft Remote Desktop app, double-click the downloaded RDP file.

The dialog box will request the password created at the "Administrator Account" subheading above.
If the correct login credentials are submitted there will be a Windows 11 starting page like below.

This is followed by a setup page below.

Click the "Accept" button on this page, and it displays the Windows 11 desktop.

With all the aforementioned steps, I have created a Windows 11 virtual machine on an Azure portal.

The virtual machine runs on a free account, and if left running on the MacOS computer and the Azure portal, it may drain out the free $200 credit. So it is advised that the resource group is deleted. However, before deleting the resource group in the Azure portal, there is a need to shut down the Windows 11 virtual machine on the MacOS. Since the Windows 11 desktop is still on, it needs to be shut down properly as it is done for any physical system. The power button for the Windows 11 virtual machine is located at the bottom labeled "1" in the image below.

On clicking this button, a fly-out card of options appears. (see label "2" below)

From this fly-out card, the Windows 11 virtual machine on MacOS can be shut down.

Next, the resource group should be deleted to prevent incurring charges. I went back to the Azure portal page as shown below.

My resource group labeled "1" above is "AzureRG". Another way to locate the resource group is to search for it at the top-level search bar on the page. Click on the resource group name and it navigates to the resource group page. At the upper part of the page, there is a "Delete resource group" option.

Click on the "Delete resource group" option, and a notification box on the upper right-hand of the page shows "Deleting resource group AzureRG" like in the image below.

The process completes by showing "Deleted resource group AzureRG" in the notifications bell icon at the upper part of the page.

This post describes a high-level approach to creating a Windows 11 virtual machine on a MacOS computer. More posts on cloud DevOps with Azure will be coming up in my journey into Cloud development.

Cloud Computing Key concepts

Tunde Oretade — Sat, 11 May 2024 15:27:37 +0000

BACKGROUND

Recently, I have taken an interest in the deployment of applications to the cloud and the basics of DevOps. From my point of view, it is the next thing to learn after my foray into software development. Cloud computing is an area of software development that I'm not very familiar with, so I've decided to spend the next five months diving into it and eventually pursue a career as a cloud developer.

During this time, I'll be sharing my discoveries in a series of posts over the next few months and beyond. Be prepared for a lot of articles that showcase my learning journey. In this first post, I'll be discussing some crucial concepts in cloud computing that illustrate why it's beneficial for businesses that invest in cutting-edge technology.

WHAT IS CLOUD COMPUTING?

Cloud Computing is a computing service deployed over the World Wide Web a.k.a Internet. The advantages of cloud computing include:

Adaptability
Scalable Services

WHAT IS VIRTUALISATION?

Cloud Computing is based on the concept of Virtualisation, but what is Virtualisation? Virtualization - as I'd like to paraphrase - is a technology that involves the creation of virtual replicas/virtual instances of computer resources like databases, servers, operating systems, or even applications. These replicas/instances operate independently of one another on the same physical hardware without interference. With virtualization, users can access applications without requiring physical hardware. Also, Data centers can leverage virtualization to save power use and enable quick recovery from disasters.

CLOUD COMPUTING SERVICES

Firstly, you should know that there are 3 kinds of services in cloud computing namely:

Infrastructure as a Service
Platform as a Service
Software as a Service

Individuals/businesses must choose the service that will work well for them. However, before choosing any service, it is important to know how these services will benefit them, and the benefits are discussed below.

BENEFITS OF CLOUD COMPUTING IN DETAILS

HIGH AVAILABILITY

This characteristic exhibited by any cloud computing service infers that the system, component, or application can operate at a high level, continuously, without intervention, interruption, or outages to the services while running. According to weka.io, High availability allows a system to continue functioning, even when certain components fail.
Furthermore, weka.io added that "saying a cloud infrastructure is “highly availability” actually means something more specific than just “usually available whenever we need it.” Instead, availability is typically rated on the number of “nines” represented in its percentage of uptime per day, week, and year:

99% uptime = two nines
99.9% uptime = three nines
99.99% uptime = three nines

And so on. To frame these percentages, a Highly Available cloud system with three nines would have a Mean Downtime per day of roughly 1.44 minutes and an annual downtime of only about 43 minutes."

FAULT-TOLERANT

This refers to the ability of any cloud system to recover quickly from unexpected disruptions they may have encountered while running tasks. Practically a system can’t be made entirely error-free. hence, systems are designed such that in case of error availability and failure, they work properly and produce the correct results.

