Forem: Sadhan Sarker

Monitoring Cronjobs in GKE

Sadhan Sarker — Wed, 05 Apr 2023 18:57:20 +0000

The article discusses the importance of monitoring cronjobs in Google Kubernetes Engine (GKE). Cronjobs are time-based tasks that run periodically in a Kubernetes cluster, and it's essential to monitor them to ensure they are running as expected and to identify any issues or errors. The article provides insights into how to set up monitoring for cronjobs using various tools. By monitoring cronjobs, developers can proactively identify and fix issues, prevent downtime, and ensure the reliability of their GKE applications.

$ kubectl cluster-info

Output:

vi job.yaml

Input:

apiVersion: batch/v1
kind: Job
metadata:
  name: helloworld
spec:
  template:
    spec:
      containers:
      - name: busybox
        image: busybox
        command: ["echo", "Hello Kubernetes!!!"]
      restartPolicy: Never

Now hit this command to create job

$ kubeclt create -f job.yaml

Output:

job.batch/helloworld created

Now hit this command to watch all

$ watch kubectl get all

Every 2.0s: kubectl get all                                                                                                                      cs-6000-devshell-vm-0c4755a8-b531-4460-b60e-1fb2786e220b: Sat Jul  4 14:52:47 2020
NAME                   READY   STATUS      RESTARTS   AGE
pod/helloworld-dfr2k   0/1     Completed   0          4m25s
NAME                 TYPE        CLUSTER-IP   EXTERNAL-IP   PORT(S)   AGE
service/kubernetes   ClusterIP   10.8.0.1     <none>        443/TCP   23m
NAME                   COMPLETIONS   DURATION   AGE
job.batch/helloworld   1/1           2s         4m26s

$ kubectl describe job helloworld

Output:

lab_aa43f292201f@cloudshell:~ (lab-gcp)$ kubectl describe job helloworld
Name:           helloworld
Namespace:      default
Selector:       controller-uid=1e48440c-bdd3-11ea-85d1-42010a8000e4
Labels:         controller-uid=1e48440c-bdd3-11ea-85d1-42010a8000e4
               job-name=helloworld
Annotations:    <none>
Parallelism:    1
Completions:    1
Start Time:     Sat, 04 Jul 2020 14:48:23 +0600
Completed At:   Sat, 04 Jul 2020 14:48:25 +0600
Duration:       2s
Pods Statuses:  0 Running / 1 Succeeded / 0 Failed
Pod Template:
 Labels:  controller-uid=1e48440c-bdd3-11ea-85d1-42010a8000e4
          job-name=helloworld
 Containers:
  busybox:
   Image:      busybox
   Port:       <none>
   Host Port:  <none>
   Command:
     echo
     Hello Kubernetes!!!
   Environment:  <none>
   Mounts:       <none>
 Volumes:        <none>
Events:
 Type    Reason            Age    From            Message
 ----    ------            ----   ----            -------
 Normal  SuccessfulCreate  7m22s  job-controller  Created pod: helloworld-dfr2k

Finally, to delete hit

$ kubectl delete job helloworld

student_02_aa43f292201f@cloudshell:~ (labs-gcp-b17e65df)$ kubectl delete job helloworld
job.batch "helloworld" deleted

Congratulations

I hope we learn something exciting about gRPC framework. Thanks for time & passion. Feel free to ask me anything.

Say Hi to me on Twitter, Linkedin, and Medium where I keep on sharing interesting updates.

Install Nexus Repository Manager in Linux Centos7, Deploy and Use 'artifacts

Sadhan Sarker — Mon, 01 Aug 2022 10:58:00 +0000

Step 1: Login to your Linux server and update the yum packages. Also install required utilities.

yum update -y
sudo yum install wget -y
java -version
sudo yum install java-1.8.0-openjdk.x86_64 -y

Step 2: Download the latest nexus. You can get the latest download links fo for nexus from here.

cd /opt
sudo wget -O latest-unix.tar.gz https://download.sonatype.com/nexus/3/latest-unix.tar.gz
tar -xvzf latest-unix.tar.gz
sudo mv nexus-3* nexus
mv sonatype-work nexusdata
ls -lh

Step 3: Set User/Permissions and Configurations

useradd --system --no-create-home nexus
chown -R nexus:nexus /opt/nexus
chown -R nexus:nexus /opt/nexusdata

Edit /opt/nexus/bin/nexus.vmoptions file

vi /opt/nexus/bin/nexus.vmoptions

-Xms2703m
-Xmx2703m
-XX:MaxDirectMemorySize=2703m
-XX:+UnlockDiagnosticVMOptions
-XX:+LogVMOutput
-XX:LogFile=../nexusdata/nexus3/log/jvm.log
-XX:-OmitStackTraceInFastThrow
-Djava.net.preferIPv4Stack=true
-Dkaraf.home=.
-Dkaraf.base=.
-Dkaraf.etc=etc/karaf
-Djava.util.logging.config.file=etc/karaf/java.util.logging.properties
-Dkaraf.data=../nexusdata/nexus3
-Dkaraf.log=../nexusdata/nexus3/log
-Djava.io.tmpdir=../nexusdata/nexus3/tmp
-Dkaraf.startLocalConsole=false

Edit nexus.rc file.

vi /opt/nexus/bin/nexus.rc

Uncomment run_as_user parameter and add new value.

run_as_user="nexus"

We need to modify the nexus-default.properties file.

vi /opt/nexus/etc/nexus-default.properties

Change application-host=0.0.0.0 and port application-host=9081

Configure the open file limit of the nexus user.

vi /etc/security/limits.conf

Add the below values to the file.

nexus - nofile 65536

Step 4: Set Nexus as a System Service

Create the Systemd service file in /etc/systemd/system/.

sudo vi /etc/systemd/system/nexus.service

Add the following contents to the unit file.

[Unit]
Description=Nexus Service
After=syslog.target network.target

[Service]
Type=forking
LimitNOFILE=65536
ExecStart=/opt/nexus/bin/nexus start
ExecStop=/opt/nexus/bin/nexus stop
User=nexus
Group=nexus
Restart=on-failure

[Install]
WantedBy=multi-user.target

Manage Nexus Service, Execute the following command to add nexus service to boot.

systemctl daemon-reload
systemctl enable nexus.service
systemctl start nexus.service

Monitor the log file.

tail -f /opt/nexusdata/nexus3/log/nexus.log

Check the running service port.

netstat -tunlp | grep 9081

Show default login password.

cat /opt/nexusdata/nexus3/admin.password

Deploy and Use Artifacts in Spring Boot Project

Create or Edit this ~/.m2/settings.xml file:

vi ~/.m2/settings.xml

Update contents of the file.

