1560031 - Only push /etc/hosts file once during wptrunner setup

Status: RESOLVED DUPLICATE of bug 1560033

(Testing :: web-platform-tests, enhancement)

Description

[Henrik Skupin [:whimboo][⌚️UTC+2]]

Currently we push the /etc/hosts file each time the browser application gets started, even nothing changes in it.

After talking to James and Maja we should best move it to the setup/initialization of wptrunner.

Comment 1

[Maja Frydrychowicz :impossibus (was :maja_zf) (needinfo me)]

Some archaeology:

• This was added back in Bug 1323620.
• We write the hosts file in FennecBrowser.start: https://searchfox.org/mozilla-central/rev/b3b401254229f0a26f7ee625ef5f09c6c31e3949/testing/web-platform/tests/tools/wptrunner/wptrunner/browsers/fennec.py#201
• I recall trying to get wpt test urls working with network.proxy.autoconfig* prefs but I couldn't get it to work on mobile back then, hence the hosts file solution.

Comment 2

[Maja Frydrychowicz :impossibus (was :maja_zf) (needinfo me)]

(Oh and forgive the "Fennec" naming everywhere. This code is also for GeckoView now.)

Comment 3

[Henrik Skupin [:whimboo][⌚️UTC+2]]

Something I missed and what James mentioned on IRC is that we actually have a check if the newly generated hosts file is different from the current one, and only push it under such a condition:

https://searchfox.org/mozilla-central/rev/b3b401254229f0a26f7ee625ef5f09c6c31e3949/testing/web-platform/tests/tools/wptrunner/wptrunner/browsers/fennec.py#90

It means that we only do it once if all is fine with the emulator, but could fail again and again if there are remount problems of the system partition and the newly hosts file cannot be pushed.