Description

Reduce Kubernetes resource size (when using agent-stack-k8s) by applying more environment variables from the socket.

Context

A customer had feedback that having a lot of env vars repeated across containers in the pod spec can consume a lot of space in etcd.

Changes

• Add a kubernetes-bootstrap subcommand. This allows fetching the env vars from the socket before the bootstrap subcommand runs, which was the fatal flaw in commit 36940e5
• Filter out the kubernetes plugin when creating the bootstrap env
• Some small-scale refactoring of flags and env helpers

Testing

• Tests have run locally (with go test ./...). Buildkite employees may check this if the pipeline has run automatically.
• Code is formatted (with go fmt ./...)