exec Interactive is Not a Login ShellYou probably want the following instead of just exec bash:
docker exec -it <container> bash -c "su - <user>"
Most people will never care that exec -it does not provide a login
shell. But if you ever want to create a working container image that you
commit regularly and use to create a consistent working environment then
you will really care about this difference. I’ve been burned by
forgetting this. There are a couple ways to check for this:
echo $0 will be -bash (the hyphen is the giveaway)$USER will be setI discovered this because a login script that we use at work failed
because it was detecting $USER which wasn’t there. Had that not
happened I would never have known that this isn’t a login shell. There
certainly is zero documentation on that fact.
What’s worse is that I missed this distinction before because I was
exec-ing in as root to set it up and su - <user> to get the user,
which always provides a login shell (that’s what the - does).