<settings xmlns="http://maven.apache.org/SETTINGS/1.2.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/SETTINGS/1.2.0 http://maven.apache.org/xsd/settings-1.2.0.xsd">

  <!--  unblock so that we can download artifacts from nexus repo  -->
  <mirrors>
    <mirror>
      <id>maven-default-http-blocker</id>
      <mirrorOf>dummy</mirrorOf>
      <name>Dummy mirror to override default blocking mirror that blocks http</name>
      <url>http://0.0.0.0/</url>
    </mirror>
  </mirrors>


  <!--nexus server configuration-->
  <servers>
    <server>
      <id>nexus</id>
      <username>admin</username>
      <password>19e36q29-1e09-42ce-af29-4f74563a7467</password>
    </server>
  </servers>

</settings>

Deploy jar or artifact to nexus server

Now create a maven project. Open pom.xml file, and add this content inside project tag.

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">

  <!-- ...other  -->

  <!--  deploy libs to nexus repository -->
  <distributionManagement>
    <repository>
      <id>nexus</id>
      <url>http://119.168.0.0:9081/repository/sadhan</url>
      <!--<name>Nexus Releases</name>-->
    </repository>
    <snapshotRepository>
      <id>nexus</id>
      <url>http://119.168.0.0:9081/repository/sadhan</url>
      <!--<name>Nexus Snapshot</name>-->
    </snapshotRepository>
  </distributionManagement>

</project>

Now hit the following command to deploy jar to nexus repository.

mvn deploy        
mvn deploy -e        
mvn deploy -e release

mvn deploy -DaltDeploymentRepository=nexus::default::http://119.168.0.0:9081/repository/sadhan

Use and download jar/artifact from nexus server

Now pull the jar file from nexus repository.

Makes sure ~/.m2/setting.xml file copied properly.

Now open pom.xml file and add this upload dependency inside dependencies tag.

<dependency>
  <groupId>com.revesoft</groupId>
  <artifactId>olm</artifactId>
  <version>0.0.1</version>
</dependency>

Then add this below content inside project tag.

  <!--to use nexus repositories we need that -->
  <repositories>
    <repository>
      <id>nexus</id>
      <url>http://119.168.0.0:9081/repository/sadhan/</url>
      <!--<name>Nexus Releases</name>-->
    </repository>
  </repositories>

Using CLI, we can download the jar file from nexus repository.

mvn dependency:resolve -DremoteRepositories=nexus::default::http://119.168.0.0:9081/repository/sadhan

Note: Here id nexus is the same as in ~/.m2/settings.xml file. so use same it to download the jar file.

Optional

Upload blob file to nexus repository.

curl -v --user 'admin:admin123' --upload-file ./test.png http://localhost:9081/repository/documentation/test.png

Congratulations

I hope we learn something exciting about Nexus. Thanks for time & passion. Feel free to ask me anything.

Say Hi to me on Twitter, Linkedin, and Medium where I keep on sharing interesting updates.

References

https://help.sonatype.com/repomanager3/nexus-repository-administration/formats/maven-repositories

Up and Running with gRPC

Sadhan Sarker — Tue, 04 Jan 2022 05:00:18 +0000

Hello, Today I am going to talk about gRPC.

A high performance, open source universal RPC framework by google.

Now its part of the Cloud Foundation (CNCF)

Let's Understand RPC!

An RPC is a Remote Procedure Call. Google introduce gRPC, But Common Object Request Broker Architecture (CORBA) had RPC before!

In this above example, you see right side a server code written any other language and left client code calling server function. Okay, Lets consider server written in python we want to call this function from another language, what we will do we simply create a rest api then call that api using other language client. Now think 🤔 is not it cool? if we could call that function nativity like we call functions. I know that will be amazing using RPC we can do that easily.

Here is an another example from grpc.io website. You can see gRPC server code is written in C++, and gRPC Stubs Or Clients are written in different languages. Here as Stubs they are using Ruby and Java Android client. Do not worry I will share complete example end of the season.

When we choose gRPC?

When we wants to build microservices
Wants to communicate between cross-languages services
Planning to build distributed services
Needs client & server streaming
Needs Http/2 based transport protocol

gRPC vs REST

REST
REST uses HTTP/1.1 protocol through the JSON or XML messaging format. Common http verbs like {GET, POST, PUT, DELETE etc}

gRPC
gRPC uses HTTP/2 protocol through Protocol buffer. Methods {unary, server-streaming, client-streaming and bi-directional call}. It offers language independence support 11 programming languages.

gRPC methods/operations

What is Protocol Buffer

Protocol buffer are language language-neutral, platform-neutral extensible mechanism for serializing structured data
Code generated for any language
Very convenient for transporting a lot of data
Data is binary and efficiently serialized (small payloads)
Support Java, Go, Python, NodeJs, Objective-C, C++ and more with proto3 language version.

Sample gRPC Based Micro-service Architecture

Complete gRPC server & clients check that Demo Codebase

Congratulations

I hope we learn something exciting about gRPC framework. Thanks for time & passion. Feel free to ask me anything.

Say Hi to me on Twitter, Linkedin, and Medium where I keep on sharing interesting updates.

Securing cloud storage files with KMS

Sadhan Sarker — Sun, 05 Jul 2020 02:25:09 +0000

Cloud Key Management Service (KMS) allows us to create, import & manage cryptographic keys and also perform cryptographic operations in a single centralized cloud service the same way on-premises. By using Cloud KMS, Cloud HSM, or Cloud External Key Manager or Customer-Managed Encryption Keys (CMEK integrations) we can encrypt, decrypt, and verify.

In this post, we are going to deal with Cloud KMS, Cloud Storage, Cloud SDK. Also, learn about encryption and manage encryption keys using KMS. So, let’s a drive-in. Sign-in to Google Cloud Platform (GCP) Console and Create a new project and activate our Cloud Shell.

Click Continue

Create a Cloud Storage Bucket

Create Cloud Storage Bucket, we can do that using gsutil, remember bucket names are globally unique. Run the following command in Cloud Shell to set a variable to our bucket name:

export CLOUD_STORAGE_BUCKET_NAME=put_our_unique_bucket_name

Now, just hit the following command, to create a new cloud storage bucket,

gsutil mb gs://${CLOUD_STORAGE_BUCKET_NAME}

Create a sample data

Create a simple file so that we can encrypt & decrypt that file, Open Cloud Shell and create a new file, Here, I’m using Vim console-based text editor. If we want, we can download the source file from another location. To create a new file, run the following command:

vi hello.txt

Input: to insert content press i,

Hello! From Cloud Storage KMS. We are going to encrypt and decrypt this file using Cloud KMS.

