[feature] Add tini to Telegraf Docker Image

[trastle]

This has been discussed previously however I believe it's possibly worth another consideration.

I am running Telegraf in Kubernetes this makes the Docker --init flag discussed influxdata/telegraf#2820 in not an option. Kubernetes has no awareness of this Docker specific feature.

I am seeing the same problem described in influxdata/telegraf#2476 however I am using the current latest Telegraf container.

I acknowledge this is not a bug in Telegraf. This is a limitation of running as PID 1 in a Docker container. Given the Telegraf Docker container has more than 100 million pulls, there are clearly a lot of folk running Telegraf this way.

I believe adding tini into the container would be a net benefit as it will assist in avoiding this issues which was first raised over 3 years ago.

If the Telegraf team would entertain the PR I would be happy to make it.

Past Issues

• [BUG] Timed out scripts launched by exec plugin become zombies telegraf#2476
• Consider reaping orphans if pid 1 telegraf#2820
• Telegraf docker image should use init system as an entrypoint #66

[trastle]

Adding this Stack Overflow ref as it is relevant to the discussion and gives a good description https://stackoverflow.com/questions/50803268/kubernetes-equivalent-of-docker-run-init

[reimda]

@trastle I think adding tini is a good idea. Thanks for offering to put together a PR. If you're still available to do it, that would be great. I or someone else on the team will review it.