DevOps Classroom Series – 03/Dec/2021

Configuring Distributed Builds with Jenkins

• Initial Lab setup
  • Jenkins master
    • Configuration: 2 VCPUs 4 GB of RAM
    • Operating System: ubuntu 20.04
    • Softwares: JDK 11, Jenkins LTS, git
  • Jenkins node 1:
    • Configuration: 2 VCPU 4 GB of RAM
    • Operating System: ubuntu 20.04
    • Softwares: Jdk 11, maven latest, git
• Note: There should be connectivity between master and node
• Lab Setup Overview
• I will be creating both the machine in AWS
• Now lets install jenkins on jenkins master
• Once the jenkins server is up, set the necessary permissions for the jenkins user to perform actions on jenkins master
• Now we have jenkins master setup. Now we need to configure the jenkins node
• The way jenkins master will communicate with Jenkins node if it is linux
  • The jenkins master will login into jenkins node using ssh => username & password or username & key
  • So on the nodes for this sessions, lets create a user called as devops on all the nodes.
  • We would create a user devops and we would be giving them sudo permissions as well
  • Now lets create a devops user with some password
    • In linux machines (AWS or in other clouds) login with password might be disabled so we need to enable it first => change PasswordAuthentication to yes in /etc/ssh/sshd_config file and restart sshd service
    • Create user
      • debian => sudo adduser devops
      • redhat => sudo adduser devops & sudo passwd devops
    • Grant sudo permissions with no password to devops as this will be used by jenkins
    • Refer Here to the previous class room notes to install jdk 11 and maven latest
  • When we create jenkins job, how can we tell jenkins to run a partiular job on a particular node
• Jenkins node configuration
  • Screen Shots
  • Once you save the node we can verify if the node is connected or not
• Now lets create a jenkins job which will build the spring pet clinic project
• Now let build to verify if the job is getting scheduled on the remote node or not
• Next Steps: Lets try to fix the problem of maven not found (mvn not found)