Note: To save that hello.txt file press Ctrl+c and type :wq . To read that file content hit below commands,

cat hello.txt

Output:

Hello! From Cloud Storage KMS. We are going to encrypt and decrypt this file using Cloud KMS.

Enable Cloud KMS Service

Before using Cloud KMS, we must need to enable that service. It could be done from Cloud Console UI and another is from gcloud CLI command. To enable the Cloud KMS Service, run the following command in our Cloud Shell:

gcloud services enable cloudkms.googleapis.com

Optional, this only needs to be done once per project

gcloud services enable cloudkms.googleapis.com \
    --project "${GOOGLE_CLOUD_PROJECT}"

Create KeyRing and CryptoKey

In order to encrypt & decrypt data, we need to create a KeyRing and a CryptoKey. KeyRings are useful for Grouping keys. To create KeyRing for a global region:

gcloud kms keyrings create "our-keyring" --location "global"

Note: If we want to view that newly created key then Open Web UI.

Next, using the new KeyRing, create a CryptoKey

gcloud kms keys create "our-cryptokey" \
    --location "global" \
    --keyring "our-keyring" \
    --purpose "encryption"

From Web UI We can view that Keys,

Click on our-keyring then we are able to see our-cryptokey, which is group together

Encrypt our file

Encrypt the hello.txt file contents using Cloud KMS. Here, I’m using the gcloud command-line tool. But we can also encrypt data using the Cloud KMS API.

gcloud kms encrypt --location "global" \
    --keyring "our-keyring" --key "our-cryptokey" \
    --plaintext-file ./hello.txt \
    --ciphertext-file ./hello.enc

This will create a hello.enc file which will be encrypted. To open that encrypt file run:

cat hello.enc

Output: Cloud be like an unreadable hash like “6B!h>X7^RR*IRt;_*b~0IrP1<)]'ǞЉt c”

Now, we can upload that encrypted file to the Cloud Storage, run the following command

gsutil cp ./hello.enc gs://${CLOUD_STORAGE_BUCKET_NAME}

We can view our encrypted file which actually uploaded,

Decrypt our file

If we want to decrypt that hello.enc. Or, we have already encrypted data then we can copy that from Cloud Storage bucket by the following command,

gsutil cp gs://${CLOUD_STORAGE_BUCKET_NAME}/hello.enc .

Note: In this case, we don’t have to do that because we already have our hello.enc file.

Now, We can decrypt that file by the following command below,

gcloud kms decrypt --location "global" \
    --keyring "our-keyring" --key "our-cryptokey" \
    --ciphertext-file ./hello.enc \
    --plaintext-file ./hello-decryped.txt

To open that hello-decryped.txt file run following command

cat hello-decryped.txt

Output:

Hello! From Cloud Storage KMS. We are going to encrypt and decrypt this file using Cloud KMS.

Cleanup environment

To delete cloud storage bucket, which we created earlier, run the following command

gsutil rm -r gs://${CLOUD_STORAGE_BUCKET_NAME}

Note: Cloud KMS resources can’t be deleted. However, we can destroy that by the following command

gcloud kms keys versions destroy "1" \
    --location "global" \
    --key "our-cryptokey" \
    --keyring "our-keyring"

Congratulations

We have successfully encrypted and decrypt data using Cloud KMS and stored encrypted data in Cloud Storage. Thanks for time & passion. Feel free to ask me anything.

Say Hi to me on Twitter, Linkedin, and Medium where I keep on sharing interesting updates.

Original Post

Journey to Google Cloud Platform (GCP)

Sadhan Sarker — Tue, 23 Jun 2020 00:50:44 +0000

🔰 Overview

Most of us are heard about Amazon Web Services(AWS) and Microsoft Azure, Google Cloud Platform (GCP), and other Cloud Providers. From experience, I found all the cloud providers are offering really competitive services.

AWS, Azure has a higher market share and popularity rather than GCP. But practically, It's always not necessary to choose one Cloud base on popularity. It depends on the needs. Sometimes, It could be wisher decisions so providers not act like monopolistic. Cloud provider gives us the ability to make a hybrid cloud, I think that will be another cool option. Today let's make a visit about Google Cloud Platform (GCP)

🔰 About Google Cloud Platform

I found Google Cloud is very Developer focused. Google has site reliability engineers (SREs), not only Operations people to manage their services. Generally, I feel GCP built from Dev. sides rather than operations or infrastructure. Other hand AWS built from ops or infra sides rather Dev. GCP feels me Coding first then the tools come later, Other AWS feels DevOps cloud.

Google is all about Big Data. They have Smart Googlers they develop lots of internal innovation. They published many white-papers and released things as Open source like Kubernetes (K8s). Also, they Commercialized their own used services like BigTable, Spanner, GCS, BigQuery, etc. AWS is a more regional basic service, on the other hand Google is intrinsically global.

I just try to put some constructive view, Other cloud providers give us the ability, but we need to implement those by own.

🔰 GCP offering me what? I have no idea about the Cloud!

I'm going to introduce something really helpful and handle to start. I would like to give a short reference so that anyone can start with GCP. Sometimes we need a high-level overview so that we can deep dive into it. It's not about expert or beginner, sometime overview and references help to memorize something in an organized way. You know we all are human so it's really hard to memories everything once. I would like to recommend don't try to memorize everything at a time. When you will have done hands-on later it automatically remembers. Here are those references,

Image Source | If wants to look further, in details about GCP Products & Services.

If some products and services are complex to understand then don't worry about that cause do not need to expertise on everything at a time. You have to pay for services as needed, you save money and can focus on innovation.

🔰 How much it cost? I'm not going to invest money in that!

Yes, it's really important to thought. As a beginner or expert both have different perspectives on that topic. GCP offers,

Let me talk first about the beginner. They would like to explore GCP products so they deploy sample applications and play around on it. Once they get skilled, Students, startups, and individual developers deploy their first innovative application. And it's readiest for production with high availability, reliability, and scalability. So that they can serve their client globally. Other hands, Experts & professionals like to simulate their products and like to integrate third-party services. They might use other providers like AWS or Azure, so now they looking for something else that could GCP offers. Which gives them business value. For that reason, GCP offers Google Cloud Free Tier. I will talk about it later in details, Additional, you can take a look at GCP pricing

🔰 I would like to Explore the Google Cloud Platform!

For that reason, they offer GCP Free Trial. It does not get charged for the billing account. We only need a credit card, for verification. Don't worry, later it must have to manually upgraded for a paying account. I will be a great option who want to learn and explore GCP. When you create a free trial account on GCP you also get $300 USD credit that you can use up to 12 months. If you used up to $300 USD over. Then you're existing one will be paused and it offers you for a paid account upgrade. Additionally, It only allows for individuals and has some restrictions, remembers business accounts are not eligible for the free trial. Open a Free Trial Account.

