Estimated reading time: 4 minutes
Last updated on November 8th, 2024 at 04:50 pm
Docker provides the tools to create, deploy, and run the application inside the container.
Docker containers are isolated and run in the background, accessing the Docker container shell allows you to do the troubleshooting, debugging, and execute commands inside.
Let’s explore how to enter Docker Container Shell with a simple troubleshooting guide.
Table of Contents
Methods to Enter Docker Container Shell
Docker provides various ways to enter Docker container shell, regardless of whether you want to connect to an existing container or run it for the first time.

1. Using Docker Exec Command
You can connect to the running container using docker exec
the command.
The docker exec
the command allows you to enter the Docker container shell with one exception: the container should be running.
Let’s run the nginx
container to showcase:
docker run --name nginx_exec nginx
Now the container is up and running but let’s verify the container status before, in case you have the container already running:
# Verify the running container
docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
752efsfd9fes nginx "/bin/bash" 17 seconds ago Up 22 seconds nginx_exec
The Nginx container is up and running in the background let’s enter Docker container shell in Nginx.
# Using container name
docker exec -it nginx_exec bash
# Using container id
docker exec -it 752efsfd9fes bash
Syntax: docker exec -it <container_name_or_id> <shell>
Let’s understand this command:
docker exec
execute the command inside the Docker container-it
flag is used to indicate the Docker to open the interactive terminal withSTDIN
- Lastly, you can pass the container name or container ID as a target.
In this example, you can see, that Docker provides an easy-to-use docker exec command to open the Docker container shell. But it only works when the container is running.
So if you want to debug and enter the Docker container shell you need to keep the Docker container alive and running.
2. Interactive Mode during Container Run
Sometimes you want to interact with the container immediately as soon as it runs for scenarios like debugging or manual configuration.
Docker provides a way to run the container directly with an interactive mode:
docker run -it --name nginx_interative nginx bash
Syntax: docker run -it <image_name> <shell>
Let’s understand this command:
docker run
allows to run the container with an additional flag-it
flag indicates the Docker to open the interactive terminal withSTDIN
after it starts running.- Once the container is running, you will have a bash shell running inside the container.
3. Attach to Running Container
You can attach your terminal’s standard input, output, and error to the running Docker container with docker attach
.
Let’s attach to an already running container nginx:
docker attach nginx_exec
Once you run this command, signals are transferred to the attached process. You can check the details about Attaching and Detaching From a Docker Container.
4. Docker Debug ( Beta )
Docker Debug is another way to enter Docker container shell.
However, this feature is still in beta and not recommended in the production environment. Docker Debug is unavailable in the community version you need a Pro, Team, or Business subscription.
docekr debug
command follow the best security practices and keep Docker image small and secure. With Docker Debug support for bash
, fish
and zsh
and provides the Linux tools pre-installed, vim
, nano
, htop
, and curl
docker debug nginx_exec
Let’s verify the filesystem:
docker > ls
dev etc hello nix proc sys
Conclusion:
Accessing the shell inside the Docker container is necessary for troubleshooting containerized applications. In this blog, we explored the 4 simple methods to enter Docker container shell with syntax and use case, you can choose the appropriate method based on your specific requirements.
Checkout the below guide for additional Docker troubleshooting.
Troubleshooting Resouces Docker:
Docker Container Security Cheatsheet
“No Space Left On Device” In Docker
How to Keep Docker Container Running For Debugging
How to Attach and Detach From a Docker Container