| commit | ea0294266a933da0bda0916b1639fa49b512af1f | [log] [tgz] |
|---|---|---|
| author | Avi Kondareddy <avikr@google.com> | Fri Nov 16 18:33:00 2018 -0800 |
| committer | Avi Kondareddy <avikr@google.com> | Tue Nov 27 13:40:01 2018 -0800 |
| tree | 493ea7d498d7ebdfc13349435f3512ae3fc4c781 | |
| parent | 6aa564dac191cc832568230e4c769555f2efdb84 [diff] |
Adds Bazel Rules for building/pushing docker images Change-Id: If08c1cff4b1bc01a8fcf297c14e4d1c20cdbe263 Google-Bug-Id: 119838739 Signed-Off-By: Avi Kondareddy <avikr@google.com>
KUnit uses Prow for presubmit and CI.
This repository contains all the code and instructions needed for generating a docker container for building and running KUnit tests on Prow, and then using that container with a Prow cluster.
The official repo for Prow is test-infra, Kubernetes' test infrastructure. It enables us to run presubmit jobs on changes to our gerrit repo against an arbitrary docker container image. We have pushed the docker image generated from here to gcr.io/kunit-presubmit/kunit. The image is pulled and deployed by our prow cluster, source is pulled into working directory of container from kunit source, and entrypoint script (kunit.sh) is ran. The script copies kunitconfig to working directory, runs kunit.py, and sends output to job artifacts that can be viewed later. Prow will comment on the Gerrit change with the status of the job (successful, a test failed, a test crashed, etc) and link to Prow URL for more details. The container is currently configured to require the inclusion of kunitconfig in repo. A convenience of this model is that updating the job image can be done without change to ProwJob configuration.
The docker image is configured in the Dockerfile. It is based off of Debian, with kernel build tools installed and the script ran by the prowjob included. A couple peculiarities of building/running UML in a docker container are solved in the deployment configuration discussed below under “Prow Job Specification”.
To build and push, you can either use Bazel or Docker:
Bazel allows building/pushing without dependence on docker and automates using latest kunitconfig in build. As Bazel enforces deterministic builds, all debian packages depended on are listed in debs.bzl, and based off the snapshot specified in the dpkg_src rule in WORKSPACE.
The direct dependencies needed are:
If recursive dependancies change in future snapshots, debs.bzl must be manually updated with a list of all dependancies. A simple solution:
# run interactive shell in latest debian image docker run -it --rm debian # install direct dependancies apt install build-essential bc m4 flex bison python3 # generate list of all required dependancies recursively apt-cache depends --recurse --no-recommends --no-suggests --no-conflicts \ --no-breaks --no-replaces --no-enhances --no-pre-depends \ build-essential bc m4 flex bison python3 | grep "^\w" | sort -u
The snapshot used can be updated as specified in the distroless package manager bazel rules.
# build prowjob image bazel build :kunit # push to configured repo bazel run :push_kunit # build test image with kunit source and add to local docker bazel run :kunit_test # need docker to run, results to stdout docker run --privileged --tmpfs /dev/shm:exec kunit-presubmit/test:kunit_test
You must have Docker Make sure to enable sudoless docker (fixes gcr push authentication problems).
Now to build and push image :
# build image docker build . gcr.io/kunit-presubmit/kunit # confirm image is built docker images # push to gcr docker push gcr.io/kunit-presubmit/kunit
To test the container locally:
# have tmp directory with source checked out to $TMP/linux cp Dockerfile.test $TMP/Dockerfile cd $TMP # build test container which includes source docker build . -t test # run with args to handle issues with UML in Docker. docker run --privileged --tmpfs /dev/shm:exec test # extract log RUN=$(docker container ls --last 1 -q) docker cp $RUN:/artifacts/kunit.log . cat kunit.log # cleanup container docker rm $RUN
Note: Testing with an interactive shell results in unexpected behaviour. Running the UML Kernel in an entrypoint script works as intended but fails in an interactive shell.
By default, we have configured our install to use Google Container Registry. This requires installing Google Cloud SDK and configuring with project to push to. If using docker to push, you will need to enable gcloud authentication first to push with gcloud auth configure-docker.
Prow Jobs are detailed at testinfra/prow/jobs.md. The prow job specification is held in the config.yaml. It specifies the gerrit repo for prow to poll and the specifications for the container. We found that running the container privileged and mounting a emptydir at /dev/shm fixed KUnit build errors. There may be more secure methods, but as prow doesn't expose job containers to external resources, this solution results in the cleanest Dockerfile. We are using the decorated prow job which is recommended for all new prowjobs and detailed at test-infra/prow/pod-utilities.md.
The job script and kunitconfig stored inside in the docker image are kunit.sh and kunitconfig.
Prow sets the environment variable ARTIFACTS to specify a directory that will be exported to gcloud on job completion. It additionally sends all data send to stdout/stderr to the reporting interface. Exit code of 0 signals success and 1 signals failure akin to regular shell scripts.
TODO(avikr@google.com): add cluster.yaml and explain