Keep learning and Exploring. Coding is fun 😎.

👌 Thanks for your time & passion. Feel free to ask me anything.

Say Hi to me on Twitter and Linkedin where I keep on sharing interesting updates.

References

Unix File Symbolic Permission

Sadhan Sarker — Fri, 19 Jun 2020 09:41:49 +0000

I'm trying to introduce how can we change the permission using symbolic permission, another way is numeric permission. Just open up Unix Terminal and then explore those commands.

👌 Thanks for your time & passion.
Feel free to comments, If you have any issues & queries.

Feel free to ask me anything and Follow me on Twitter

Vi (Vim) Text base editor regular commands

Sadhan Sarker — Wed, 17 Jun 2020 18:48:01 +0000

Vi (Vim) Text base editor regular commands. Should be used to, on these commands. It will save you life.

👌 Thanks for your time & passion. Feel free to ask me anything.
If you have any issues & queries. Follow me on Twitter

Let's Look at Networking Modes

Sadhan Sarker — Wed, 17 Jun 2020 16:38:20 +0000

Many of us, confused about Networking Modes. I hope this will helps you to understand.

👌 Thanks for your time & passion. Feel free to ask me anything.
If you have any issues & queries. Follow me on Twitter

The Complete Dev. Startup Organization Setup with GitHub

Sadhan Sarker — Sun, 17 May 2020 12:28:39 +0000

I found complete startups organization management solution with GitHub. As a startup Software development & technology team, we need to consider lots of things like project source code management, do teamwork, teams and build packages maintainability. In here we can configure everything in the same place. Finally, last but not last everything is free. 😇

🔰 1. Open an Organization

Open this Url https://github.com/organizations/plan . Pick a Plan that suitable for the organization. Here we choose a free plan.

Choose Plan:

Free Plan Registration Page:

In here nothing complex just put organizational information like what will be organizational account name, contact email address and finally organizational type.

Note: Don't worry the information will be changeable in future.

After hit next we are able to get a welcome page like below, we don't need to invite everyone now, we can add them later to do so hit Skip the step.

Welcome and Users Invitation Page:

Congratulation Here, we have a homepage of our organization. we need to configure a couple of things we will make it later.

Welcome and Home Page:

🔰 2. Organization Settings

Select the Settings tab and we have setting information. We can update easily require information. That information is related to the organization. So filling that information we can globally tell about an organization. It is pretty simple to configure.

Here is Setting page:

🔰 3. Projects Management

Now choose the Projects tab. This is a great window where we can find out which projects are going on about their metrics and more about project backlog related stuff.

Here is Project page:

🔰 4. Teams Management

Now choose Teams Tab. In this simple window, we are able to control different teams. We can create invite our team members. we can also discuss and collaborate in an individual team or Whole organization. It's is cool stuff?. Team communication and collaboration is easy.

Here is our teams page:

🔰 5. People Management - Do Administrative Stuff.

Now choose People Tab. In this page all the people are visible, We can do the administrative task from here. Here we can change and permit user ownership and roles So that we can do the different level of organizational administrative job.

Here is peoples management page:

🔰 6. Packages Management

Now choose Packages Management. Github came with great feature. Now we can easily manage packages, binaries and build we can easily upload our common reusable packages and use them into projects. Not need to go for an external solution. Now Everything in on the same place.

Note: It has some pricing related issue, so check before using it.

Here is package management page:

🔰 7. Create a New Repository

Hit Create Repository. As like as GitHub personal user account, Now we can create a personal organizational repository, It can be Public/Private.

Here is - Package Management Page:

Here is - New Repository Creation Page:

🔰 8. How to Publish Project Source Code

This is an Empty Repository Page. We can follow their guidelines, But before doing that we need to set up Git client So that we can execute those commands. Else if we have an existing project already then we can just simply upload it using drag and drop by selecting upload and existing file blue link. But the command line is recommended and very convenient to do this. Once we are hands-on by dirty our hand, it will be really fun.

Here is - Empty Repository Page:

https://dev-to-uploads.s3.amazonaws.com/i/1y0r0ms765y1d9kg5ydl.png

🔰 9. Learn More about Git & Commands

📗 First Time Git Configuration

Before you can start using Git, you need to configure it. Run each of the following lines on the command line to make sure everything is set up.

🕹 Sets up Git with your name

git config --global user.name "<Your-Full-Name>"

🕹 Sets up Git with your email

git config --global user.email "<your-email-address>"

📗 The seven rules of a great Git commit message

Keep in mind: This has all been said before.

Separate subject from the body with a blank line
Limit the subject line to 50 characters
Capitalize the subject line
Do not end the subject line with a period
Use the imperative mood in the subject line
Wrap the body at 72 characters
Use the body to explain what and why vs. how

For example:

Summarize changes in around 50 characters or less

More detailed explanatory text, if necessary. Wrap it to about 72
characters or so. In some contexts, the first line is treated as the
subject of the commit and the rest of the text as the body. The
blank line separating the summary from the body is critical (unless
you omit the body entirely); various tools like `log`, `shortlog`
and `rebase` can get confused if you run the two together.

Explain the problem that this commit is solving. Focus on why you
are making this change as opposed to how (the code explains that).
Are there side effects or other unintuitive consequences of this
change? Here's the place to explain them.

Further paragraphs come after blank lines.

 - Bullet points are okay, too

 - Typically a hyphen or asterisk is used for the bullet, preceded
   by a single space, with blank lines in between, but conventions
   vary here

If you use an issue tracker, put references to them at the bottom,
like this:

Resolves: #123
See also: #456, #789

Note: we can add multiple line commit using git commit command

📗 Branching, Merging and Tagging

The git branch is a very important concept. It becomes really helpful when project co-workers are frequently working on new features development. Also, It makes the project more maintainable & integrable. If we want to contribute on any Open Source project then we need branch.

The git branch command is used to interact with Git's branches:

git branch

It can be used to:

list all branch names in the repository
create new branches
delete branches

🕹 Create Branch

git branch latest
git branch footer-fix

🕹 Switch Back and forth to different Branch.
To navigate into different branches using git checkout

 git checkout footer-fix
 git checkout -b header-fix

Note: git checkout -b header-fix create a new branch and make it Active Branch in the code editor.

