Some javadoc resources unavailable

Hi @ctrueden,

I just figured out that the ImageJ related javadoc pages on the page seem to be unavailable by today (at least for me). Not sure if someone else can reproduce that and if this is just due to any server maintenance going on or if this is really an undesired problem?

Edit: seems to be just a link issue …does not work …works

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It is a security issue with recent versions of Jenkins. We upgraded the ImageJ Jenkins yesterday, which caused us to become affected by the issue.

I have now instituted a configuration change on the server side to avoid the issue.

You may need to force refresh (e.g., Shift+F5 or Shift+Ctrl+R) to see the javadoc again.

Technical details

From the Jenkins Configuring Content Security Policy page:

Jenkins 1.641 / Jenkins 1.625.3 introduce the Content-Security-Policy header to static files served by Jenkins (specifically, DirectoryBrowserSupport). This header is set to a very restrictive default set of permissions to protect Jenkins users from malicious HTML/JS files in workspaces, /userContent, or archived artifacts.

Unfortunately, several popular, useful plugins are affected by this and lose part of their functionality unless the default rules are relaxed.

The Javadoc Plugin makes Javadoc available for browsing in Jenkins. The default rule set does not allow use of frames in pages served by Jenkins. To make this work again, the directives frame-src 'self' and child-src 'self' must be added to the CSP header. It appears Safari also requires the sandbox directive to be removed.

default-src 'none'; img-src 'self'; style-src 'self'; child-src 'self'; frame-src 'self';

The ImageJ Jenkins now applies this fix via /etc/default/jenkins which includes the line:

JAVA_ARGS="$JAVA_ARGS -Dhudson.model.DirectoryBrowserSupport.CSP=\"default-src 'none'; img-src 'self'; style-src 'self'; child-src 'self'; frame-src 'self';\""

Without this change, Javadoc pages served by Jenkins are blank, e.g. with Chrome reporting:

Blocked script execution in ‘’ because the document’s frame is sandboxed and the ‘allow-scripts’ permission is not set.


Note that other recently upgraded Jenkins systems, such as the OME Jenkins, also suffer from this problem (at the time of this writing).


Thanks @ctrueden for fixing this.

There remains an issue with at the time of this writing, and trying to access the KNIME API via gives 503 Service Temporarily Unavailable.

Thanks @ctrueden for the explanation and clarification

And btw happy new year to all of you. :smile:

The OME team has been notified and will have to apply a similar fix to their Jenkins server.

Looks to be up now.

Oh, it’s their Jenkins that takes care of it. I got confused by the domain.

Yes, perfect! Thanks :smile:

Reverse proxy magic :wink:

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Note that as noticed by @imagejan, we also had to add script-src 'unsafe-inline' to the rule set, or else javadoc URLs including a query (e.g.: did not work properly.

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