1913346 - Treeherder fails to load Treestatus information via API on initial load, blocked by CSP

Status: NEW

(Conduit :: Lando, defect)

Description

[Sebastian Hengst [:aryx] (needinfo me if it's about an intermittent or backout)]

This might have been mentioned in a different bug before.

1. Load https://treeherder.mozilla.org/ in a new tab.
   Actual result: Tree(s) in the second toolbar (e.g. 'try', 'autoland', 'mozilla-central') have a question mark as icon.
   Expected result: The trees have icons as information about the tree's status, e.g. green circle, orange lock, red cross mark.

2. Reload the tab.
   Actual & expected result: The trees have treestatus information.

From the developer's network console (with Firefox 131.0a1):

Initial request:

GET /trees/autoland undefined
Host: treestatus.prod.lando.prod.cloudops.mozgcp.net
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:131.0) Gecko/20100101 Firefox/131.0
Accept: */*
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate, br, zstd
Referer: https://treeherder.mozilla.org/
Origin: https://treeherder.mozilla.org

Second request (reload):

GET /trees/autoland HTTP/2
Host: treestatus.prod.lando.prod.cloudops.mozgcp.net
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:131.0) Gecko/20100101 Firefox/131.0
Accept: */*
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate, br, zstd
Referer: https://treeherder.mozilla.org/
Origin: https://treeherder.mozilla.org
DNT: 1
Connection: keep-alive
Sec-Fetch-Dest: empty
Sec-Fetch-Mode: cors
Sec-Fetch-Site: cross-site
Priority: u=4
Pragma: no-cache
Cache-Control: no-cache