🕹 Delete Branch

git branch -d footer-fix

🕹 See All Branches At Once

git log --oneline --decorate --graph --all

🕹 Undo from selected Branch

# undo once, from commits
git reset --hard HEAD^
git reset --hard master^

git reset --hard HEAD^

# undo twice, from commits
git reset --hard HEAD^^

🕹 Merge into different Branch

git merge <name-of-branch-to-merge-in-[Eg.footer-fix]>

Note: Active branch merge with given <name-of-branch-to-merge-in>

🕹 Syncs all the available remote branches

git fetch

🕹 Push update or changes using

git push origin master
git push origin footer-fix

📗 Merge Conflict

When multiple teams and peoples are working on a single file or branch at the same time then merging conflict occurs. To avoid these types of occurrence, we need to avoid working on the same file & branch at the same time.

🕹 Merge Conflict Indicators Explanation
The editor has the following merge conflict indicators:

<<<<<<< HEAD everything below this line (until the next indicator) shows you what's on the current branch
||||||| merged common ancestors everything below this line (until the next indicator) shows you what the original lines were
======= is the end of the original lines, everything that follows (until the next indicator) is what's on the branch that's being merged in
>>>>>>> heading-update is the ending indicator of what's on the branch that's being merged in (in this case, the heading-update branch)

🕹 Resolving A Merge Conflict

Git is using the merge conflict indicators to show you what lines caused the merge conflict on the two different branches as well as what the original line used to have. So to resolve a merge conflict, you need to:

choose which line(s) to keep
remove all lines with indicators

Notes: finally make new commit after resolve it manually.

📗 Undoing Changes

🕹 Git reset or revert local changes until commit

$ git checkout .

🕹 Changing The Last Commit

With the --amend flag, you can alter the most-recent commit.
like, Add Forgotten Files To Commit

git commit --amend

📗 The git revert Command

Now that I've made a commit with some changes, I can revert it with the git revert command

git log
git revert <SHA-of-commit-id-to-revert>

This command:

SHA-of-commit-id-to-revert will be founded by git log
will undo the changes that were made by the provided commit
creates a new commit to record the change

🕹 Change remote origin

$ git remote set-url origin https://github.com/mesadhan/sample-app.git

🕹 Remote origin status

$ git remote -v

📗 Relative Commit References for Back and forth

Sometimes we back

^ – indicates the parent commit
~ – indicates the first parent commit

Here's how we can refer to previous commits:

The parent commit – the following indicate the parent commit of the current commit

HEAD^
HEAD~
HEAD~1

The grandparent commit – the following indicate the grandparent commit of the current commit

HEAD^^
HEAD~2

The great-grandparent commit – the following indicate the great-grandparent commit of the current commit

HEAD^^^
HEAD~3

📗 Remove Local and Remote Commit

To view commits history base on the number hit below command,

$ git rebase -i HEAD~2

Now Remove those commit from the list and save.

Optional, You can pull, if you want to sync with the latest work then below command,

$ git pull

Otherwise, permanently change your local and remote repository using below command,

$ git push origin master

Note: Here, git rebase -i HEAD~2, will show last two commits. we can change the number for more commit history.

📗 Git Tag Command

Git tag uses usually when we release a version for a product. It is important to know how we can tag annotations,

🕹 add a tag with annotation and version

git tag -a v1.0
git tag -a beta

Sample Tag Commit message

Put Headline About Tag
#
# Write a message for tag:
#   v1.0
# Lines starting with `#` will be ignored

CAREFUL: In the command above (git tag -a v1.0) the -a flag is used. This flag tells Git to create an annotated flag. If you don't provide the flag (i.e. git tag v1.0) then it'll create what's called a lightweight tag.

Annotated tags are recommended because they include a lot of extra information such as:

the person who made the tag
the date the tag was made
a message for the tag

Because of this, you should always use annotated tags.

🕹 Verify Tag & Tag History

After saving and quitting the editor, nothing is displayed on the command line. So how do we know that a tag was actually added to the project? If you type out just git tag, it will display all tags that are in the repository.

git tag
git log --decorate

🕹 Deleting A Tag

git tag -d v1.0
git tag --delete v1.0

👌 Thanks for your time & passion. Feel free to ask me anything.
If you have any issues & queries. Follow me on Twitter

🔰 References:-

Upload & takes control over the Youtube Data API

Sadhan Sarker — Mon, 27 Apr 2020 08:55:03 +0000

Using Youtube Data API we can access YouTube features to our application, including the ability to upload videos, create and manage playlists, and more.

As a Developer, we need to handle third party API or custom own API. There is no developer who is not integrated any single API in her development journey. So let me introduce API with you. What is actually API is. API is basically Application Programming Interfaces.

🔰 Bit of information about API

If I make it simple then it's a common guideline, which way two software can talk to each other. Let’s break,

-📗 Application:- is a service app or could be a third-party open data portal. (Eg. Youtube, Google Map, etc)
-📗 Interface:- It's like a medium, which has some common definitions or formats. (Eg. JSON, XML or Other light-weight file format). JSON is a common and widely used format.
-📗 And finally, Program:- is a set of codes that the developer writes to develop the application. (Eg. Youtube Data API Codes)

I hope you guys get an idea about API if you want to know more about it. Then look below references.

🔰 Setting up your API-Key or Pre-configuration.

As I mentioned two systems talk to each other. So one issue raises, that is Security! so that we can take over the control of application resources. API's could be open or close via API-key. We need to configure API-key for close application resources. Okay, let's setup api-key for Youtube Data API.

🔰 Setup Youtube Data API Congifuraiton

-[1] Visit, and Enable Youtube Data API
-[2] If not exist then Create New Project
-[3] Search For API Youtube Data API, Enable It.
-[4] Then Left Menu Click Credentials.
-[5] Create API Keys, Select none then Restrict key radio and choose Youtube Data API from Dropdown.
-[6] And Finally, From Credentials create OAuth 2.0 Client IDs with Authorized JavaScript origins Urls [http://localhost] and [http://localhost:5000] or [https://custom-appserver-domain.com]
-[7] Replace js/YoutubeDataApi.js file CLIENT_KEY and API_KEY.
-[8] Now run the app using live server or deploy its production server. [I used VScode life server Extension]

Note: Origins must me match as defined as OAuth2.0 client console.
Details guide will be found. Guide. Else Occurre authentication-related error.

🔰 I have attached a demo sample source code below,

Sample Project Source Code

🔰 Finally, Run & Test Application

-📗 Clone Project from GitHub and then move on
-📗 After run application using live server
-📗 Login with Gmail account and accept require permission
-📗 Finally, Navigate Button and test.

I'm sorry I can't get enough time to optimize its example code. If anyone interested to work with this project then feels free to knock me. I came to share this example because I didn't found any complete tutorial on it. So I think it might be helpful for others.