SCALABILITY

Scalability in cloud computing refers to the ability of a cloud infrastructure to scale up or down resources to meet changing workload demands. It allows businesses to easily add or remove computing resources as needed manually or automatically without significant hardware investment or infrastructure changes. For example, when many users log in to use an application, scalability ensures that traffic from the users is managed to cater for peak periods and off-peak times.

GLOBAL REACH

The Global reach or distribution of cloud providers' data centers permits businesses located close to these data centers in different parts of the world to start quickly and scale out effectively. Also, User requests are responded to on time when the business data is stored near customers. This proximity ensures a quick application response which is useful for a positive user experience.

AGILITY

Cloud agility is the ability to quickly develop, test, and launch applications in a cloud-based environment using cloud resources. Startups and other customers can leverage agility to launch swiftly their ideas without having to spend on physical equipment which may delay the launch of their product.

ELASTICITY VS SCALABILITY

While scalability focuses on expanding the capacity of cloud systems to meet rising traffic from users or workloads, Elasticity focuses only on meeting current demand intuitively without over or under-provisioning. According to wrike.com "Scalability is your long-term strategy, ensuring your tech grows with your business. Elasticity is your short-term solution for handling unexpected changes without breaking a sweat."

These concepts are vital for anyone learning about cloud computing or anyone whose desire is to become a cloud developer. That's all I have for this post. I hope to share more of my progress as a cloud developer soon.

Cover Image: Growtika on Unsplash.

Hamming (coding challenge) Part II

Tunde Oretade — Tue, 29 Nov 2022 12:57:14 +0000

Hamming coding challenge Part I

This article is the second part of Exercism's Hamming coding challenge. Initially I had explained my first solution and the lesson learnt as hinted by Exrecism. This second part focuses more on how I refactored my initial solution as seen in part I.

The refactored code goes like this:

class UnequalStrandError < ArgumentError
  def initialize(error_message = 'Strands must be of equal length')
    super
  end
end


class Hamming
  def self.compute(first_strand, second_strand)
    new(first_strand, second_strand).distance
  end

  attr_reader :distance, :first_strand, :second_strand

  private

  def initialize(first_strand, second_strand)
    @first_strand = first_strand
    @second_strand = second_strand
    validate
    @distance = nucleotides.count { |n1, n2| n1 != n2 }
  end

  def nucleotides(first_strand, second_strand)
    first_strand.chars.zip(second_strand.chars)
  end

  public

  def validate
    raise UnequalStrandError unless first_strand.length == second_strand.length
  end
end

From this second iteration you can observed that it is now leaner and readable. However, what did do to make it leaner and readable?
As usual I will start with the UnequalStrandError class. In the new code I created a function called validate. This will take care of raising errors whenever any error is encountered in the code. Note that I now have a one line code:

 raise UnequalStrandError unless first_strand.length == second_strand.length

compared to what I had earlier to help handle raising errors:

 raise UnequalStrandError if first_strand.empty? && second_strand.size.positive?
    raise UnequalStrandError if first_strand.size.positive? && second_strand.empty?
    raise UnequalStrandError if first_strand.size > second_strand.size
    raise UnequalStrandError if first_strand.size < second_strand.size

Secondly I refactored compute as :

  def self.compute(first_strand, second_strand)
    new(first_strand, second_strand).distance
  end

The compute method in the above is a class method as indicated with the self prefix and also in compute body, I instatiated Hamming class and called distance on it.
The distance method is defined in initialize method:

  def initialize(first_strand, second_strand)
    @first_strand = first_strand
    @second_strand = second_strand
    validate
    **@distance = nucleotides.count { |n1, n2| n1 != n2 }**
  end

and it is defined as an instance variable which is then exposed using attr_reader method.

  attr_reader :distance, :first_strand, :second_strand

Note that @distance is a variable holding the result derived from nucleotides.count { |n1, n2| n1 != n2 }. Also the nucleotides method defined in the body of Hamming class handles the separation and zipping of first_strand and second_strand
In the initial code I had used the split() method to get an array from the string supplied but I found chars() to be effective as well. After creating the array I zipped both first_strand and second_strand array together. While using the zip() method this is what it does:

  first_strand = [G,A,G,C]
  second_strand = [C,A,T,C]
  first_strand.zip(second_strand)
  result = [[G,C],[A,A],[G,T],[C,C]]

After zipping I called the count() method on the zipped array and this method was able to get a count of items in the sub array that are not the same.

