tkav/jenkins-distributed

Distributed Jenkins Environment using Terraform

Jenkins Distributed Build

Creates a Jenkins master and nodes.

Usage

Setup variables (existing SSH Key in AWS required)

export TF_VAR_project_name=jenkins
export TF_VAR_key_name=key-name

Change backend details in meta.tf.

Run Terraform

terraform init
terraform plan
terraform apply

Setting up Jenkins

SSH into master

ssh ubuntu@JENKINS_MASTER_ADDRESS

jenkins_master_address will be outputted by terraform.

Retrieve administrator password:

sudo cat /root/.jenkins/secrets/initialAdminPassword

If using user_data_for_docker.sh use:

cat /opt/jenkins_home/secrets/initialAdminPassword

Go to jenkins_master_address on port 80 and paste admin password.

Install suggested plugins.

Setup the first admin user, click Next and Save and Finish.

• Click Next and Start using Jenkins.
• Click Manage Jenkins
• Configure System
• Set # of executors to 0 for master and Save

Setup nodes

• Click Manage Jenkins
• Manage Nodes
• New Node
• Node name: node 0, tick Permanent Agent and click Create
• Set # of executors to 2
• Remote root directory to /home/jenkins/jenkins_slave
• Launch method: Launch agents via SSH
• Enter private ip of node-0 as Host
• Add Credentials SSH Username with private key
• Enter jenkins for the username
• Enter the private key directly pasting in the private SSH key used to provision the instances
• Select Non verifying Vericiation Strategy
• Click Save

Repeat for the other nodes except use Copy from Existing Node and enter the name of the first node.

• Click ok
• Change the private ip of the node and click save

Create a job

• Click create a job from the homepage
• Enter a name
• Select freestyle project and click OK
• Tick Build periodically
• Enter a cron statement for the Schedule */1 * * * *
• Click Add build step, Execute Shell
• Enter echo "hello world" for the command
• Click Save

The new job will run every 1 minute on one of the nodes.

Log Retention

• Open the job from the homepage
• The build history is shown on the left sidebar
• Click a build number and open Console Output.
• You can see the hello world build executed on the node.
• Go back to the Project and click Configure
• Tick Discard old builds and set the Max # of builds to keep to 5.
• Click Save

Only 5 of the last builds for this project will be kept.

Build labels

• Open node configurations and configure Node 1

• Enter the node-1 for Labels

• Set usage to Only build jobs with label expressions matching this node

• Click Save

• Configure the test job from the previous step

• Tick Restrict where this project can be run

• Enter node-1 for the Label Expression

• Click Save

The next build will run on node-1.

Extend execution time

• Reconfigue the test job
• Change the shell command to the following:

echo "hello world"
sleep 15
echo "goodbye"

• Click Save

The next build will pause and run for longer. You should see the job in the Build Executor Status sidebar on the homepage when it executes.