How to Setup Self-Hosted Linux Docker Build Agent in Azure DevOps | How to configure Self-Hosted Linux Docker Agents in Azure Pipelines | Create Custom Build Agents in Azure DevOps

 Setting up a self-hosted Linux Docker build agent in Azure DevOps involves several steps. You’ll be configuring a Linux machine to run Docker containers that act as build agents for Azure Pipelines. Here’s a comprehensive guide to help you through the process:

1. Prepare Your Linux Machine

1. Install Docker:

   • Update the package index:

     
     sudo apt-get update
     

   • Install Docker:

     
     sudo apt-get install -y docker.io
     

   • Start and enable Docker service:

     
     sudo systemctl start docker
     sudo systemctl enable docker
     

   • Verify Docker installation:

     
     docker --version
     

2. Install Docker Compose (Optional):

   • Download Docker Compose:

     
     sudo curl -L "https://github.com/docker/compose/releases/download/$(curl -s https://api.github.com/repos/docker/compose/releases/latest | grep tag_name | cut -d '"' -f 4)/docker-compose-$(uname -s)-$(uname -m)" -o /usr/local/bin/docker-compose
     

   • Apply for executable permissions:

     
     sudo chmod +x /usr/local/bin/docker-compose
     

   • Verify Docker Compose installation:

     
     docker-compose --version
     

2. Set Up Azure DevOps Self-Hosted Agent

1. Create a Personal Access Token (PAT):

   • Go to your Azure DevOps organization in your browser.
   • Navigate to User Settings > Personal Access Tokens.
   • Click on New Token and create a token with the appropriate scopes, typically including "Agent Pools (read, manage)".

2. Download and Configure the Agent:

   • Go to Project Settings in your Azure DevOps project.
   • Navigate to Agent Pools and create a new pool if needed.
   • Click on the pool, then click New Agent.
   • Select Linux as the agent type.
   • Download the agent package:

     
     mkdir myagent && cd myagent
     curl -O https://vstsagentpackage.azureedge.net/agent/2.206.0/vsts-agent-linux-x64-2.206.0.tar.gz
     

   • 

   • Extract the agent package:

     tar zxvf vsts-agent-linux-x64-2.206.0.tar.gz
     

   • 

   • Configure the agent:

     ./config.sh
     

     • Provide your Azure DevOps URL and PAT when prompted.
     • Choose the agent pool you created.
     • Set the agent name.
     • Confirm the agent configuration.

3. Run the Agent:

   • Start the agent:

     ./run.sh

   • Optionally, configure the agent as a service to start automatically:

     sudo ./svc.sh install
     sudo ./svc.sh start
     

3. Set Up Docker-Based Builds

1. Create a Dockerfile for the Build Agent:

   • Example Dockerfile:

     
     FROM mcr.microsoft.com/dotnet/sdk:7.0 AS build
     
     # Install necessary tools (example: git, curl, etc.)
     RUN apt-get update && \
         apt-get install -y git curl
     
     # Create a non-root user
     RUN useradd -m builduser
     USER builduser
     
     # Set up the working directory
     WORKDIR /build
     
     # Set up any necessary environment variables
     ENV PATH="/build:${PATH}"
     

2. Build and Push the Docker Image:

   • Build the Docker image:

     
     docker build -t my-build-agent:latest .
     

   • Push the image to a Docker registry (e.g., Docker Hub or Azure Container Registry):

     
     docker tag my-build-agent:latest <your-registry>/my-build-agent:latest
     docker push <your-registry>/my-build-agent:latest
     

3. Configure the Build Pipeline:

   • In Azure DevOps, create or edit a pipeline.
   • Use the Docker image in the pipeline configuration:

     
     pool:
       vmImage: 'ubuntu-latest'
     
     containers:
       - container: mybuild
         image: <your-registry>/my-build-agent:latest
     
     steps:
       - script: echo "Running in container"
         displayName: 'Run a one-line script'
     

4. Test Your Setup

• Create a sample pipeline to test if your self-hosted agent is correctly picking up and running jobs.
• Verify that builds are successfully executed and that your Docker-based agent is functioning as expected.

By following these steps, you'll have a self-hosted Linux Docker build agent running in Azure DevOps, which can help you manage and scale your build infrastructure effectively.