With this refactoring for readability, I learnt about self, and what self means in the context of this challenge. I understood that when self is used in a code, it refers to the class and in this case it is reffering to the class Hamming.
I also learnt a new trick: instantiating a class in a class method and calling a defined method in the class on it.

  def self.compute(first_strand, second_strand)
    new(first_strand, second_strand).distance
  end

When Hamming.compute is called, the new class instantiation will also call the method involved. This is a quick way of getting results instead of having to create new objects of class Hamming.
I also learned that, I can raise Errors in the initialize method to catch the errors thrown as quick as possible.

These are what I learned while solving the hamming coding challenge on Exercism. I will be solving more challenges on Exercism and do watch out for more articles on how I solved and refactored the challenges.

Hamming (coding challenge) Part I

Tunde Oretade — Tue, 29 Nov 2022 12:54:46 +0000

Hi Folks!! it's been a while since I wrote an article on what I have been doing lately. Currently I'm job searching, and in a bid to keep myself up to date, I decided that I will be solving coding challenges on the Exercism website daily using Ruby and also refactoring the solved code for readability.

For every challenge solved, I will be publishing my initial code iteration and the fully optimised version. I will also be describing lessons learnt while solving the coding challenge.
So hold on to your seats and enjoy the ride!

For starters, this article's focus will be on the Hamming coding challenge. According to Exercism, the anticipated lessons to be learnt are Advanced Enumeration, Loops,Conditionals, and Raising Exceptions. However I'm sure I learned more after I was done refactoring the initial solution.

For the Hamming challenge here is an abridged version of the instruction introducing the challenge:

Calculate the Hamming Distance between two DNA strands.
DNA strands are read using the letters C,A,G and T and Two
strands might look like this:

   GAGCCTACTAACGGGAT
   CATCGTAATGACGGCCT
   ^ ^ ^  ^ ^    ^^

They have 7 differences, and therefore the Hamming Distance is 7.
The Hamming distance is only defined for sequences of equal
length, so an attempt to calculate it between sequences of
different lengths should not work.

With the above instructions I set out to solve the challenge.
My initial solution produced the below code block:

class UnequalStrandError < ArgumentError
  def initialize(error_message = 'Strands must be of equal length')
    super
  end
end

class Hamming
  def self.compare_strands(first_strand, second_strand)
    first_array = first_strand.split('')
    second_array = second_strand.split('')
    first_array.each_with_object(container = []).with_index do |(item), index|
      second_array.at(index) != item and container << item or nil
    end
  end
  def self.check_strand_size(first_strand, second_strand)
    raise UnequalStrandError if first_strand.empty? && second_strand.size.positive?
    raise UnequalStrandError if first_strand.size.positive? && second_strand.empty?
    raise UnequalStrandError if first_strand.size > second_strand.size
    raise UnequalStrandError if first_strand.size < second_strand.size
  end
  def self.empty_strands(first_strand, second_strand)
    check_strand_size(first_strand, second_strand)
    return 0 if first_strand.empty? && second_strand.empty?
  end
  def self.compute(first_strand, second_strand)
    empty_strands(first_strand, second_strand)
    if first_strand.length == 1 && second_strand.length == 1
      first_strand != second_strand and 1 or 0
    else
      compare_strands(first_strand, second_strand).length
    end
  end
end

Well, the above code block got everything working, however we all know there are ways we can optimise this code block. Before I go into refactoring the code, would it not be okay if I explain what I did?

let's start with class UnequalStrandError:

class UnequalStrandError < ArgumentError
  def initialize(error_message = 'Strands must be of equal length')
    super
  end
end

The UnequalStrandError class is inheriting from the ArgumentError class, and I am initialising the error_message as 'Strands must be of equal length'. This is the message that will be displayed anytime the strands to be compared are of unequal size.