👌 Congratulations. & Thanks for your time & passion. Feel free to comments, If you have any issues & queries. Follow me on Twitter

🔰 References:

OpenShift Origin 3.11 (OKD) Installation on a CentOS 7 Multi-Node Cluster

Sadhan Sarker — Tue, 31 Mar 2020 07:51:59 +0000

Overview

OpenShift Origin (OKD) is the Community Distribution of Kubernetes that powers Red Hat OpenShift. Built around a core of OCI container packaging and Kubernetes container cluster management, OKD is also augmented by application lifecycle management functionality and DevOps tooling. OKD provides a complete open-source container application platform

🔰1. Prerequisites

We can plan to install 3 physical machines or VM, and they should be connected on the Internet

Distribution: Centos 7 linux [Os Minimal Installation]
IP Address: 192.168.31.182 with 8 GB, 2 Core
IP Address: 192.168.31.144 with 4 GB RAM, 2 Core
IP Address: 192.168.31.94 with 4 GB RAM, 2 Core

Login username: root
Password: 123456

Note: Mentioned ip address and credential uses just for references. Please take a look at Official prerequisites

🔰2. To access remotely through username & password, needs to Installing and Enabling OpenSSH

📗 Install OpenSSH & net-tools packages, start and show status of SSH service, run automatic after reboot and finally show machine IP Address.

yum –y install openssh-server openssh-clients net-tools

systemctl start sshd
systemctl status sshd
systemctl enable sshd
ifconfig

Note: Now we can able to access those services through Terminal or Putty

🔰3. Common steps for on all the machines or nodes [Here, Master, Compute, Infra], Login into each single machine

📗 Step1: Install base packages

yum install -y wget git zile net-tools bind-utils iptables-services bridge-utils bash-completion kexec-tools sos psacct openssl-devel httpd-tools python-cryptography python2-pip python-devel python-passlib java-1.8.0-openjdk-headless "@Development Tools"
yum update -y

yum install docker-1.13.1
systemctl start docker && systemctl enable docker && systemctl status docker

yum -y install https://dl.fedoraproject.org/pub/epel/epel-release-latest-7.noarch.rpm
sed -i -e "s/^enabled=1/enabled=0/" /etc/yum.repos.d/epel.repo

📗 Step2: Set hosts for all nodes, so future ansible can communicate with all machines for automation

Open that file and vi /etc/hosts, include contents

192.168.31.182  master.192.168.31.182.nip.io
192.168.31.144  compute.192.168.31.144.nip.io
192.168.31.94  infra.192.168.31.94.nip.io

Now, restart network service

service network restart

📗 Step3: Login into each single machine and set hostname for all nodes

hostnamectl set-hostname hostname.<machine-ip>.nip.io

Examples for all machine:

hostnamectl set-hostname master.192.168.31.182.nip.io
hostnamectl set-hostname compute.192.168.31.144.nip.io
hostnamectl set-hostname infra.192.168.31.94.nip.io

Note: Remember each machine has only one hostname, so don't put all hostname in a single machine.

📗 Step4: Modify '/etc/NetworkManager/NetworkManager.conf' so after reboot wifi-router each time, DNS shouldn't change.

open this file vi /etc/NetworkManager/NetworkManager.conf, include contents

[main]
#plugins=ifcfg-rh,ibft
dns=none

📗 Step5: Modify ifconfig label information, and use google DNS

ifconfig
cd /etc/sysconfig/network-scripts

In Here, mine label was ifcfg-ens33, so vi ifcfg-ens33 and include contents

PEERDNS="no"
DNS1="8.8.8.8"

📗 Step6: Modify resolv.conf file, to update nameserver & search globally

open vi /etc/resolv.conf, include contents

search nip.io
nameserver 8.8.8.8

📗 Step7: Restart network manager & network service

systemctl restart NetworkManager
service network restart

📗 Step8: Change Selinux setting on Master,Compute,Infra

open vi /etc/selinux/config, include contents

SELINUX=enforcing
SELINUXTYPE=targeted

📗 Step9: Reboot machine

reboot

Note: For unknown behaviors, we can restart network manager & service

🔰4. Finally, log in into Master Machine and follow the below instructions,

📗 Step1: create ssh key and copy public key to other machines or nodes, fso we can communicate without username and password. It's needed for SSH.

ssh-keygen

for host in master.192.168.31.182.nip.io \
master.192.168.31.182.nip.io \
compute.192.168.31.144.nip.io \
infra.192.168.31.94.nip.io; \
do ssh-copy-id -i ~/.ssh/id_rsa.pub $host;
done

📗 Step2: After boot all the machines, we can ping from an external machine terminal or command

ping google.com
ping master.192.168.31.182.nip.io
ping compute.192.168.31.144.nip.io
ping infra.192.168.31.94.nip.io

Notes:

ping VM to VM = Ok
ping Host to VM = Ok
ping www.google.com = Ok

📗 Step3: install ansible 2.7 in master node

rpm -Uvh https://releases.ansible.com/ansible/rpm/release/epel-7-x86_64/ansible-2.7.10-1.el7.ans.noarch.rpm
ansible --version

📗 Step4: Now, clone openshift-ansible repository, and switch 3.11 release branch

git clone https://github.com/openshift/openshift-ansible.git
cd openshift-ansible && git fetch && git checkout release-3.11

📗 Step5: Create ansible hosts.ini configuration,

# Create an OSEv3 group that contains the masters, nodes, and etcd groups
[OSEv3:children]
masters
nodes
etcd

# Set variables common for all OSEv3 hosts
[OSEv3:vars]
# SSH user, this user should allow ssh based auth without requiring a password
ansible_ssh_user=root
# If ansible_ssh_user is not root, ansible_become must be set to true
ansible_become=true
openshift_master_default_subdomain=app.192.168.31.94.nip.io
deployment_type=origin

[nodes:vars]
openshift_disable_check=disk_availability,memory_availability,docker_storage
[masters:vars]
openshift_disable_check=disk_availability,memory_availability,docker_storage
# uncomment the following to enable htpasswd authentication; defaults to DenyAllPasswordIdentityProvider
openshift_master_identity_providers=[{'name': 'htpasswd_auth', 'login': 'true', 'challenge': 'true', 'kind': 'HTPasswdPasswordIdentityProvider'}]

# host group for masters
[masters]
192.168.31.182

# host group for etcd
[etcd]
192.168.31.182

# host group for nodes, includes region info
[nodes]
192.168.31.182  openshift_node_group_name='node-config-master'
192.168.31.144  openshift_node_group_name='node-config-compute'
192.168.31.94  openshift_node_group_name='node-config-infra'

📗 Step5: Execute ansible playbooks with hosts.ini configuration,

ansible-playbook -i hosts.ini playbooks/prerequisites.yml
ansible-playbook -i hosts.ini playbooks/deploy_cluster.yml

Note: If you're prerequisites.yml not throw any error, then you can ready for deploy_cluster.yml. After hours of later, you can able to see this screen. I hope your face will be glowing like mine! 🤩

📗 Step6: Create Admin User, so that we can log in to web console, we can also able to see web console URL

htpasswd -c /etc/origin/master/htpasswd admin
oc status

Note: We already created admin users, so use those credentials to move forward.

