CODEWITHSUNDEEP
dockercontainers
Grégori Fernandes de Lima
Grégori Fernandes de Lima

Reputation: 1454

Docker run command without -it option

Why when i run the command

docker run ubuntu

without option '-it' is not possible to interact with the created container even when running command start with the -a -i options

docker start -a -i CONTAINER_ID

or when i run

docker start CONTAINER_ID

simply the container has the status "Exit (0) 4 seconds ago"

But when i run

docker run -it ubuntu

i can use bash shell of ubuntu using 'docker start -a -i'

Upvotes: 0

Views: 7583

Answers (2)

codingwithmanny
codingwithmanny

Reputation: 1184

When you run docker run without -it it's still running the container but you've not given it a command, so it finishes and exits.

If you try:

docker run ubuntu /bin/bash -c "echo 'hello'";

It'll run ubunu, then the command, and then finish because there is no reason for it to be kept alive afterwards.

-i is saying keep it alive and work within in the terminal (allow it to be interactive), but if you type exit, you're done and the container stops.

-t is showing the terminal of within the docker container (see: What are pseudo terminals (pty/tty)?)

-it allows you to see the terminal in the docker instance and interact with it.

Additionally you can use -d to run it in the background and then get to it afterwards.

Ex:

docker run -it -d --name mydocker ubuntu;
docker exec -it mydocker /bin/bash;

Upvotes: 7

chenrui
chenrui

Reputation: 9886

TLDR is -it allows you connect a terminal to interactively connect to the container.

If you run docker run --help, you can find the details about docker run options.

$ docker run --help

Usage:  docker run [OPTIONS] IMAGE [COMMAND] [ARG...]

Run a command in a new container

Options:
  ...
  -i, --interactive                    Keep STDIN open even if not attached
  ...
  -t, --tty                            Allocate a pseudo-TTY

Upvotes: 1

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