The UnequalStrandError class is also being raised in class Hamming see self.check_strand_size:

class Hamming

  def self.compare_strands(first_strand, second_strand)
    first_array = first_strand.split('')
    second_array = second_strand.split('')
    first_array.each_with_object(container = []).with_index do |(item), index|
      second_array.at(index) != item and container << item or nil
    end
  end

  def self.check_strand_size(first_strand, second_strand)
    raise UnequalStrandError if first_strand.empty? && second_strand.size.positive?
    raise UnequalStrandError if first_strand.size.positive? && second_strand.empty?
    raise UnequalStrandError if first_strand.size > second_strand.size
    raise UnequalStrandError if first_strand.size < second_strand.size
  end

  def self.empty_strands(first_strand, second_strand)
    check_strand_size(first_strand, second_strand)
    return 0 if first_strand.empty? && second_strand.empty?
  end

  def self.compute(first_strand, second_strand)
    empty_strands(first_strand, second_strand)
    if first_strand.length == 1 && second_strand.length == 1
      first_strand != second_strand and 1 or 0
    else
      compare_strands(first_strand, second_strand).length
    end
  end
end

Now to explain what is happening inside class Hamming. This class was setup to have class methods. Class methods (in the context of the Hamming class) do not require that a Hamming object is created before using any method in class Hamming. That is why you can see the self prefix before any method.

The def self.check_strand_size(first_strand, second_strand) raises the UnequalStrandError if one of arguments are empty? and if the other is not empty. it also raises error if the argument sizes are not the same.

The def self.empty_strands(first_strand, second_strand) returns 0 if first_strand.empty? && second_strand.empty? and also calls def self.check_strand_size

def self.compare_strands(first_strand, second_strand) is spliting the strings into an array. Using the first array produced, I am comparing if each item iterated on is not the same as each item in the second array produced:

first_array.each_with_object(container = []).with_index do |(item), index|
      second_array.at(index) != item and container << item
    end

if it is not the same, then the item is pushed and saved into another array called container

The last method is def self.compute(first_strand, second_strand). This method calls other methods I have defined earlier on like empty_strands(first_strand, second_strand) and also compare_strands(first_strand, second_strand). Since the answer required for the task is a number/integer, and I know that compare_strands returns an array if non-matching items, all I did was to get the size of the array and that is what produces the answer for the task.

So for example if I supply the following arguments to Hamming's compute method like so:

Hamming.compute('GAGCCTACTAACGGGAT', 'CATCGTAATGACGGCCT')

The expected answer is:

This code works like it is suppose to but there is still need to refactor the code for readability, and I will be doing this in Part II of this article. From the looks of things it seems I was able to match Exercism's expectations on what I will learn by solving this challenge. I used Advanced Enumeration, Loops,Conditionals, and also raised Exceptions. However more lessons will be learned in Part II of this article.

All About ActiveRecord Scopes

Tunde Oretade — Mon, 23 Nov 2020 19:57:27 +0000

Introduction

When I started learning Rails, I came across scopes while rummaging google for solutions to several Rails project challenges. During those times, Scopes were terrifying for me at first, and every opportunity I had, I'd sidestep using this incredible concept in any of my Rails projects.

The fact is that as one proceeds in our different software development journeys, there are some useful concepts and tools that are important to pick up to make our coding experience scale faster. I accepted scope because I later understood what it was all about and how it could help my backend coding journey.

In this article, I will be explaining what scope is and how to use it in different parts of any Rails application. I have set up an Equipment API with Rails, and this will be the examples utilized as the codebase in this write-up. Check out this repository to follow along. Let's dive in.

What Are Scopes

Scopes are SQL queries that you can build in any rails model. Often time, we tend to run similar queries in our rails console to query our database and also understand the structure of the result we are receiving before going further with the development of our applications.

According to the official ruby on rails guide, "Scoping allows us to make use of commonly-used queries which can be referenced as method calls on the association objects or models." The general expectation is that all scope bodies should return an ActiveRecord::Relation or nil. As a result of this, it makes it easy to call other ActiveRecord methods on it. Simply put, a scope is just a custom chain of active record methods. They are sets of pre-defined queries that can be chained to build other complex Queries.

Why use Scopes

Scopes help you D.R.Y out your active record calls and also keep your codes organized. Scopes make it easy to find the records you need at a particular time.

Also, using scopes helps us develop a healthy habit of keeping the heavy stuffs away from the controller. Rails convention suggests that implementation of the business logic should exist in Rails model instead of the controller/view.

Scoping also allows you to specify frequently used queries which can be referenced as method calls on the association objects or models.

Furthermore, during testing sometimes, you do not want your test to go into your database to fetch results. With scopes, this is achievable as it allows for easier stubbing.

