🇬🇧 How To Remove Docker Images, Containers, Networks & Volumes
https://phoenixnap.com/kb/remove-docker-images-containers-networks-volumes
Dernière mise à jour
https://phoenixnap.com/kb/remove-docker-images-containers-networks-volumes
Dernière mise à jour
Docker containers are designed to provide a self-sufficient environment, with all the libraries and configurations needed for the software to execute. During development, they can grow unorganized with old, outdated, and unused components.
In this guide, you will learn how to organize a Docker environment by removing Docker images, containers, volumes, and networks.
Using these commands makes Docker container management fast and straightforward.
Linux system running Docker
Access to a terminal/command line (Ctrl+Alt+T on Ubuntu, Alt+F2 on CentOS)
User account with sudo privileges
Note: If your system responds with “access denied” after trying to remove, add the sudo prefix at the beginning of the command.
A container creates a specific environment in which a process can be executed. Many containers are created, tested, and abandoned during the development lifecycle.
Therefore, it’s important to know how to find unnecessary containers and remove them.
1. First, list all Docker containers using the command:
The output displays a list of all running containers, their IDs, names, images, status and other parameters.
You can also generates a list of all the containers only by their numeric ID’s, run the command:
2. To stop a specific container, enter the following:
Replace [container_id] with the numeric ID of the container from your list.
You can enter multiple container IDs into the same command.
To stop all containers, enter:
This forces Docker to use the list of all container IDs as the target of the stop command.
Note: If you are logged in as the sudo user, make sure to add the sudo prefix before both docker commands when stopping all containers ( sudo docker container stop $(sudo docker container ls –aq) )
To remove a stopped container, use the command:
Like before, this removes a container with the ID you specify.
To remove all stopped containers:
To wipe Docker clean and start from scratch, enter the command:
This instructs Docker to stop the containers listed in the parentheses.
Inside the parentheses, you instruct Docker to generate a list of all the containers with their numeric ID. Then, the information is passed back to the container stop command and stops all the containers.
The && attribute instructs Docker to remove all stopped containers and volumes.
–af indicates this should apply to all containers (a) without a required confirmation (f).
You can also specify to delete all objects that do not match a specified label.
To do so, use the command:
This command tells Docker to remove all containers that are not labeled with a maintainer of “jeremy.” The != command is a logical notation that means “not equal to.”
A breakdown of the label commands:
label=
label==
label!=
label!==
Using these terms in conjunction with labels gives you in-depth control over removing assets in Docker.
Docker images are files, which include multiple layers used to run code within a container.
Images may go through many iterations during development. Old and outdated images can clutter your system, taking up storage space and making searches more cumbersome.
1. To remove a Docker image, start by listing all the images on your system:
The output displays the locally available Docker images, as seen below.
2. Make a note of the IMAGE ID – this is the identifier used to remove the image.
3. Then, remove the unwanted image(s):
Replace [image_id1] and [image_id2] with the image ID you pulled from the first command. You can enter a single Image ID, or multiple IDs for removal.
The system may respond to your request with an error message, that there is a conflict and it is unable to remove the repository reference. This indicates that a container is using the image. You need to remove the container first before you can remove the image.
At the time of publication, the only supported filters are until and label. Still, these are powerful tools for managing Docker resources.
Use the until filter to remove all resources up to a given time.
Enter the following:
This removes all (–a) images created over the last 24 hours. The command can be used for containers, images, and filters. Make sure to specify the asset you want to remove.
The until command accepts Unix timestamps, date-formatted timestamps, or an amount of time (30m, 4h, 2h25m) calculated against the machine time.
Use the label command to remove assets defined by labels.
Enter the following:
This removes all docker images that have been labeled “old”.
Filtering can also be used to define a specific value of a label.
For example, if a container is labeled with a “maintainer” key, and the value of “maintainer” is either “bill” or “jeremy,” you can type:
Docker then removes all containers with the label “maintainer” with a value of “bill.”
A volume is used to store Docker data.
It helps store and organize data outside containers in a way that it’s accessible to multiple containers.
1. Use the following command to generate a list of all the available Docker volumes:
Take note of the VOLUME NAME you want to remove.
2. Then enter:
Make sure to replace VolumeName with the actual name you generated with the previous command.
If the volume is in use by an existing container, the system responds with an error. This means need to remove the container first.
Docker networks allow different containers to communicate with each other freely while also preventing traffic from outside the network. This is typically done with a Docker bridge network.
The prune command removes all unused networks.
1. Display a list of all existing Docker networks with the command:
2. Take note of the NETWORK ID – this is the identifier used to remove a specific network. Then, enter:
Replace [networkID] with the ID you captured from the first command.
You may receive an error message that says the network has active endpoints. That means that the network is currently in use by containers. You need to remove the containers that are using the network before you can remove the network.
The prune command automatically removes all resources that aren’t associated with a container. This is a streamlined way to clean up unused images, containers, volumes, and networks.
In a terminal window, enter the following:
Additional flags can be included:
–a To include stopped containers and unused images
–f Bypasses confirmation dialog
––volumes Removes all unused volumes
Also, you can specify a single type of object to be removed, instead of the entire environment:
Running docker system prune -a removes both unused and dangling images . Images used in a container, either currently running or exited, will NOT be affected.
Enter the following commands to display resources:
The above-mentioned lists number of containers, images, and information about the Docker installation. These commands can help you locate and identify resources that you want to keep, or that you want to delete.
The following flags can also be added:
–a display all of a resource (including the ones that are stopped)
–q or --quiet (display only the numeric ID)
During the development cycle of an application in Docker containers, it’s easy to use a lot of storage with old versions of images and containers.
In this guide, you learned the most common commands for removing Docker images, containers, volumes, and networks.
