How can I delete containers by using docker?

171 Asked by ClaudineTippins in Devops , Asked on Jul 1, 2024

I am currently engaged in a particular task that is related to managing a docker-based environment and suddenly I have noticed that my server is running out of disk space. When I investigated, I found that many stopped containers are consuming space. How can I use docker to delete these stopped containers so that I can free up the space in my server?

Answered by David

In the context of DevOps, if you want to delete the stopped containers in the docker and want to free up disk space, then you can use the following command:

“docker container prune”

Explanation

Identifying stopped containers

Firstly, you would need to list all the containers and then identify the ones that are stopped by using :

  “docker ps- a”

Removing stopped containers

Now you can remove all the stopped containers by using

  “docker container prune”

Force removal

If you want to avoid the confirmation prompt so that you can forcibly delete then you can use the -f flag

  “docker container prune -f”

Here is a java based approach given:-

Creating java program

Import com.github.dockerjava.api.DockerClient;

Import com.github.dockerjava.api.model.Container;

Import com.github.dockerjava.core.DockerClientBuilder;

Import com.github.dockerjava.core.DockerClientConfig;

Import com.github.dockerjava.core.DefaultDockerClientConfig;

Import com.github.dockerjava.httpclient5.ApacheDockerHttpClient;

Import com.github.dockerjava.transport.DockerHttpClient;

Import java.util.List;

Public class DockerContainerManager {

    Public static void main(String[] args) {

        // Docker daemon connection configuration

        DefaultDockerClientConfig config = DefaultDockerClientConfig.createDefaultConfigBuilder()

                .withDockerHost(“unix:///var/run/docker.sock”) // Adjust if your Docker daemon runs on a different host

                .build();

        DockerHttpClient httpClient = new ApacheDockerHttpClient.Builder()

                .dockerHost(config.getDockerHost())

                .build();

        DockerClient dockerClient = DockerClientBuilder.getInstance(config)

                .withDockerHttpClient(httpClient)

                .build();

        Try {

            // List all containers including stopped ones

            List containers = dockerClient.listContainersCmd().withShowAll(true).exec();

            For (Container container : containers) {

                System.out.println(“Container ID: “ + container.getId());

                System.out.println(“Status: “ + container.getStatus());

                // Check if the container is stopped

                If (container.getStatus().startsWith(“Exited”)) {

                    System.out.println(“Container “ + container.getId() + “ is stopped.”);

                } else {

                    System.out.println(“Container “ + container.getId() + “ is running.”);

                }

            }

        } finally {

            // Close the Docker client

            dockerClient.close();

        }

    }

}

Listing all the containers

Import com.github.dockerjava.api.DockerClient;

Import com.github.dockerjava.api.model.Container;

Import com.github.dockerjava.core.DockerClientBuilder;

Import com.github.dockerjava.core.DockerClientConfig;

Import com.github.dockerjava.core.DefaultDockerClientConfig;

Import com.github.dockerjava.httpclient5.ApacheDockerHttpClient;

Import com.github.dockerjava.transport.DockerHttpClient;

Import java.util.List;

Public class DockerContainerManager {

    Public static void main(String[] args) {

        // Docker daemon connection configuration

        DefaultDockerClientConfig config = DefaultDockerClientConfig.createDefaultConfigBuilder()

                .withDockerHost(“unix:///var/run/docker.sock”) // Adjust if your Docker daemon runs on a different host

                .build();

        DockerHttpClient httpClient = new ApacheDockerHttpClient.Builder()

                .dockerHost(config.getDockerHost())

                .build();

        DockerClient dockerClient = DockerClientBuilder.getInstance(config)

                .withDockerHttpClient(httpClient)

                .build();

        Try {

            // List all containers including stopped ones

            List containers = dockerClient.listContainersCmd().withShowAll(true).exec();

            For (Container container : containers) {

                System.out.println(“Container ID: “ + container.getId());

                System.out.println(“Status: “ + container.getStatus());

                // Check if the container is stopped

                If (container.getStatus().startsWith(“Exited”)) {

                    System.out.println(“Container “ + container.getId() + “ is stopped.”);

                } else {

                    System.out.println(“Container “ + container.getId() + “ is running.”);

                }

            }

        } finally {

            // Close the Docker client

            dockerClient.close();

        }

    }

}

Checking status and  remove stopped containers

Import com.github.dockerjava.api.DockerClient;

Import com.github.dockerjava.api.model.Container;

Import com.github.dockerjava.core.DockerClientBuilder;

Import com.github.dockerjava.core.DockerClientConfig;

Import com.github.dockerjava.core.DefaultDockerClientConfig;

Import com.github.dockerjava.httpclient5.ApacheDockerHttpClient;

Import com.github.dockerjava.transport.DockerHttpClient;

Import java.util.List;

Public class DockerContainerManager {

    Public static void main(String[] args) {

        // Docker daemon connection configuration

        DefaultDockerClientConfig config = DefaultDockerClientConfig.createDefaultConfigBuilder()

                .withDockerHost(“unix:///var/run/docker.sock”) // Adjust if your Docker daemon runs on a different host

                .build();

        DockerHttpClient httpClient = new ApacheDockerHttpClient.Builder()

                .dockerHost(config.getDockerHost())

                .build();

        DockerClient dockerClient = DockerClientBuilder.getInstance(config)

                .withDockerHttpClient(httpClient)

                .build();

        Try {

            // Example: List all containers

            listContainers(dockerClient);

            // Example: Check container status and perform action

            checkAndActOnContainers(dockerClient);

        } finally {

            // Close the Docker client

            dockerClient.close();

        }

    }

    // Example method: List all containers

    Private static void listContainers(DockerClient dockerClient) {

        List containers = dockerClient.listContainersCmd().exec();

        For (Container container : containers) {

            System.out.println(“Container ID: “ + container.getId());

            System.out.println(“Image: “ + container.getImage());

            System.out.println(“Status: “ + container.getStatus());

            System.out.println(“---------------------“);

        }

    }

// Example method: Check container status and perform action

    Private static void checkAndActOnContainers(DockerClient dockerClient) {

        List containers = dockerClient.listContainersCmd().exec();

        For (Container container : containers) {

            String containerId = container.getId();

            String status = container.getStatus();

            If (status.startsWith(“Exited”)) {

                // Container is stopped, perform action (e.g., remove container)

                System.out.println(“Container “ + containerId + “ is stopped. Removing…”);

                // Remove container

                dockerClient.removeContainerCmd(containerId).exec();

                System.out.println(“Container “ + containerId + “ removed.”);

            } else if (status.startsWith(“Up”)) {

                // Container is running, perform other actions as needed

                System.out.println(“Container “ + containerId + “ is running.”);

                // Add other actions here based on container status

            } else {

How can I delete containers by using docker?

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