Types of Scopes

Default Scopes vs Named scopes

Default scopes take the name default_scope when defined in the model and, they are scopes that are applied across all queries to the model in question. An example can be seen in the code block below:

class Equipment < ApplicationRecord
  has_many :requests
  has_many :customers, through: :requests

  validates :brand, presence: true
  validates :model, presence: true
  validates :equipment_type, presence: true
  validates :serial_no, presence: true
  validates :accessories, presence: true

  default_scope, -> {order("updated_at desc")}
end

Conversely, named scopes are scopes that take a name and are defined in a model for active record database queries. Typically, a named scope is made up of the scope keyword, followed by the name you want to give to the scope, and a lambda. Below is an example of a named scope:

class Equipment < ApplicationRecord
  has_many :requests
  has_many :customers, through: :requests

  validates :brand, presence: true
  validates :model, presence: true
  validates :equipment_type, presence: true
  validates :serial_no, presence: true
  validates :accessories, presence: true

  scope :not_available, -> {where("available = ?", false)}
end

The difference between both examples is glaring: one has a custom name and, one has a statutory name called default_scope. In the above example, the named scope above is called not_available. The following arrow sign -> (lambda) can be re-written as:

 scope :not_available, lambda {where("available = ?", false)}

note that -> is replaced with lambda. A similar approach can be used with the default_scope as well.

So in my rails console I can now do this:

 equip = Equipment.all
 equip.is_available

The lambda is what actually does the query implementation.
It will produce an ActiveRecord::Relation object, that contains list of available equipment.

This also gives us the opportunity to use the created scope in the controller in this manner:

  def index
     @equip = Equipment.is_available
     render json: @equip, status: 200
  end

  def index
    @equips = Equipment.all
    render json: @equips, status: 200
  end

  def availability
    @equip = Equipment.is_available
     render json: @equip, status: 200
  end

In the first code block, the route to index will always display only available equipment and not all equipment. However, in the second code-block, index will display a list of all equipment irrespective of whether it is available or not. Also, availability will only display a list of all equipment that is available if I hit the availability route. In this way, the controller is being used to decide what information is rendered. When it comes to which scope type to use, please avoid using default_scopes. Want to know why? see this article

Taking arguments
Named scopes can also take arguments like so:

class Equipment < ApplicationRecord
  has_many :requests
  has_many :customers, through: :requests

  validates :brand, presence: true
  validates :model, presence: true
  validates :equipment_type, presence: true
  validates :serial_no, presence: true
  validates :accessories, presence: true

  scope :not_available, ->(bool) {where("available = ?", bool) }
end

With the above arrangement, it is now possible to pass parameters from the controller when a request is made to the corresponding route.

Using Unscoped
If you have to work with default scopes, you may need to use the unscoped method to disable all currently applied default scopes. Let's work with an example:

  class Equipment < ApplicationRecord
    has_many :requests
    has_many :customers, through: :requests

    validates :brand, presence: true
    validates :model, presence: true
    validates :equipment_type, presence: true
    validates :serial_no, presence: true
    validates :accessories, presence: true

    default_scope -> {where("available = ?", true) }
  end

So we can now disable the scope in this manner

 equip = Equipment.first
 equip.unscoped

What can you do with scopes

Now let's see examples of what we can do with scopes:

chaining scopes

we can chain scopes together to build a bigger SQL statement. See the example below:

   class Equipment < ApplicationRecord
     scope :available, ->{where("available = ?", true) }

     scope :available_and_created, -> 
     {available.order(:created_at)}

   end

First, we define the scope we want to chain, and then define a second scope. In the body of the second scope, we will chain the first scope and an ActiveRecord method to make our query. The chaining can be seen, when we run the kind of query below in the rails console:

 Equipment.brand.is_available

Using Conditionals with scopes.

The scope named available, in the code block below is a typical example of how to use conditionals with scopes.

   class Equipment < ApplicationRecord
     scope :available,(bool) ->{where("available = ?", 
    bool) if bool.present? }
   end

Here we are saying, select all equipment if available is true.

