In this hands-on lab we will be creating a build agent on a second server, and then creating a build that runs only on that server. This will demonstrate the use of labels for the build.
Learning Objectives
Successfully complete this lab by achieving the following learning objectives:
- Configure SSH on the Remote Agent
Log into the master via SSH. From the master node, use SSH to log into the worker node.
On the worker node, create the directory for the user’s home:
sudo mkdir /var/lib/jenkinsAdd the user, assigning the home directory:
sudo useradd -d /var/lib/jenkins jenkinsMake the user the owner of their home directory:
sudo chown -R jenkins:jenkins /var/lib/jenkinsCreate an
.sshdirectory for thejenkinsuser:sudo mkdir /var/lib/jenkins/.sshRun
ssh-keygen. Hit Enter to accept defaults until it completes.Copy the contents of
~/.ssh/id_rsa.pubto the file/var/lib/jenkins/.ssh/authorized_keyscat ~/.ssh/id_rsa.pub # Copy the output sudo vi /var/lib/jenkins/.ssh/authorized_keys # Paste the output of cat and saveCopy the contents of
id_rsa, as this is the private key that we will paste into Jenkins.Exit the worker node.
Create an
.sshdirectory on the master in thejenkinsdirectory:sudo mkdir /var/lib/jenkins/.sshCopy the
known_hostsentry over from the/home/cloud_user/.sshdirectory to thejenkinsuser’s.ssh:cp ~/.ssh/known_hosts /var/lib/jenkins/.ssh- Set up the Node on the Jenkins Master
Log into the Jenkins master web interface at port :8080 using these credentials: username: student password: OmgPassword!.
In the Jenkins master, go to Manage Jenkins and select Manage Nodes and Clouds.
On this page, add a node.
Name the node worker1.
On the Remote root directory line, type /var/lib/jenkins.
Set the number of executors to 2.
On the Host line enter the IP address of the worker
On the Credentials line click Add.
In the credentials configuration page, set the type to SSH Username with private key.
Enter the username jenkins.
Enter the contents of the
id_rsaas the key.Set the description to jssh.
Save.
Select the credential you just created as the SSH credential.
Save.
Go to the worker node logs and ensure that the worker node is set up correctly.
- Test a Remote Build
Configure the master to use labels, to ensure default builds run on the remote:
- On the master node, on the left go to Manage Jenkins.
- Select Configure System.
- On the Labels line, enter master.
- Set Usage to Only build jobs with label expressions matching this node.
- Save.
Create a Freestyle project.
Create a build step that runs a shell command.
Enter:
hostname > location.txtCreate a post build step that archives the
*.txtfiles.Run the build.
Check the log to ensure that the build ran on the remote agent.
Check the artifact to ensure that it contains the hostname of the remote worker.
