Set environment variables for host-containers

[vigh-m]

Discussed in #4315

^{Originally posted by dpavlov-smartling November 26, 2024}
Hello,

After checking the documentation, github issues and discussions I didn't find any native way to set environment variables for host-containers.
As of now, it seems that the only way is to specify the needed values in the host-container's user-data and then propagate them in the container's entrypoint.
My use case is monitoring of the instance including its metrics and logs:

1. To get Bottlerocket logs from journald I use custom Splunk container
2. To collect rest of the metrics I want to use Datadog

The reason for runnning them as a host-containers is to make sure that we have logs and metrics even if the instance hasn't joined the cluster.
This is for audit purpose.

The ability to add environment variables for host-containers would eliminate the need to create custom containers that can process user-data. Instead you would be able to use original container and configure it via environment variables.

Thanks,