Calling multiple scopes in a class method scope

This is achievable by using the send()method.
We can supply several scopes as arguments in the send method and call send on each one.
The code block below (chaining) allows us to dynamically call as many scopes as we want. The code block below is another way of writing scopes and it is called a class method.
We define a class method with the self keyword and it takes an array of arguments called multiple_method. This is then supplied to the send method in inject().

  def self.chaining(multiple_method)
    multiple_method.inject(self, :send)
  end

  Equipment.chaining(["scope_one", "scope_two"])

so in the controller we can have this kind of arrangement:

  def index
    if params[:equipment]
      args = params[:equipment][:multiple_method]
      @equip = Equipment.chaining(args)
    else
      @equip = Equipment.all
    end
  end

Summary & Conclusion

By now, using scopes should no longer be a difficult task. With scopes, we can easily create SQL queries on the fly.
Using the equipment API as examples in this article, we can now create a new scope from scratch, chain scopes together, use conditionals in scopes, and supply multiple scopes as an argument in another scope using the send method. The article focused strictly on creating scopes with the lambda approach. Another way to create scope is the use of a class method (which was mentioned when calling multiple scopes as arguments in a scope.).
Found this article to be useful? Please like, share or drop a comment below. You can also reach me via my twitter handle.

References

https://medium.com/@pojotorshemi/ruby-on-rails-named-scope-and-default-scope-74ee3db2a15f

https://devblast.com/b/jutsu-11-rails-scopes

https://jasoncharnes.com/importance-rails-scopes/

https://www.sitepoint.com/dynamically-chain-scopes-to-clean-up-large-sql-queries/

How to perfectly clone a website using Bootstrap 4.

Tunde Oretade — Thu, 10 Oct 2019 15:30:16 +0000

Setting up a layout for your responsive website should not take too much time. After planning the layout of the website, most developers tend to get stuck in the implementation stage.

This stage is critical as this is where you need to consider the behaviour of the website on various devices and if one can get this part right, 90% of your work is complete.

Where it all started

Recently, my knowledge of the Bootstrap framework was put to test. I was required to make an exact copy of the Newsweek website using Bootstrap. Now If you must know, the Newsweek website is a CMS built with Drupal.

Cloning a framework based website like Newsweek using vanilla HTML and CSS can be a pretty daunting task for beginners. However, It does not need to be daunting anymore as I am about to walk you through on how I cloned the newsweek website.

This project, took me between 4-6 days to complete and I had to do a 2-day refresher on bootstrap 4 (last time I used bootstrap was 3 years ago). Yep, I was that rusty 😓️.

There are lots of frameworks available for use out there, and setting up a quick layout is dependent on your knowledge of your chosen framework. If you are using bootstrap 4 framework like I am, you can quickly set up a layout in record time using both the bootstrap 4 framework and the flex-box included in this framework.

The new Bootstrap 4

The Bootstrap framework enables website designers and front-end developers to easily create a highly-responsive and good-looking modern website.

Recently, Bootstrap 4 has brought about so many changes from its previous versions. There are new grid classes, default flex-box, Sass instead of Less, cards replacing wells, panels, and thumbnails, and new utility classes, etc.

The biggest difference between Bootstrap 3 and Bootstrap 4 is that Bootstrap 4 now uses flex classes to control the layout of its components. It's now easier to design flexible responsive layout structure without using float or positioning.

Let's get started

In this writeup, I will be attempting to guide you on how to set up your layout to get started with for your frontend project, in the same way, that it was applied it in this demo project.

My focus will also be on explaining (using a few sub-sections) how I used Bootstrap 4 classes in the development of the main section.

The reason for the aforementioned is that similar Bootstrap 4 classes are in use in other sections.

Initial Setup

The setup for this project can be found in this repository. To get started, there is a
starter template that can be copied and used in your HTML file. It can be found here.

In the head tag, I included various links to resources that will be required in this project. These links correspond to resources from font-awesome(free icon website), Bootstrap CDN, and google fonts as well. Links to local resources were also provided. These links to additional CSS files to be used in the project for re-styling and resetting.
A reset file - reset.css - was also included to remove default styling for the HTML elements. See code snippet below:

<head>
 ...
  <link rel="stylesheet"
  href="https://use.fontawesome.com/releases/v5.8.2/css/all.css"
  integrity="sha384-oS3vJWv+0UjzBfQzYUhtDYW+Pj2yciDJxpsK1OYPAYjqT085Qq/1cq5FLXAZQ7Ay"
  crossorigin="anonymous">

  <link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/css/bootstrap.min.css" integrity="sha384ggOyR0iXCbMQv3Xipma34MD+dH/1fQ784/j6cY/iJTQUOhcWr7x9JvoRxT2MZw1T" crossorigin="anonymous">

  <link href="https://fonts.googleapis.com/css family=Roboto+Condensed:400,700&display=swap" rel="stylesheet">

    <link rel="stylesheet" href="css/reset.css">
    <link rel="stylesheet" href="css/main.css">
  <title>Newsweek clone</title>
</head>

In the <body></body> I had 3 main parts:

the <header></header>,
<main></main> and,
<footer></footer> section.

