Forem: Carmen

Setting Up Minecraft Server in AWS

Carmen — Tue, 26 Aug 2025 22:06:50 +0000

Hosting your own Minecraft server is one of the best ways to enjoy the game with friends, explore custom worlds, or add plugins that make the experience unique. In this guide, we’ll walk through how to set up a fully functional Minecraft server on Amazon Web Services (AWS) using EC2. By the end, you’ll have a server that starts automatically, uses a static IP so players can always connect, and can be customized with plugins or new worlds, all while keeping costs under control.

Step 1: Set up the Server (EC2 Instance)

Log in to AWS Management Console.
Choose a region: In the top-right corner, select the AWS region closest to your players.

Example: If most players are on the US West Coast, select one of the us-west regions.
Open the EC2 service: Search for EC2 in the console search bar and open the dashboard.
Launch a new instance: Click on Launch instance.
Configure the instance:
1. Give the instance a descriptive name, such as “Minecraft Server”.
2. Choose Amazon Linux 2023 AMI.
3. Set the architecture to 64-bit (Arm).
Select the instance type:
1. Start with t4g.small, which is enough for a basic Minecraft server (it’s fine for a few players, but laggy with mods or >5 players. If you expect more, go to t4g.medium or larger).
2. If you need more performance later, you can resize/upgrade the instance.
3. For compute-intensive workloads, consider using the C family (Compute Optimized) instances.
Create a Key Pair:
1. Under Key pair name, click Create a new key pair.
2. Enter a name for the key (e.g., minecraft-key).
3. Click Create a key pair.
4. The private key file (.pem) will be automatically downloaded to your computer. Keep this file safe (you will need it later if you want to connect to the server).
Configure Network Settings:
1. Scroll down to the Network settings section and click Edit.
2. Select the default VPC. Leave the subnet as No preference.
3. Make sure Auto-assign public IP is enabled.
4. Under Firewall (security groups):
  1. Choose Create security group.
  2. Name it something like Minecraft Server SG.
  3. (Optional) Add a description such as: Security group for Minecraft Server. Ports open for SSH (22) and Minecraft TCP (25565).
5. Add inbound rules:
  1. SSH access (EC2 Instance Connect):
    1. By default, SSH (port 22) is enabled, but you must restrict it to the correct IP range for EC2 Instance Connect in you AWS region.
    2. Find the correct CIDR range in the AWS IP address ranges documentation.
    3. For example, in the eu-west-3 (Paris) region, the IP CIDR range is: 35.180.112.80/29 .
    4. In Inbound rules, edit the SSH rule and set Source Custom, then paste the correct IP range for your region.
      
      💡 Tip: To find the IP CIDR, download the JSON file from the documentation, open it in your browser as raw data, and search (Control+F) for EC2_INSTANCE_CONNECT.
  2. Minecraft traffic: Add another inbound rule:
    1. Type: Custom TCP.
    2. Port Range: 25565.
    3. Source: 0.0.0.0/0 (to allow players to connect).
Add Storage:
1. By default your instance comes with an 8 GB gp3 root volume, which is enough for a small server.
2. If you expect more data (e.g., larger worlds, mods, or backups), you may increase the size here.
3. AWS Free Tier includes up to 30GB of Elastic Block Storage (EBS), so you can expand the volume without leaving the free tier (as long as you stay under the 30GB).

Step 2: Set up Minecraft Automatically

Add a startup script: We’ll use a bash script so that the Minecraft server is automatically downloaded, configured and started every time the EC2 instance launches.

Locate the User Data field:

Scroll down to the Advanced Details section.
Expand it, then scroll to the bottom to find the User data field.

