How to SSH into a Docker Container

Docker containers do not run an SSH server by default. Normally you open a shell with docker exec. This is safer than adding SSH to a container.

What you need

• Docker installed (here on Ubuntu).
• A running container.
• Basic command line skills.

Method 1: docker exec (recommended)

Step 1: Find the container ID

docker ps

Step 2: Open a shell

docker exec -it 4d279546e295 /bin/bash

You can use the container name instead of the ID. If the image has no bash (like Alpine), use /bin/sh.

If you run an SSH server inside the container, you can connect to it like to any other machine:

ssh user@container-ip

Method 2: docker attach

docker attach connects your terminal to the main process of the container.

Step 1: Create a container

docker run --name attach-test -dit ubuntu

Step 2: Attach to it

docker attach attach-test

Method 3: Docker Compose with an SSH server

If you really need SSH, install and start an SSH server in the container. For a test, edit docker-compose.yml:

services:
  myservice:
    image: ubuntu
    command: /bin/bash -c "apt-get update && apt-get install -y openssh-server && mkdir -p /run/sshd && /usr/sbin/sshd -D"
    ports:
      - "2222:22"

You also need a user with a password or a key inside the container.

Deploy it

sudo docker compose up -d

Connect with the mapped port

ssh username@localhost -p 2222

(Use the host port from the ports line, here 2222, not 22.)

For a Compose service you can also use docker compose exec myservice bash, which needs no SSH server.

Method 4: docker run

Start a new container and open its shell at once:

docker run --name run-test -it nginx /bin/bash

This starts Bash instead of Nginx. When you type exit, the container stops.

Which method to use

• docker exec -it for a running container. This is the standard way.
• docker run -it for a new, temporary container.
• Avoid SSH servers in containers. They add a security risk and extra work.

FAQ

How can I get into a container? Use docker exec -it NAME /bin/bash.

Can I use SSH? Yes, but you must install and secure an SSH server in the container. It is not recommended.

Quick recap

• docker ps, then docker exec -it ID /bin/bash.