<body>
   <header class="heading ">..
   </header>

   <main class="container-fluid" ">..
   </main> 

   <footer class="footer-content">..
   </footer>
</body>

The Layout

On extra small devices, the section that gets displayed first, when viewing the Newsweek website is the "Top Story" and it stacks on the next section called "Featured stories", "Opinions", and the last section in the stack is "Newsletter".

On medium devices, however, the websites display a 2 column behaviour with the "Featured stories" as the first section to be displayed in normal flow appearance followed by "Top-story".

Scrolling down also shows different sections exhibiting visual behaviours different from what was observed on extra small devices. This visual behaviour continues to changes as the device screen gets wider and different sections are ordered based on the preference on the developer/client. The observed visual behaviours are also considered in the development of the main section.

The container class

I decided that the main section <div> should have a bootstrap class .container-fluid(As far as I'm concerned, using a .container class here will not match the exact Newsweek website layout). In Bootstrap 4, Containers provide a means to centre and horizontally pad your site’s contents.

The difference between .container and .container-fluid class are that the latter provides for width: 100% across all viewport and device sizes, whereas the former has a max-width pixel value.

Also, .container-fluid continuously resizes as one adjusts the width of the browser by any amount, while .container class resizes in chunks at determined widths, controlled by media queries. You can read more about the classes .container-fluid and .container here

Nested within the <main> tag are 2 <div>s. the first one was declared with a .row class and the second one with a .col-md-12 class.


<!-- MAIN SECTION -->
<main class="container-fluid">

  <div class="content row">
    <div class="left-content col-12 col-sm-12 col-md-12 col-lg-8 px-lg-3 order-sm-0">
   <!-- FEATURED STORIES -->
     <div class="row">
       <div class="featured-story col-12 col-sm-12 col-md-5 col-lg-5 mt-sm-4 mt-md-4 mb-sm-3 order-0 ">
       </div>
     </div>
   </div>


   <!-- OPINIONS -->
   <div class="right-content col-12 col-md-12 col-lg-4 order-sm-2">
   </div>

  </div>


  <div class="other-concerns col-md-12">..</div>

</main>

The row class

Rows are containers for columns and to implement it the Bootstrap way, column classes needs to be declared in divs with row classes. Bootstrap 4 documentation specifies that "In a grid layout, the content must be placed within columns and only columns may be immediate children of rows".

Each column has horizontal padding (called a gutter) for controlling the space between them. This padding is then counteracted on the rows with negative margins. This way, all the content in your columns is visually aligned down the left side.

The div with .content & .row classes also have 2 <div>'s corresponding to the opinions sub-section of the magazine and the featured stories section.

On large devices, "featured stories" section occupies 8 spaces .col-lg-8 while from medium to extra small devices they occupy 12. While on mobile devices, the featured stories will be the first section seen on the stack.

This is made possible by using the class .order-sm-0. However, the "opinions" section has a class .order-sm-2 which means it is the last section to be seen in class .content.

Also nested within the div with .content & .row class are 2 divs with class .left-content and .right-content both designated to hold "featured stories" and "opinion" contents.

The "featured stories" section is a div with .row class and wraps the featured stories and top story sections.

...
<div class="row">

   <div class="featured-story col-12 col-sm-12 col-md-5 col-lg-5 mt-sm-4 mt-md-4 mb-sm-3 order-0 ">..
   </div>

   <!-- TOP STORY -->
   <div class="middle-content col-12 col-sm-12 col-md-7 col-lg-7 px-sm-0 px-lg-3 order-1">..
   </div>

</div>
...

The divs with class .featured-story and .middle-content both have .order-0 and order-1 as well. The order class is a new addition to bootstrap 4 and it's derived from the new flexbox power with which bootstrap 4 was developed from.

By including this class to the divs, the containers can have the same visual behaviour which cuts across different devices. This means the div with class .featured-story will get displayed ahead of the div with class .middle-content from a normal flow appearance perspective.

The contents of .featured-story class has classes like .card to give them the card like appearance:

...
  <div class="card rounded-0 border-0  pb-sm-2" >
  </div>
...