sourcegraph/cmd/executor
Peter Guy f8cc07220a
chore/executors: Native Kubernetes Executors default to use single job pod (#64088)
For Executors on Native Kubernetes deployments, the option to run jobs
in a single pod has been available since Native Kubernetes has been
around.

The purpose of running jobs in a single pod is:
1. Efficiency. Jobs require three steps at least, and without specifying
a single pod, that requires spinning up three pods.
2. Security. For Batch Changes, when jobs are run across several pods,
`git`'s `safe.directory` must be set to avoid untrusted users or
processes injecting code or an attack. Running the job in one pod
removes the need for `safe.directory`.
3. Usability. Because of the need to set `safe.directory`, `root` access
to write to `git`'s global config is required, which means that many
times special configurations and sign-offs from security teams must be
used for Batch Change setups.

This PR takes a step toward using single pod jobs only in enabling them
by default instead of requiring an environment variable to enable them.

The same environment variable that was used to enable them -
`KUBERNETES_SINGLE_JOB_POD` - is still available to disable them by
setting it to `false`.

## Test plan

Bazel and CI for now

## Changelog
2024-07-31 08:07:06 -07:00
..
docker-mirror release: never use build number in image family (#63157) 2024-06-07 17:23:24 +02:00
internal chore/executors: Native Kubernetes Executors default to use single job pod (#64088) 2024-07-31 08:07:06 -07:00
kubernetes chore/executors: Native Kubernetes Executors default to use single job pod (#64088) 2024-07-31 08:07:06 -07:00
vm-image release: never use build number in image family (#63157) 2024-06-07 17:23:24 +02:00
_binary.push.sh rfc795: new release process foundations (#60962) 2024-03-12 17:12:22 +01:00
BUILD.bazel bazel: transcribe test ownership to bazel tags (#62664) 2024-05-16 15:51:16 +01:00
ci-should-rebuild.sh ci: fix incorrect usage of target determinator (#59171) 2023-12-21 15:50:29 +00:00
image_test.yaml Move executor to cmd/executor (#55700) 2023-08-10 02:06:12 +02:00
main.go Docs: update links to point to new site (#60381) 2024-02-13 00:23:47 +00:00
README.md Port executors building/pushing scripts to use Bazel (#58892) 2023-12-20 18:33:49 +00:00

Executor

The executor service polls the public frontend API for work to perform. The executor will pull a job from a particular queue (configured via the envvar EXECUTOR_QUEUE_NAME), then performs the job by running a sequence of docker and src-cli commands. This service is horizontally scalable.

Since executors and Sourcegraph are separate deployments, our agreement is to support 1 minor version divergence for now. See this example for more details:

Sourcegraph version Executor version Ok
3.43.0 3.43.*
3.43.3 3.43.*
3.43.0 3.44.*
3.43.0 3.42.*
3.43.0 3.41.* 🚫
3.43.0 3.45.* 🚫

See the executor queue for a complete list of queues.

Building and releasing

Building and releasing is handled automatically by the CI pipeline.

Binary

The executor binary is simply built with bazel build //cmd/executor:executor.

For publishing it, see bazel run //cmd/executor:binary.push:

  • In every scenario, the binary will be uploaded to gcs://sourcegraph-artifacts/executors/$GIT_COMMIT/.
  • If the current branch is main when this target is run, it will also be copied over to gcs://sourcegraph-artifacts/executors/latest.
  • If the env var EXECUTOR_IS_TAGGED_RELEASE is set to true, it will also be copied over to gcs://sourcegraph-artifacts/executors/$BUILDKITE_TAG.

VM image

The VM Image is built with packer, but it also uses an OCI image as a base for Firecracker, //docker-images/executor-vm:image_tarball which it depends on. That OCI image is a legacy image, see docker-images/executor-vm/README.md.

Because we're producing an AMI for both AWS and GCP, there are two steps involved:

  • bazel run //cmd/executor/vm-image:ami.build creates the AMI and names it according to the CI runtype.
  • bazel run //cmd/executor/vm-image:ami.push takes the AMIs from above and publish them (adjust perms, naming).

While gcloud is provided by Bazel, AWS cli is expected to be available on the host running Bazel.

Building AMIs on GCP is rather quick, but it's notoriously slow on AWS (about 20m) so we use target-determinator to detect when to rebuild the image. See ci-should-rebuild.sh, which is used by the pipeline generator to skip building it if we detect that nothing changed since the parent commit.

Docker Mirror

As with the VM image, we're producing an AMI for both AWS and GCP, there are two steps involved:

  • bazel run //cmd/executor/docker-mirror:ami.build creates the AMI and names it according to the CI runtype.
  • bazel run //cmd/executor/docker-mirror:ami.push takes the AMIs from above and publish them (adjust perms, naming).

While gcloud is provided by Bazel, AWS cli is expected to be available on the host running Bazel.