Clear docker cache linux

Содержание

Cleaning local docker cache
Solution
Removing unused containers
Removing all containers
Removing dangling images
Removing all images
Removing volumes
Removing networks
Removing everything
References
docker clear cache with code examples
Popular questions
Tag

Cleaning local docker cache

Recently, my laptop was running out of space. I had the impression that docker would be the culprit and went to check its disk space usage, using the following command:

It turns out that Docker was consuming close to 40% of the disk space available!

Solution

Let’s go through the different options to free hard disk space.

Removing unused containers

Docker containers have a status field indicating where they are at in their lifecycle. According to the docs, status can be one of created , restarting , running , removing , paused , exited , or dead .

First, we need to get the IDs of the containers with status exited or dead as follows:

docker ps --filter status=exited --filter status=dead -q

Then, we can reuse the above command to delete these containers with the following command:

docker rm $(docker ps --filter=status=exited --filter=status=dead -q)

A one-liner alternative to remove all stopped containers is:

Removing all containers

First, we need to stop all running containers. We can get the IDs of the running containers as follows:

Then, we can stop all the containers with:

You can replace docker stop with docker kill in the above command to forcibly stop the containers.

Finally, we can delete all containers:

Removing dangling images

Dangling images, as mentioned by the documentation, are final images (i.e, not intermediary build layers) that no longer have an associated tag with them.

We can get the image ID for such images as follows:

docker images --filter dangling=true -q

Then, we can delete those images with the following command:

docker rmi $(docker images --filter dangling=true -q)

A one-liner alternative to remove all dangling images is:

Removing all images

Docker doesn’t allow to remove images that have an associated container, so to really delete all images, it is necessary first to remove all containers.

Similarly to the previous section, we need the IDs of all the images, which we can get using:

Then, we can combine it with docker rmi :

docker rmi $(docker images -a -q)

A one-liner alternative to remove all images is:

Removing volumes

Volumes also take space in the host machine. They are never deleted automatically since they may contain data that can be reused by different containers or directly from the host.

Then, to remove all docker volumes use:

Removing networks

Although docker networks don’t consume too much disk space, they create iptables rules, network devices and routing table entries. To prune these objects, you can run:

Removing everything

Instead of manually pruning different types of resources, you may be interested on wiping out everything from your local cache. For that we can leverage the docker system prune command as follows:

To remove containers, images and networks use:

To remove containers, images, networks and volumes, use

docker system prune --volumes

References

docker ps command
docker rm command
docker images command
docker rmi command
docker container prune command
docker image prune command
docker volume prune command
docker network prune command
docker system prune command
Prune unused Docker objects
Docker Forum — How to delete cache

Disclaimer: The opinions expressed herein are my own personal opinions and do not represent my employer’s view in any way.

Источник

docker clear cache with code examples

D ocker is a popular platform for containerization and is widely used in the development and deployment of applications. Docker uses a cache mechanism to store images and layers for faster image retrieval and deployment. However, sometimes the cache can become outdated, or you may want to free up disk space. In such cases, you can clear the Docker cache. This article will show you how to clear the Docker cache using code examples.

There are two main ways to clear the Docker cache:

This command will remove all unused containers, networks, images, and volumes. It will also free up disk space used by Docker.

This command will remove a specific image. Replace with the ID of the image you want to remove.

You can also remove multiple images at once:

It is important to note that removing an image will also remove its associated containers, networks, and volumes.

In addition to these basic commands, you can also use the following command to clear the Docker cache:

This command will remove all unused images.

It is also possible to clear the cache of a specific image:

This command will remove the specified image and its associated containers, networks, and volumes.

In conclusion, clearing the Docker cache is a simple and straightforward process. You can use the docker system prune command to remove all unused containers, networks, images, and volumes, or the docker rmi command to remove a specific image. The docker image prune command can also be used to clear the cache of all unused images or a specific image. These commands will help you free up disk space and keep your Docker environment clean and efficient.
In addition to clearing the Docker cache, there are a few other related topics that are worth discussing.

Docker images are built from multiple layers, and each layer represents a change made to the image. When you run a container, Docker will use the cached layers to speed up the deployment process. However, if you make changes to the image and build a new version, the old layers will remain in the cache, taking up valuable disk space. Clearing the cache regularly can help you free up disk space and keep your Docker environment efficient.

Docker volumes are a way to persist data generated by containers, even after the containers are deleted. Volumes can be created and managed using the docker volume command. By default, Docker volumes are stored on the host file system, and can take up a significant amount of disk space over time. You can use the docker system prune command to remove unused volumes and free up disk space.

Docker networking is a powerful feature that allows you to connect containers to each other and to the host network. By default, Docker creates a default network for each host, but you can also create custom networks using the docker network command. When you remove a container, its associated network interfaces are also removed. However, the networks themselves are not removed unless you explicitly remove them using the docker network rm command.

Docker Compose is a tool for defining and running multi-container Docker applications. With Compose, you can define your application’s services, networks, and volumes in a single file, and then use a single command to start and stop the entire application. Compose can also be used to scale services, manage containers, and configure network connections.

In conclusion, clearing the Docker cache is just one aspect of managing a Docker environment. By understanding the concepts of image layers, volumes, networking, and Compose, you can create and manage Docker applications more effectively and efficiently.