After 5 hours (depends on internet speed and nodes resources), successfully able to install a private cloud on an open-source container application platform using centos 7 with 3 nodes. It's lots of fun. It might occur errors if you're network connection is poor and machines or nodes resources (CPU, RAM) are not properly.

👌 Congratulations. & Thanks for your time & passion.
Feel free to comments, If you have any issues & queries.

🔰 References:

Manage Your're Mail Using IMAP

Sadhan Sarker — Mon, 02 Mar 2020 07:19:22 +0000

📗 IMAP Overview

If you have ever set up an email client or app, you will have certainly come across the terms POP and IMAP.
IMAP-is short for Internet Message Access Protocol, while POP-translates to Post Office Protocol. In other words, both are email protocols. You might listen about Outlook, Thunderbird, Eudora, GNUMail, or (Mac) Mail app which provides custom mail management services they download messages from your email account and to make changes like archiving messages or sorting them into folders and giving more personalization.

Essentially, the main difference of the two protocols is that POP downloads emails from the server for permanent local storage, while IMAP leaves them on the server and just caches (temporarily stores) emails locally. In other words, IMAP is a form of cloud storage.

📗 When Choose POP:-

if you want to access your mail from only one single device.
if need constant access to your email, regardless of internet availability.
if you have limited server storage.

📗 When Choose IMAP:-

if want to access your email from multiple different devices.
if you have a reliable and constant internet connection.
if you want to receive a quick overview of new emails or emails on the server.
if local storage space is limited.
if worried about backing your emails up.

If confused, then go with IMAP. It’s the more modern protocol, it allows you to be flexible, and your email is automatically backed up on the server.

Today, we're going to look into IMAP, It's the open standard that describes how to access messages in an email mailbox. While we want to read and send mail programmatically, then IMAP is important. we just need an IMAP client with implemented on top of IMAP protocol standards.

Now let's deep dive into it. We’re going to connect to an email account, list all of the available folders in the mailbox, and download a message. Here, we are going to use NodeJS IMAP Client which will help us to explore,

📗 Enable IMAP permission for your E-Mail

Log in your Gmail then, Open Email Setting, then Select Forwarding and POP/IMAP tab and change the status to IMAP access: Status: IMAP is enabled. To do so Select Enable IMAP. After login into Gmail, Click Dynamic Link For Quick Access.
Now enable Less Secure Apps: ON. To do After login into Gmail, Click Dynamic Link For Quick Access.

🔰 Now, Setup IMAP Client

Here, I'm using nodejs client but you can use other language clients to achieve those features,

Before creating a node application make sure node is installed in your machine, You can find the installation guide from here [https://nodejs.org/en/download/].

node --version
npm --version

🔰Create a node application,

mkdir imap-client-app
npm init -y
npm install --save imap

Note: NodeJs library Node-IMAP Client at Github.

📗 Take a look at implementation,

🔰 Now, create manage-mailbox.js files

const Imap = require('imap'), inspect = require('util').inspect;


let getEmailFromInbox = (mailServer) => {
    mailServer.openBox('INBOX', true, function (err, box) {
        if (err) throw err;
        // we can define range '1:3'
        let f = mailServer.seq.fetch('1:*', {
            bodies: 'HEADER.FIELDS (FROM TO SUBJECT DATE)',
            struct: true
        });
        f.on('message', function (msg, seqno) {
            console.log('Message #%d', seqno);
            let prefix = '(#' + seqno + ') ';
            msg.on('body', function (stream, info) {
                let buffer = '';
                stream.on('data', function (chunk) {
                    buffer += chunk.toString('utf8');
                });
                stream.once('end', function () {
                    console.log(prefix + 'Parsed header: %s', inspect(Imap.parseHeader(buffer)));
                });
            });
        });
        f.once('error', function (err) {
            console.log('Fetch error: ' + err);
        });
        f.once('end', function () {
            console.log('Done fetching all messages!');
            //mailServer.end();
        });
    });
}

let createLabel = (mailServer, labelName) => {
    mailServer.addBox(labelName, (err) => {});
    console.log('message', 'New Label or Box Created');
}

let getMailboxStatusByName = (mailServer, inboxName) => {
    mailServer.status(inboxName, (err, mailbox) => {
        console.log('message', mailbox);
    });
    console.log('message', 'Label or Box Status');
}

let getMailBoxLabels = (mailServer) => {
    mailServer.getBoxes((error, mailbox) => {
        console.log('message', mailbox);
    })
}

let deleteLabel = (mailServer, labelName) => {
    mailServer.delBox(labelName, (error) => {})
   console.log('message', 'Label or Box removed');
}

let mailServer1 = new Imap({
    user: 'example@gmail.com',
    password: 'password',
    host: 'imap.gmail.com',
    port: 993,
    tls: true,
    tlsOptions: {
        rejectUnauthorized: false
    },
    authTimeout: 3000
}).once('error', function (err) {
    console.log('Source Server Error:- ', err);
});
mailServer1.once('ready', function () {
    mailServer1.openBox('INBOX', true, function (err, box) {
        if (err) throw err;
        console.log('message', 'server1 ready');
    });

    // mail operation
    getMailBoxLabels(mailServer1);
    getEmailFromInbox(mailServer1)
    createLabel(mailServer1, "demo-label1");
    deleteLabel(mailServer1, "demo-label1");
    getMailboxStatusByName(mailServer1, "INBOX");
})
mailServer1.connect();

🔰 To run that script, hit below command, see output

node manage-mailbox.js

🔰 We can import and export email, one email server to another email server. To copy email create copy-mailbox.js,

const Imap = require('imap'), inspect = require('util').inspect;

// Here, copy email source-mail-server to target-mail-server
let copyEmail = (srcServer1, srcServer2, emailServerName) => {
    srcServer1.search(['ALL'], (error, uids) => {
        //console.log('message', uids);
        var count = uids.length;
        var f = srcServer1.fetch(uids, { bodies: 'HEADER.FIELDS (FROM TO SUBJECT DATE)', struct: true });

        f.on('message', function (msg, seqno) {
            //console.log('Got a message with seq no: ' + seqno);

            var buffer = [], bufLen = 0, bufferText = '';
            msg.on('body', function (stream, info) {
                stream.on('data', function (chunk) {
                    bufferText += chunk.toString('utf8');
                    buffer.push(chunk);
                    bufLen += chunk.length;
                });
                stream.once('end', function () {
                    console.log('Parsed header: %s', inspect(Imap.parseHeader(bufferText)));                  // email contents
                    console.log(`====${emailServerName} - Finished message no. ${seqno} =======`);            // email email seqno

