Knowledge base article cannot be displayed on the customer portal when JSM is integrated with Confluence 8.5.7+

Issue Summary

Knowledge base article cannot be displayed on the customer portal when JSM is integrated with Confluence 8.5.7+. When attempting to preview a Knowledge Base article you receive an error message in the iframe popup "<confluence site URL> refused to connect":

Environment:

• Any JSM Data Center version
• Confluence Data Center on 8.5.7 or any higher version

Note

This issue only happens when Confluence is on 8.5.7.

More information about the root cause in the KB article: https://confluence.atlassian.com/jirakb/kb-preview-is-failing-with-a-refused-to-frame-site-because-an-ancestor-violates-the-following-content-security-policy-directive-frame-ancestors-self-error-in-browser-s-console-1388151291.html

Steps to Reproduce

• Integrate JSM with Confluence to provide Customers with a knowledge base
• Go to the customer portal and search for any KB article
• Click on the article to open it in an iFrame on the customer portal

Expected Results

The article should be displayed:

Actual Results

The article is not displayed and we receive an error message in the iframe popup "<confluence site URL> refused to connect":

Workaround

1. Set the below JVM parameters (on all nodes if you are using multi-node DataCenter cluster) to add the below argument to your setting for allowing only the Jira host to view Confluence content in an iFrame (please change <JIRA hostname> with yours before applying configuration.); - See Configuring System Properties for more on setting System Properties.

   CATALINA_OPTS="-Dhttp.header.security.content.security.policy.value=\"frame-ancestors 'self' <JIRA hostname>\" ${CATALINA_OPTS}"
   

2. Perform a rolling restart of Confluence