How to delete a Docker container?

Docker containers consume space and resources on your host system. By removing unnecessary containers, you can free up valuable storage space and improve your system performance.

When should you delete a Docker container?

Docker containers are isolated executable units which contain applications and their dependencies. Removing Docker containers can be done in a variety of scenarios to keep your Docker environment efficient, secure, and clear.

Generally speaking, you should remove containers after their use. When a container has successfully completed its specific task or process, it is advisable not to keep it in your environment any longer. This prevents inactive containers from continuing to tie up resources and take up space unnecessarily.

It's also a good idea to delete containers that are no longer in use or haven't received updates in a while. This is particularly important for reduce security risksbecause older containers may have outdated software versions or security vulnerabilities.

If you have any doubts about the security of a container or think it might be compromised, delete it immediately to minimize risk. The same goes for containers that cannot be started due to conflicts or other issues.

Deleting one or more specific Docker containers is a common procedure to remove unnecessary or inactive containers from Docker host.

Step 1: Determine the Container ID or Name

You must first find the Container IDs or names that you want to delete. You can use the following command to display a list of all running or stopped containers:

Step 2: Remove Containers

You can simply provide space-separated container ids or names after the command docker rm :

docker rm container_id_or_name1 container_id_or_name2

Delete a container on close

To automatically delete a Docker container when it closes, place the option (flag) --rm when you start the container with the command docker run. This option allows the container to be automatically deleted as soon as it is stopped.

docker run --rm nom_image

It is also possible to delete all completed containers at once, by filtering the containers according to their status and deleting them with rm.

Step 1: List Completed Containers

The option -f status=exited allows you to filter the list of containers to display only those that are completed.

docker ps -a -f status=exited

Step 2: Delete Completed Containers

The previous step allows you to obtain the identifiers of the completed containers in order to transmit them directly to the command docker rm.

docker rm $(docker ps -a -f status=exited -q) 

Delete containers with more than one filter

You can delete Docker containers with more than one filter by applying the command docker ps in combination with filter optionsthen passing the output to the command docker rm.

Step 1: List Containers with Filters

The command docker ps with filter options allows you to list containers based on the desired criteria. “created” is, along with “exited”, another selectable state. Containers as is created are those that have been created but not yet executed.

docker ps -a -f status=exited -f status=created 

Step 2: Remove Docker Containers

As in the previous example, you must transmit the result to the command docker rm.

docker rm $(docker ps -a -f status=exited -f status=created -q)

The method involves finding all Docker containers that match a particular pattern and then deleting them with awk, xargs And docker rm. This technique is a powerful way to selectively delete containers.

Step 1: Find All Containers with a Pattern

If you use the command docker ps -a in combination with grep, you will get all the containers whose name or tags match a specific model. For example, this command lists containers whose name begins with “test-”:

docker ps -a | grep "test-" 

Step 2: Remove Docker Containers

The command awk allows you to select specific columns in output result. In this case, the objective is to extract the first column, which contains the container identifiers. Then we can use xargs to transmit the identifiers to the order docker rmi and delete Docker containers.

docker ps -a | grep "test-" | awk '{print $1}'. | xargs docker rmi

You can stop and delete all active and inactive containers from your system at once. This can be useful if you want to perform a complete cleaning of your Docker environment.

Step 1: List Containers

To check the list of containers, type the following command:

Step 2: Stop Containers

Once you have made your decision, transfer the output from the previous step to docker stop. This will stop all containers.

docker stop $(docker ps -a -q)

Step 3: Remove Stopped Docker Containers

Once all containers have been stopped, you can delete them with the command docker rm :

docker rm $(docker ps -a -q)

Unlike normal Docker containers, Docker container volumes are mechanisms with which data can be persisted and exchanged between containers and the host system. You can find more tutorials on how to delete a Docker volume or Docker image in our guide.