Recover_Jenkins_Password.md

To recover Jenkins credentials, follow one of these methods based on your setup:

1. If You Have Access to Jenkins Home Directory (config.xml method)

1. Stop the Jenkins Service:

   • Run the following command to stop Jenkins:

     sudo systemctl stop jenkins

2. Edit the config.xml File:

   • Navigate to the Jenkins home directory (default is /var/lib/jenkins on Linux).
   • Open the config.xml file in a text editor:

     sudo nano /var/lib/jenkins/config.xml

3. Disable Security Temporarily:

   • Look for the <useSecurity> tag in the config.xml file and set it to false:

     <useSecurity>false</useSecurity>

   • Save and close the file.

4. Restart Jenkins:

   • Start Jenkins again:

     sudo systemctl start jenkins

5. Login Without Authentication:

   • Open Jenkins in your browser; it should not require login.
   • Navigate to Manage Jenkins > Configure Global Security and reset the admin password or add a new user.

6. Re-enable Security:

   • Once you reset credentials, change <useSecurity> back to true in config.xml and restart Jenkins to re-enable security.

2. Using Jenkins CLI to Reset Password

If you have access to the Jenkins command line interface (CLI) and a known admin account exists:

1. Open Jenkins CLI:
   • Run the following command to reset a specific user’s password:

     java -jar jenkins-cli.jar -s http://localhost:8080/ groovy = <<EOF
     import jenkins.model.*
     def instance = Jenkins.getInstance()
     def user = instance.getUser("admin")
     user.setPassword("new_password")
     user.save()
     EOF

Replace "admin" with the username and "new_password" with the desired new password.

3. Reset Admin Password via Jenkins Script Console (if still logged in)

1. Navigate to the Jenkins Script Console:

   • Go to http://<jenkins_url>/script (requires login).

2. Run Script to Reset Password:

   • Run the following script in the console:

     import hudson.security.HudsonPrivateSecurityRealm
     def user = Jenkins.instance.securityRealm.createAccount("admin", "new_password")
     user.save()

This script resets the admin password to "new_password".

4. Restore from Backup

If you have a backup of Jenkins:

1. Restore the backup files to the Jenkins home directory.
2. Restart Jenkins to recover the previous credentials.

After following these methods, be sure to secure Jenkins again by re-enabling security and resetting passwords as needed.