add go-max-procs annotation

[packageman]

When Golang program started in a container, the P (from Golang GMP model) will be set to the number of CPU cores of host instead of container's CPU limit (cgroups).

Assuming vault-agent sidecar is deployed on a 16core64g machine, the P of vault-agent will be set to the number of CPU cores by default, which is 16, and the available CPU of the vault-agent is 500m (helm chart default setting), which will cause the CPU to be used too high constantly. Solved by explicitly setting GOMAXPROCS to 1.

Therefore, add annotation vault.hashicorp.com/go-max-procs to support configuring P's number accordingly.

• P = 16

• P = 1

[hashicorp-cla]

All committers have signed the CLA.

[tvoran]

Thanks for the analysis here! This looks pretty straightforward, but would you mind testing for that variable in agent-inject/agent/container_env_test.go?

[packageman]

@tvoran tests added.

[swenson]

LGTM. I pulled this down and tested it, and it seems to work as expected. Thanks!