Copy and paste the following script into that field:

#!/bin/bash
set -euo pipefail

# ===== CONFIG =====
# Replace with the latest server .jar URL from the official page
MINECRAFT_URL="https://piston-data.mojang.com/v1/objects/6bce4ef400e4efaa63a13d5e6f6b500be969ef81/server.jar"
MINECRAFT_DIR="/opt/minecraft/server"
MINECRAFT_USER="minecraft"
SERVICE_NAME="minecraft"

# ===== PREREQS =====
# Install Java (Amazon Corretto)
sudo yum install -y java-21-amazon-corretto-headless

# Create a dedicated user and directories
id -u "$MC_USER" >/dev/null 2>&1 || useradd --system --create-home --shell /sbin/nologin "$MC_USER"
mkdir -p "$MC_DIR"
cd "$MC_DIR"

# ===== DOWNLOAD SERVER =====
# Download the Minecraft server JAR from the URL
# (Overwrites existing server.jar if present)
wget -O server.jar "$MINECRAFT_URL"

# ===== FIRST BOOT TO GENERATE FILES =====
# Run once to create eula.txt and default configs (ignore non-zero exit)
java -Xmx1024M -Xms1024M -jar server.jar nogui || true

# Accept EULA
sed -i 's/false/true/p' eula.txt

# ===== CALCULATE HEAP SIZE FROM TOTAL RAM =====
# Use ~50% of total memory, clamp to [1024, 16384] MB, round down to nearest 256 MB
TOTAL_MEM_MB=$(awk '/MemTotal/ {printf "%.0f", $2/1024}' /proc/meminfo)
XMX_MB=$(( TOTAL_MEM_MB / 2 ))
if [ "$XMX_MB" -lt 1024 ]; then XMX_MB=1024; fi
if [ "$XMX_MB" -gt 16384 ]; then XMX_MB=16384; fi
XMX_MB=$(( (XMX_MB/256)*256 ))

# ===== START/STOP SCRIPTS =====
# Create start script
cat > start <<'EOF'
#!/bin/bash
set -euo pipefail

MC_DIR="/opt/minecraft/server"
cd "$MC_DIR"

# Recompute heap on each start (handles instance type changes)
TOTAL_MEM_MB=$(awk '/MemTotal/ {printf "%.0f", $2/1024}' /proc/meminfo)
XMX_MB=$(( TOTAL_MEM_MB / 2 ))
if [ "$XMX_MB" -lt 1024 ]; then XMX_MB=1024; fi
if [ "$XMX_MB" -gt 16384 ]; then XMX_MB=16384; fi
XMX_MB=$(( (XMX_MB/256)*256 ))

ulimit -n 4096
exec java -Xmx${XMX_MB}M -Xms${XMX_MB}M -jar server.jar nogui
EOF
chmod +x start

# Create stop script
cat > stop <<'EOF'
#!/bin/bash
# Graceful stop via systemd is preferred: systemctl stop minecraft
# Fallback: kill Java owned by the minecraft user running the server.jar
pkill -u minecraft -f 'java .*server\.jar' || true
EOF
chmod +x stop

# Permissions
chown -R "$MC_USER":"$MC_USER" /opt/minecraft

# ===== SYSTEMD SERVICE =====
# Create a systemd service to run Minecraft on startup
cat << 'EOF' > /etc/systemd/system/minecraft.service
[Unit]
Description=Minecraft Server
Wants=network-online.target
After=network-online.target

[Service]
User=${MC_USER}
WorkingDirectory=${MC_DIR}
ExecStart=${MC_DIR}/start
ExecStop=${MC_DIR}/stop
Restart=on-failure
RestartSec=15
NoNewPrivileges=true
ProtectSystem=full
ProtectHome=true
PrivateTmp=true

[Install]
WantedBy=multi-user.target
EOF

# Enable and start the service
systemctl daemon-reload
systemctl enable ${SERVICE_NAME}.service
systemctl start ${SERVICE_NAME}.service

Get the latest Minecraft server link:
1. To ensure you’re running the newest version, go to the official Minecraft Server download page.
2. Find the link to “Download minecraft_server.jar”.
3. Right-click the minecraft_server.jar link and copy the URL.
4. Replace the value of MINECRAFT_URL in the script above with this new link.
Launch the instance:
1. Once you’ve added the script, click Launch Instance.
2. The EC2 instance may take 5-10 minutes on first boot while it installs dependencies and sets up the server.
  
  🧪 Test: After the instance finishes launching, copy its public IPv4 address from the EC2 console. Open Minecraft, go to Multiplayer, add a new server, and paste the IP address. Within a few minutes, you should be able to connect to your new Minecraft server.

Step 3: Set Up Static IP

Every time an EC2 instance turns off, its public IP address will change. Having to search for your new IP every time you turn your server on and off is inefficient. We will associate an Elastic IP with our EC2 instance to solve this problem. Elastic IP addresses are dedicated IP addresses that do not change and can be attached to different resources.

