[jenkins] How to move Jenkins from one PC to another

I am currently using Jenkins on my development PC. I installed it on my development PC, because I had limited knowledge on this tool; so I tested on it in my development PC. Now, I feel comfortable with Jenkins as my long term "partner" in the build process and would like to "move" this Jenkins to a dedicated server.

Before this I have done few builds and have the artifacts archived from each build. In particular, the build number is very important to me for version control.

How can I export all the Jenkins information from my current PC to my new server?

Jenkins Server Automation:

Step 1:

Set up a repository to store the Jenkins home (jobs, configurations, plugins, etc.) in a GitLab local or on GitHub private repository and keep it updated regularly by pushing any new changes to Jenkins jobs, plugins, etc.

Step 2:

Configure a Puppet host-group/role for Jenkins that can be used to spin up new Jenkins servers. Do all the basic configuration in a Puppet recipe and make sure it installs the latest version of Jenkins and sets up a separate directory/mount for JENKINS_HOME.

Step 3:

Spin up a new machine using the Jenkins-puppet configuration above. When everything is installed, grab/clone the Jenkins configuration from the Git repository to the Jenkins home direcotry and restart Jenkins.

Step 4:

Go to the Jenkins URL, Manage Jenkins ? Manage Plugins and update all the plugins that require an update.

Done

You can use Docker Swarm or Kubernetes to auto-scale the slave nodes.

Let us say we are migrating Jenkins LTS from PC1 to PC2 (irrispective of LTS version is same of upgraded). It is easy to use ThinBackUp Plugin for migration or Upgrade of Jenkins version.

Step1: Prepare PC1 for migration

• Manage Jenkins -> ThinbackUp -> Setting
• Select correct options and directory for backup
• If you need a job history and artifacts need to be added then please select 'Back build results' option as well.

• Go back click on Backup Now.

Note: This Thinbackup will also take Plugin Backup which is optional.

• Check the ThinbackUp folder must have a folder with current date and timestamp. (wait for couple of minutes it might take some time.)
• You are ready with your back, .zip it and copy to PARTICULAR (which will be 'Backup directory') directory in PC2.
• Unzip ThinbackUp zipped folder.
• Stop Jenkins Service in PC1.

Step2: Install Jenkins (Install using .war file or Paste archived version) in PC2.

• Create Jenkins Service using command sc create <Jenkins_PC2Servicename> binPath="<Path_to_Jenkinsexe>/jenkins.exe"
• Modify JENKINS_HOME/jenkins.xml if needed in PC2.
• Run windows service <Jenkins_PC2Servicename> in PC2
• Manage Jenkins -> ThinbackUp -> Setting
• Make sure that you PERTICULAR path from step1 as Backup Directory in ThinBackup settings.
• ThinbackUp -> Restore will give you a Dropdown list, choose a right backup (identify with date and timestamp).

• Wait for some minutes and you have latest backup configurations including jobs history and plugins in PC2.
• In case if there are additional changes needed in JENKINS_HOME/Jenkins.xml (coming from PC1 ThinbackUp which is not needed) then this modification need to do manually.

NOTE: If you are using Database setting of SCM in your Jenkins jobs then you need to take extra care as all SCM plugins do not support to carry Database settings with the help of ThinbackUp plugin. e.g. If you are using PTC Integrity SCM Plugin, and some Jenkins jobs are using DB using Integrity, then it will create a directory JENKINS_Home/IntegritySCM, ThinbackUp will not include this DB while taking backup.

Solution: Directly Copy this JENKINS_Home/IntegritySCM folder from PC1 to PC2.

Sometimes we may not have access to a Jenkins machine to copy a folder directly into another Jenkins instance. So I wrote a menu driven utility which uses Jenkins REST API calls to install plugins and jobs from one Jenkins instance to another.

For plugin migration:

1. GET request: {SOURCE_JENKINS_SERVER}/pluginManager/api/json?depth=1 will get you the list of plugins installed with their version.

2. You can send a POST request with the following parameters to install these plugins.

   final_url=`{DESTINATION_JENKINS_SERVER}/pluginManager/installNecessaryPlugins`
   
   data=`<jenkins><install plugin="{PLUGIN_NAME}@latest"/></jenkins>` (where, latest will fetch the latest version of the plugin_name)
   
   auth=`(destination_jenkins_username, destination_jenkins_password)`
   
   header=`{crumb_field:crumb_value,"Content-Type":"application/xml”}` (where crumb_field=Jenkins-Crumb and get crumb value using API call {DESTINATION_JENKINS_SERVER}/crumbIssuer/api/json
   

For job migration:

1. You can get the list of jobs installed on {SOURCE_JENKINS_URL} using a REST call, {SOURCE_JENKINS_URL}/view/All/api/json
2. Then you can get each job config.xml file from the jobs on {SOURCE_JENKINS_URL} using the job URL {SOURCE_JENKINS_URL}/job/{JOB_NAME}.
3. Use this config.xml file to POST the content of the XML file on {DESTINATION_JENKINS_URL} and that will create a job on {DESTINATION_JENKINS_URL}.

I have created a menu-driven utility in Python which asks the user to start plugin or Jenkins migration and uses Jenkins REST API calls to do it.

You can refer the JenkinsMigration.docx from this URL jenkinsjenkinsmigrationjenkinsrestapi

This worked for me to move from Ubuntu 12.04 (Jenkins ver. 1.628) to Ubuntu 16.04 (Jenkins ver. 1.651.2). I first installed Jenkins from the repositories.

1. Stop both Jenkins servers

2. Copy JENKINS_HOME (e.g. /var/lib/jenkins) from the old server to the new one. From a console in the new server:

   rsync -av username@old-server-IP:/var/lib/jenkins/ /var/lib/jenkins/

3. Start your new Jenkins server

You might not need this, but I had to

• Manage Jenkins and Reload Configuration from Disk.
• Disconnect and connect all the slaves again.
• Check that in the Configure System > Jenkins Location, the Jenkins URL is correctly assigned to the new Jenkins server.

In case your JENKINS_HOME directory is too large to copy, and all you need is to set up same jobs, Jenkins Plugins and Jenkins configurations (and don't need old Job artifacts and reports), then you can use the ThinBackup Plugin:

1. Install ThinBackup on both the source and the target Jenkins servers

2. Configure the backup directory on both (in Manage Jenkins ? ThinBackup ? Settings)

3. On the source Jenkins, go to ThinBackup ? Backup Now

4. Copy from Jenkins source backup directory to the Jenkins target backup directory

5. On the target Jenkins, go to ThinBackup ? Restore, and then restart the Jenkins service.

6. If some plugins or jobs are missing, copy the backup content directly to the target JENKINS_HOME.

7. If you had user authentication on the source Jenkins, and now locked out on the target Jenkins, then edit Jenkins config.xml, set <useSecurity> to false, and restart Jenkins.