Certified Jenkins Engineer
Extending Jenkins and Administration
Demo Reload Configuration from Disk
Reloading configuration from disk allows Jenkins to pick up changes made directly to its filesystem without requiring a full restart. This is useful when you’ve edited config.xml, moved or renamed jobs via CLI, or updated your Jenkins home directory externally.
When to Use “Reload Configuration from Disk”
Use this feature to apply external changes immediately:
| Scenario | Description | Command / UI Path |
|---|---|---|
Update config.xml | Edit system settings or messages | vi $JENKINS_HOME/config.xml |
| Rename or move jobs | Relocate job folders in the filesystem | mv $JENKINS_HOME/jobs/old-job $JENKINS_HOME/jobs/new-job |
| Adjust security or plugin configs | Change security realm, authorization strategy, or plugin files | N/A |
Note
Reloading configuration does not apply plugin installations or upgrades. For plugin changes, use Manage Plugins and restart if required.
1. Update Configuration via the Jenkins UI
- Navigate to Dashboard → Manage Jenkins → Configure System.
- Find the System Message field.
- Enter a new message (e.g., “Welcome to KodeKloud”) and click Save.
- Verify the dashboard shows your updated system message.
2. Edit Configuration on the Filesystem
- SSH into your Jenkins server and switch to the Jenkins home directory:
cd $JENKINS_HOME - Open the main configuration file in your preferred editor:
vi config.xml - Locate the
<systemMessage>tag. Example before change:<systemMessage>Welcome to coded.ku</systemMessage> - Update it to your desired text:
<systemMessage>Welcome to Dasher Technologies</systemMessage> - Save and exit the editor.
- Confirm the change:
Output should be:grep -i systemMessage config.xml<systemMessage>Welcome to Dasher Technologies</systemMessage>
At this point, the Jenkins UI still displays the old message, since the configuration hasn’t been reloaded.
3. Reload Configuration from Disk
- In Jenkins, go to Dashboard → Manage Jenkins.
- Scroll to Tools and Actions and click Reload Configuration from Disk.
- Confirm the prompt to proceed. Jenkins will re-import all configuration files.
After a few seconds, your dashboard’s System Message updates to “Welcome to Dasher Technologies.”
Warning
Performing a reload can briefly impact running jobs. Avoid frequent reloads during peak build activity.
Benefits of Reloading from Disk
- Instant application of file-based edits
- No need for a full Jenkins restart
- Applies to jobs, system settings, security, and folder configurations
References
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