CODEWITHSUNDEEP
docker
Arel Lin
Arel Lin

Reputation: 928

What's the difference between docker exec and docker exec -it?

I am new to Docker. I was trying to implement MySQL using Docker container.

When it comes to executing mysql command in Docker container, the tutorial shows this command docker exec -it mysql1 mysql -uroot -p

Docker document mentioned docker exec means run a command in container .
The optional i tag means "Keep STDIN open even if not attached" .
The optional t tag means "allocate a pseudo tty" .

What means "Keep STDIN open", what means "attached"?
What means "allocate a pseudo tty"?

I'm not familiar with shell commands. I don't know why '-it' should be added here.
Will it be different if I just type docker exec mysql1 mysql -uroot -p?

So confused, looking forward to any help... thanks...

Upvotes: 12

Views: 6438

Answers (2)

jar
jar

Reputation: 2908

Will Cain's answer is more complete, but in short, giving -it lets you get inside the container in interactive mode i.e -
-t : Allocate a pseudo-tty
-i : Keep STDIN open even if not attached

Docs for docker run that explains those arguements.

NOTE: docer exec is for running a command inside an already running container. Hence it is extremely useful for debugging conatiners.

Upvotes: 1

Will
Will

Reputation: 7057

-i -- Don't just run the program in the background with no way to send it data; keep it open to accepting input of some form.

-t -- Specifically, give me a place to type commands to send to the program, as if I had an ssh or telnet session open to a remote machine I could feed commands to.

Together they essentially make it so that you can run e.g. your mysql1 program as if you were just running it normally locally, outside a Docker container.

Upvotes: 18

Related Questions