Jenkins - HTML Publisher Plugin - No CSS is displayed when report is viewed in Jenkins Server

Question

I have a strange problem with the Jenkins HTML Publisher plugin, wherein all the fancy CSS I have added to the report is stripped out when viewed in Jenkins. If I download the report to local, I am able to see the CSS formatting. Is there a setting in Jenkins which allows CSS to be viewed?

My HTML Publisher Settings in Jenkins:

My Report Page when displayed in Jenkins :

My Report Page when displayed in Local :

Answer 1

Figured out the issue. Sharing it here for other users.

CSS is stripped out because of the Content Security Policy in Jenkins. (https://wiki.jenkins-ci.org/display/JENKINS/Configuring+Content+Security+Policy)

The default rule is set to:

sandbox; default-src 'none'; img-src 'self'; style-src 'self';

This rule set results in the following:

• No JavaScript allowed at all
• No plugins (object/embed) allowed
• No inline CSS, or CSS from other sites allowed
• No images from other sites allowed
• No frames allowed
• No web fonts allowed
• No XHR/AJAX allowed, etc.

To relax this rule, go to

1. Manage Jenkins->
2. Manage Nodes->
3. Click settings(gear icon)->

4. click Script console on left and type in the following command:

   System.setProperty("hudson.model.DirectoryBrowserSupport.CSP", "")

and Press Run. If you see the output as 'Result:' below "Result" header then the protection disabled. Re-Run your build and you can see that the new HTML files archived will have the CSS enabled.