When TaskCluster builds a push to a Gecko repository, it does so in a docker image defined in that very push.
This is pretty cool for developers concerned with the build or test environment: instead of working with releng to deploy a change, now you can experiment with that change in try, get review, and land it like any other change.
However, if you want to actually download that docker image, docker pull doesn’t work anymore.
The image reference in the task description looks like this now:
"image": {
"path": "public/image.tar",
"taskId": "UDZUwkJWQZidyoEgVfFUKQ",
"type": "task-image"
},
This is referring to an artifact of the task that built the docker image. If you want to pull that exact image, there’s now an easier way:
./mach taskcluster-load-image --task-id UDZUwkJWQZidyoEgVfFUKQ
will download that docker image:
dustin@dustin-moz-devel ~/p/m-c (central) $ ./mach taskcluster-load-image --task-id UDZUwkJWQZidyoEgVfFUKQ
Task ID: UDZUwkJWQZidyoEgVfFUKQ
Downloading https://queue.taskcluster.net/v1/task/UDZUwkJWQZidyoEgVfFUKQ/artifacts/public/image.tar
######################################################################## 100.0%
Determining image name
Image name: mozilla-central:f7b4831774960411275275ebc0d0e598e566e23dfb325e5c35bf3f358e303ac3
Loading image into docker
Deleting temporary file
Loaded image is named mozilla-central:f7b4831774960411275275ebc0d0e598e566e23dfb325e5c35bf3f358e303ac3
dustin@dustin-moz-devel ~/p/m-c (central) $ docker images
REPOSITORY TAG IMAGE ID CREATED VIRTUAL SIZE
mozilla-central f7b4831774960411275275ebc0d0e598e566e23dfb325e5c35bf3f358e303ac3 51e524398d5c 4 weeks ago 1.617 GB
But if you just want to pull the image corresponding to the codebase you have checked out, things are even easier: give the image name (the directory under testing/docker), and the tool will look up the latest build of that image in the TaskCluster index:
dustin@dustin-moz-devel ~/p/m-c (central) $ ./mach taskcluster-load-image desktop-build
Task ID: TjWNTysHRCSfluQjhp2g9Q
Downloading https://queue.taskcluster.net/v1/task/TjWNTysHRCSfluQjhp2g9Q/artifacts/public/image.tar
######################################################################## 100.0%
Determining image name
Image name: mozilla-central:f5e1b476d6a861e35fa6a1536dde2a64daa2cc77a4b71ad685a92096a406b073
Loading image into docker
Deleting temporary file
Loaded image is named mozilla-central:f5e1b476d6a861e35fa6a1536dde2a64daa2cc77a4b71ad685a92096a406b073