Merge lp:~cjwatson/isitdeployable/version-no-cache into lp:isitdeployable

[Colin Watson]

Send "Pragma: no-cache" when checking version header.

Some sites (e.g. qastaging.launchpad.net) are behind a cache that may require some help to notice when the version header changes. Make some effort to avoid this.

[Daniel Manrique (roadmr)]

+1!

review: Approve

[Otto Co-Pilot (otto-copilot)]

Running landing tests failed
https://jenkins.ols.canonical.com/online-services/job/isitdeployable-docker/75/

[Otto Co-Pilot (otto-copilot)]

Running landing tests failed
https://jenkins.ols.canonical.com/online-services/job/isitdeployable-docker/76/

[Daniel Manrique (roadmr)]

Necro-merging, I hope it doesn't break anything :)

[Otto Co-Pilot (otto-copilot)]

Running landing tests failed
https://jenkins.ols.canonical.com/online-services/job/isitdeployable-docker/77/

[Daniel Manrique (roadmr)]

The day of reckoning is here, ols-jenkaas. Test not. Merge or merge not. There is no test.

review: Approve

=== modified file 'revtracker/tasks.py'
--- revtracker/tasks.py	2020-04-21 21:46:42 +0000
+++ revtracker/tasks.py	2021-03-23 13:38:07 +0000
@@ -682,6 +682,7 @@
     try:
         headers = requests.utils.default_headers()
         headers['user-agent'] += " (isitdeployable)"
+        headers["pragma"] = "no-cache"
         response = requests.head(info_url, headers=headers, timeout=2)
         response.raise_for_status()
     except (MissingSchema,