Issue Summary

When Jira is connected to 2 Confluence server instances via an application link, the Knowledge Base search functionality might not work from the main Help Center page, while it will still work from the individual portal search page and the request creation page.

Currently, Help Center search performs the search exclusively on the Primary Confluence instance and no other. 

This is a request to able to resolve this - through either -

1. Provide the ability to select which confluence instance is used in the Help Center searches
2. Or enable ability to search on all connected Connies

Steps to reproduce

• Setup 2 Confluence instances
  • The first one will be referred to as Confluence
  • The second one will be referred to as Confluence 2
• Create a new space in Confluence, and create a few pages containing the word "laptop"
• Setup 1 Jira instance
• Configure 2 application links in Jira > ⚙ > Applications > Application Links, 1 to each Confluence instance, with the application link to Confluence set to the primary one:
  
• Create a Service Desk project in Jira, and configure there a knowledge base using the space coming from Confluence
  
• Go to the main help center page of the customer portal (<JIRA_BASE_URL>/servicedesk/customer/portals)
• Type "laptop" in the search, and notice that the search is returning articles coming from Confluence (in addition to the relevant Request Types from JSD projects)
  
• Go back to Jira > ⚙ > Applications > Application Links and now set Confluence 2 as the primary link
  
• Go back to the main help center page of the customer portal (<JIRA_BASE_URL>/servicedesk/customer/portals)
• Type "laptop" in the search

Actual Results

• The search does not return any article from Confluence, but only the relevant Request Types from JSD projects:
  
• When opening the Browser Dev tool, we can see that no pages are returned from the request <JIRA_BASE_URL>/rest/servicedesk/knowledgebase/latest/articles/shared/search?resultsPerPage=3&pageNumber=1&query=laptop&_=1627633567284

  {"results":[],"total":0,"pageNumber":0,"resultsPerPage":0,"isCloud":false}
  

  

• When enabling the debugging package org.apache.http in Logging And profiling, we don't see any outbound HTTP request sent from Jira to Confluence, which shows that the Jira application did not try to send any request to Confluence to search for these articles

Expected results

• The search should be returning articles coming from Confluence (in addition to the relevant Request Types from JSD projects)
• When enabling the debugging package org.apache.http in Logging And profiling, we should see Jira sending outgoing HTTP requests to Confluence to search for the key word "laptop" within the Confluence space linked to the JSD project. For example:

  2021-07-30 07:54:36,610+0200 http-nio-8093-exec-10 url: /jira8130/rest/servicedesk/knowledgebase/latest/articles/shared/search; user: julien DEBUG julien 474x2108x1 znpp6o 0:0:0:0:0:0:0:1 /rest/servicedesk/knowledgebase/latest/articles/shared/search [o.apache.http.wire] http-outgoing-1392 >> "GET /confluence712/rest/knowledge-base/1.0/search?type=page&queryString=%28laptop%29+AND+%28spacekey%3ANEWIT+OR+spacekey%3AAB+OR+spacekey%3AGERMANIT+OR+spacekey%3AKBFOR%29&pageSize=3&startIndex=0&highlight=true&xoauth_requestor_id=julien HTTP/1.1[\r][\n]"
  

Workaround

Set the Confluence application which is used as the Knowledge Base as the primary application link in Jira > ⚙ > Applications > Application Links.