The image builder image we use to build docker images is updated manually, and not necessarily when changes occur in tree that should be reflected by a new image builder image. For instance, its run-task is currently outdated. Not enough that it's actually a problem, but it could rapidly become a problem. There is also a lot of friction when trying to make changes in how docker images are built, and while last time I tried, I ended up not being able to do the changes I wanted to make because the docker version on the host is too old, but this is already the second time I've been trying to make things better and hit a wall because the the image builder is essentially fixed in stone on the docker hub. So with this change, we make all the docker images use the in-tree image builder image, except itself, obviously. That one uses the last version that was uploaded. We may want to update it at some point, but not doing so will only impact building the image builder image itself, not the other ones. Review commit: https://reviewboard.mozilla.org/r/212386/diff/#index_header See other reviews: https://reviewboard.mozilla.org/r/212386/

In many cases, building docker images starts on machines that don't have a cached checkout, and it often takes forever to get a full clone. It used to be worsened when 3 jobs could run at the same time because the worker would start up clean, and 3 jobs would be doing a mercurial clone at the same time, thrashing I/O, but that part is fortunately fixed. It is still, however, appreciable not to waste time in the mercurial clone part of image creation. Review commit: https://reviewboard.mozilla.org/r/212388/diff/#index_header See other reviews: https://reviewboard.mozilla.org/r/212388/

Comment on attachment 8942123 [details] Bug 1430037 - Use the in-tree image builder image to build docker images. Review request updated; see interdiff: https://reviewboard.mozilla.org/r/212386/diff/1-2/

Comment on attachment 8942124 [details] Bug 1430037 - Use sparse checkouts for docker image builds. Review request updated; see interdiff: https://reviewboard.mozilla.org/r/212388/diff/1-2/

Comment on attachment 8942123 [details] Bug 1430037 - Use the in-tree image builder image to build docker images. Review request updated; see interdiff: https://reviewboard.mozilla.org/r/212386/diff/2-3/

Comment on attachment 8942124 [details] Bug 1430037 - Use sparse checkouts for docker image builds. Review request updated; see interdiff: https://reviewboard.mozilla.org/r/212388/diff/2-3/