Need a way to run UI Only Preview in Gitlab

[t83714]

Problem description

Currently, UI Only Preview in Gitlab won't run probably as web-server pod needs get the content of index.html from content API (http://content-api/v0/includeHtml.text).

We will see the following error:

{ FetchError: request to http://content-api/v0/includeHtml.text failed, reason: getaddrinfo ENOTFOUND content-api content-api:80
    at ClientRequest.<anonymous> (/usr/src/app/node_modules/node-fetch/index.js:133:11)
    at emitOne (events.js:96:13)
    at ClientRequest.emit (events.js:188:7)
    at Socket.socketErrorListener (_http_client.js:314:9)
    at emitOne (events.js:96:13)
    at Socket.emit (events.js:188:7)
    at connectErrorNT (net.js:1034:8)
    at _combinedTickCallback (internal/process/next_tick.js:80:11)
    at process._tickCallback (internal/process/next_tick.js:104:9)
  name: 'FetchError',
  message: 'request to http://content-api/v0/includeHtml.text failed, reason: getaddrinfo ENOTFOUND content-api content-api:80',
  type: 'system',
  errno: 'ENOTFOUND',
  code: 'ENOTFOUND' }

It won't impact system functionality in any way but it's good to have to test UI only feature in Gitlab.

Problem reproduction steps

Deploy a test site in Gitlab using UI Only Preview in Gitlab option

Screenshot / Design / File reference

[t83714]

fixed by #1843

[AlexGilleran]

🎉