Open Elastic IPs:
1. In the EC2 dashboard, expand the left-hand menu.
2. Under Network & Security, click Elastic IPs.
Allocate an Elastic IP:
1. Click Allocate Elastic IP address (top right).
2. Choose Public IPv4 from Amazon’s pool of IPv4 addresses.
3. Click Allocate.
Name the IP: To keep things organized, rename the Elastic IP to something descriptive, like Minecraft Server IP.
Associate the Elastic IP with the instance:
1. Select the new Elastic IP.
2. Click Actions → Associate Elastic IP Address.
3. For Resource type, choose Instance.
4. From the drop-down list, select the Minecraft EC2 instance we created before.
5. Click Associate.
Verify the Elastic IP:
1. Go back to the Minecraft EC2 instance details.
2. Under Public IPv4 address, we should now see the Elastic IP.
Connect to the server in Minecraft:
1. Open Minecraft and go to the Multiplayer screen.
2. Click Add Server (or use Direct Connect).
3. In the Server Address field, enter the Elastic IP.
4. The server should now be accessible with the static IP every time you restart the instance.

⚠️ Warning: Elastic IPs are free **as long as they are attached to a running instance. If you allocate one but don’t associate it with anything, AWS may charge you a small hourly fee.

Extra: Customize the Server (Plugins, World Files, etc.)

Once the server is up and running, you may want to install plugins, change the world, or modify configuration files. To do that, you’ll need to connect directly to your EC2 instance.

Connect to the instance:
1. Go to the EC2 dashboard and select the Minecraft server instance.
2. Click Connect at the top.
3. In the connection screen, make sure the user is set to ec2-user, then click Connect again.
4. If the connection fails, try rebooting the instance and waiting a few minutes, or review the common troubleshooting tips.
Navigate to the server directory:
1. After logging in, you’ll be in a terminal.
2. Run: cd /opt/minecraft/server/. This directory contains all the Minecraft server files. Remember this location for future edits.
3. To check the server files, use the following command: ls . You should see files like world/, logs/, server.jar, as well as the start and stop scripts.
Stop the server before making changes:
1. The server console runs in the background, so files can’t be edited while it’s active.
2. To stop the server, run: sudo systemctl stop minecraft .
3. Once the service is stopped, you can upload a new world, add plugins or edit configuration files.
Restart the server:
1. After making changes, restart the instance or run: sudo systemctl start minecraft .

💡 Useful commands:

# Start the server
sudo systemctl start minecraft

# Stop the server
sudo systemctl stop minecraft

# Restart the server
sudo systemctl restart minecraft

# Check if the server is running
sudo systemctl status minecraft

Clean Up (Avoid Extra Charges)

When you’re done testing or hosting your server, it’s important to shut down resources to prevent ongoing AWS charges.

Terminate the EC2 instance:
1. In the EC2 dashboard, select your Minecraft instance.
2. Click Instance state → Terminate instance.
3. Confirm the termination.
Release the Elastic IP:
1. In the EC2 dashboard, open the sidebar and go to Elastic IPs.
2. Select the Elastic IP you associated with your instance.
3. Click Actions → Release Elastic IP addresses.

Once done, you will no longer incur charges from this setup.

Resources & Useful Links

Text-To-Speech in Python

Carmen — Mon, 26 Feb 2024 09:13:36 +0000

Introduction

I’ve been working in the development of Python software that aimed to enable playing chess directly from the terminal. Initially, the project was conceive as a platform for local matches between players or against a bot, as well as online games.

In addition to its primary functionality, the project’s focus has shifted towards becoming an accessible tool for people with functional diversity, implying the integration of assistive technologies such as Text-To-Speech to ensure an inclusive experience.

In this regard, I have dedicated time to researching the available options in Python for implementing text-to-speech for free.

Library Installation

Firstly, it’s crucial to consider the libraries that will allow us to incorporate Text-To-Speech into our software. Among these libraries, we will be using:

Google Text-to-Speech (gTTS): Used for generating audio files from the provided text.
Pygame: Used for playing the generated audio without concerns regarding device compatibility or operating systems.