                    //console.log('message-binay-buffer', buffer);
                    //console.log('message-bufLen', bufLen);
                    //console.log('message-total-email-count', count);

                    buffer = Buffer.concat(buffer, bufLen);
                    srcServer2.append(buffer, {
                        date: new Date(msg.date),
                        flags: ['Seen']
                    }, function (err) {
                        if (err) throw err;
                        if (--count === 0) {
                            console.log('Done copying!');
                            srcServer2.end()                    // close mail server1 connection
                            srcServer1.end()                    // close mail server2 connection
                        }
                    });

                });
            });
        });
        f.once('error', function (err) {
            console.log('Fetch error: ' + err);
        });
        f.once('end', function () {
            console.log('Done fetching all messages!');
        });
    });
};

let srcServer2 = new Imap({
    user: 'example-target@gmail.com',
    password: 'password',
    host: 'imap.gmail.com',
    port: 993,
    tls: true,
    tlsOptions: {
        rejectUnauthorized: false
    },
    authTimeout: 3000
}).once('error', function (err) {
    console.log('Target mail server error:- ', err);
});

srcServer2.once('ready', function () {
    srcServer2.openBox('INBOX', true, function (err, box) {
        if (err) throw err;
        console.log('message', 'Target mail server ready');
        let srcServer1 = new Imap({
            user: 'example-source@gmail.com',
            password: 'password',
            host: 'imap.gmail.com',
            port: 993,
            tls: true,
            tlsOptions: {
                rejectUnauthorized: false
            },
            authTimeout: 3000
        }).once('error', function (err) {
            console.log('Source Server Error:- ', err);
        });
        srcServer1.once('ready', function () {
            srcServer1.openBox('INBOX', true, function (err, box) {
                if (err) throw err;
                console.log('message', 'Source mail server ready');

                copyEmail(srcServer1, srcServer2, 'Server1');
            })
        });
        srcServer1.connect();
    });
})
srcServer2.connect();

🔰 To run that script, hit below command, see the output

node copy-mailbox.js

We’ve done it! you’ve learned major components of IMAP. We connected to an IMAP server, logged in to our email account, listed folders on the remote server, and downloaded message data, create a label, list of mail count. This is exactly what happens under the hood in email apps as you browse your mailbox.

📗 Bonus Section

🔰 Read Unseen email and update flag.

If, we like to parse email, use Mailparser. which is an advanced email parser for Node.js. Install package from here [https://nodemailer.com/extras/mailparser/]

npm install mailparser --save

// false = read only mood off, so after fetch we can update flag.
server.openBox('INBOX', false, function (err, box) {
    if (err) throw err;
    server.search(['UNSEEN'], function (err, results) {

        let f = server.fetch(results, {bodies: ''});
        const simpleParser = require('mailparser').simpleParser;

        f.on('message', function (msg, seqno) {
            let uid, headers, body = '';
            msg.on('body', function (stream, info) {
                simpleParser(stream, (err, parsed) => {
                    console.log(parsed.text)
                    console.log(parsed.textAsHtml)
                });
            });
            msg.once('attributes', function (attrs) {
                uid = attrs.uid;
                console.log(attrs);
            });
        });

        f.once("error", function (err) {
            return Promise.reject(err);
        });
    });
});

👌 Congratulations. & Thanks for your time & passion.
Feel free to comments, If you have any issues & queries.

Forem: Sadhan Sarker

Monitoring Cronjobs in GKE

Congratulations

Install Nexus Repository Manager in Linux Centos7, Deploy and Use 'artifacts

Deploy and Use Artifacts in Spring Boot Project

Deploy jar or artifact to nexus server

Use and download jar/artifact from nexus server

Optional

Congratulations

Up and Running with gRPC

Let's Understand RPC!

When we choose gRPC?

gRPC vs REST

gRPC methods/operations

What is Protocol Buffer

gRPC vs Rest

Sample gRPC Based Micro-service Architecture

Congratulations

Securing cloud storage files with KMS

Create a Cloud Storage Bucket

Create a sample data

Enable Cloud KMS Service

Create KeyRing and CryptoKey

Encrypt our file

Decrypt our file

Cleanup environment

Congratulations

Journey to Google Cloud Platform (GCP)

🔰 Overview

🔰 About Google Cloud Platform

🔰 GCP offering me what? I have no idea about the Cloud!

🔰 How much it cost? I'm not going to invest money in that!

🔰 I would like to Explore the Google Cloud Platform!

References

Unix File Symbolic Permission

Vi (Vim) Text base editor regular commands

Let's Look at Networking Modes

The Complete Dev. Startup Organization Setup with GitHub

🔰 1. Open an Organization

🔰 2. Organization Settings

🔰 3. Projects Management

🔰 4. Teams Management

🔰 5. People Management - Do Administrative Stuff.

🔰 6. Packages Management

🔰 7. Create a New Repository

🔰 8. How to Publish Project Source Code

🔰 9. Learn More about Git & Commands

📗 First Time Git Configuration

📗 The seven rules of a great Git commit message

📗 Branching, Merging and Tagging

📗 Merge Conflict

📗 Undoing Changes

📗 The git revert Command

📗 Relative Commit References for Back and forth

📗 Remove Local and Remote Commit

📗 Git Tag Command

🔰 References:-

Upload & takes control over the Youtube Data API

🔰 Bit of information about API

🔰 Setting up your API-Key or Pre-configuration.

🔰 Setup Youtube Data API Congifuraiton

🔰 I have attached a demo sample source code below,

🔰 Finally, Run & Test Application

🔰 References:

OpenShift Origin 3.11 (OKD) Installation on a CentOS 7 Multi-Node Cluster

Overview

🔰1. Prerequisites

🔰2. To access remotely through username & password, needs to Installing and Enabling OpenSSH

🔰3. Common steps for on all the machines or nodes [Here, Master, Compute, Infra], Login into each single machine

🔰4. Finally, log in into Master Machine and follow the below instructions,

🔰 References:

Manage Your're Mail Using IMAP

📗 IMAP Overview

📗 When Choose POP:-

📗 When Choose IMAP:-

📗 Enable IMAP permission for your E-Mail

🔰 Now, Setup IMAP Client

📗 Take a look at implementation,

📗 Bonus Section

🔰 References