Merge "etcdmain: fix ignoring of ETCD_CONFIG_FILE env variable" into 3.3 branch?

[kallisti5]

In #10747 , passing ETCD_CONFIG_FILE as an environment variable doesn't work as expected.
A fix was accepted into master in ea70731 (with doc updates later accepted as well, #10762)

Can this be merged for inclusion into 3.3.14 ? (unless 3.4 is planned soon?)

This issue prevents easily deploying an etcd cluster in docker swarm with compose. (You can go - template out node replica numbers in environment vars, but not in command line variables)

Since this is a "can't even run" issue, it would be nice to get it in sooner than later. The risks are low as well since it is "just fixing existing code paths"

[jingyih]

cc @gyuho who is the 3.3 release manager.

I think this is a bug fix and should be backported.

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed after 21 days if no further activity occurs. Thank you for your contributions.

[EugenKon]

Very sad, that so important issues are automatically closed without care =(