Code

from gtts import gTTS
import pygame

# Initialize Pygame mixer
pygame.mixer.init()

# Path to the audio file
sound_file = "sound_file.mp3"

# Generate audio from text
text_to_speech = gTTS(text='Hi, good evening', lang='en')
tts.save(sound_file)

# Load the audio file into Pygame
sound = pygame.mixer.Sound(sound_file)

# Play the audio
sound.play()

# Wait for the sound to finish playing
while pygame.mixer.get_busy(): 
    pygame.time.delay(100)

This simple code demonstrates how to use the gTTS library to convert specific text, in this case, “Hi, good evening”, into an audio file in MP3 format. Subsequently, using Pygame, we play the audio file.

How I sync my Obsidian vault across devices

Carmen — Mon, 11 Apr 2022 23:24:56 +0000

In the last few days, I’ve trying to improve my productivity and with it my note-taking system. Over the last couple of years, I've tried different tools, from Notion, Evernote, Google Docs, Google Keep, etc. In the end and after many hesitations, research and testing, I have concluded that the best software for me is Obsidian.md. Obsidian is a handy little program that uses links to connect notes. It is based on Markdown, which is a lightweight language used for writing and formatting plain text documents.

One advantage that Obsidian offers over many other applications is that it is completely free but within certain nuances. That is, for personal use it is 100% free, you don't need to register, and it offers access to many plugins and community support. Thanks to this, the fact that the possibility of syncing your notes through Obsidian is a paid feature was not a drawback. This is because I have decided to use git, software for tracking changes in any set files, and GitHub as the cloud-based git repository hosting service.

In this way, I only had to install and set up git on my different devices and clone the repository. In case anyone is wondering, my devices are a desktop pc, an iPad, and a phone (Android). I built my system as follows:

First of all, I created the repo on GitHub. Afterward, on my pc I installed Obsidian and with Gitkraken, a graphical interface for git, I cloned the repo to my local machine. For anyone who wants to build a similar system, there is no need to use Gitkraken, you may directly use git from the command line as well as other graphical interfaces such as GitHub Desktop or Sourcetree. Then, the only thing left to do was to use my repository as the base folder for the Obsidian vault.

On the other hand, as for the iPad, the tools I use are Working Copy and the Obsidian app. I must admit that the setup on my iPad took me a bit longer since I didn't know how to do it at first, but I don't have any regrets since I have found the way that best suits my needs. You may pull repos with the free version of Working Copy, but I think you need the pro version to push to a repo (You may access all Pro features while you are a student through the GitHub Student Developer Pack). To start with the setup, you need to download the Obsidian app from the App Store and create a new vault. On the creation screen, you need to make sure that Store in iCloud isn’t selected.

Next, after downloading Working Copy will have to configure the credentials for the git host (GitHub, Bitbucket, GitLab…) where you have the repo. Once you are done, clone the repo. Subsequently, from Working Copy, open the repo, select the “share menu” and click on the Setup Folder Sync option. Under the On My iPad section there should be an Obsidian folder that contains the Obsidian vault folder which you need to select. This step is crucial because it’s the way to sync the repo with the vault.

Finally, the configuration that I honestly find the most time-consuming and complicated. The first thing to do is to install Termux, an android terminal application, and a Linux environment. There are two ways to download the latest version of Termux: F-droid and GitHub. Once we have successfully installed Termux we must run a series of commands:

apt update && upgrade. With this command, we will update all the packages in Termux.
termux-setup-storage . Allow Termux to access your existing directories.
pkg install git . Install git.
pkg install gh . Not needed, but recommended. It’s a command-line tool by GitHub.
gh auth login . Login into your GitHub account.
git config --global user.name “your name” . Global git username associated with commits on all repositories in your system.
git config --global user.email “youremail@yourdomain.com” . Global git email address associated with commits on all repositories in your system.
git clone “your repo link” . Clone the repo to your local environment.
mv “your repo name”/ storage/shared/ . Move the repo to the shared folder so you may access it from any Android app.

When using obsidian on your different devices, always remember to pull down the latest repo changes and commit and push any changes you make afterward!!

Thanks for reading this far!! I will be leaving links to resources below, in case it helps!! I’m open to constructive criticism, feedback and suggestions 😊

Resources & Useful links: