Linux Tactic

Essential Docker Commands for Stopping and Listing Containers

Docker is a widely-used container platform that makes it easy to build, ship, and run distributed applications. Containers provide a way to package an application’s code, libraries, and dependencies, and can be deployed across different environments without any modifications.

Docker offers a range of powerful features that help users to manage and interact with containers, including stopping and listing running containers.

Stopping Docker Containers

Stopping a Single Docker Container

To stop a single Docker container, you need to use the command “docker stop” followed by the container ID or name. The container ID is a unique identifier generated by Docker when you start a container, while the container name is a user-defined alias for the container.

For example, to stop a container with ID “abc123”:

“`

$ docker stop abc123

“`

Or to stop a container with the name “webapp”:

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$ docker stop webapp

“`

Stopping Multiple Docker Containers

To stop multiple Docker containers at once, you can specify their IDs or names separated by a space:

“`

$ docker stop container1 container2 container3

“`

Alternatively, you can stop all running containers by omitting the container names:

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$ docker stop $(docker ps -q)

“`

Stopping All Containers with a Certain Image

If you want to stop all containers that were created from a specific image, you can use the “–filter” option with the “ancestor” parameter, followed by the image name:

“`

$ docker stop $(docker ps –filter “ancestor=image_name” -q)

“`

Stopping All Running Docker Containers

To stop all running Docker containers, you can use the following command:

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$ docker stop $(docker ps -aq)

“`

Gracefully Stopping a Docker Container

By default, Docker sends a SIGTERM signal to a container when you stop it, which allows the container to shut down gracefully. However, if the container is not responding to the SIGTERM signal, you can send a SIGKILL signal to force it to stop immediately:

“`

$ docker stop –signal=SIGKILL container_name

“`

Listing Running Docker Containers

Listing All Running Docker Containers

To list all running Docker containers, you can use the following command:

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$ docker ps

“`

This will show you a list of all running containers, along with their container ID, image, status, and other details.

Verifying if a Docker Container has Stopped

If you want to verify whether a Docker container has stopped or not, you can use the “-a” option to see all containers, not just the running ones:

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$ docker ps -a

“`

This will show you a list of both running and stopped containers, with their container IDs, image names, and other details.

Filtering Running Containers Based on Image

If you want to filter the list of running Docker containers based on their image, you can use the “-q” and “–filter” options:

“`

$ docker ps -q –filter ancestor=image_name

“`

This will show you a list of container IDs that were created from the specified image.

Conclusion

Overall, Docker provides a comprehensive set of tools for managing and interacting with containers, including stopping and listing running containers. By using these commands and options, you can easily stop or verify the status of a single container, multiple containers, or even all running containers.

Additionally, you can filter and manipulate the list of running containers based on their image or other criteria, making it easy to monitor and manage your Docker environment. Whether you’re new to Docker or an experienced user, understanding these commands and options is essential for effective container management.

When using Docker to manage containers, it’s important to be familiar with some additional information related to stopping Docker containers. Specifically, understanding the default grace period for the Docker stop command and how to change it can be helpful in ensuring proper container shutdown.

We’ll also touch on some future Docker tips and tutorials to help you get the most out of this powerful tool.

Default Grace Period for Docker Stop Command

When you use the Docker stop command to stop a running container, the default grace period before the container is forcibly stopped is 10 seconds. During this period, Docker sends the SIGTERM signal to the container, giving it a chance to shut down gracefully.

If the container does not stop within 10 seconds, Docker sends the SIGKILL signal to forcibly stop the container. The grace period is important to allow the processes running inside the container to clean up resources and exit cleanly.

This can prevent data corruption and other issues caused by abrupt container shutdown.

Changing Grace Period for Docker Stop Command

In some cases, you may need to adjust the grace period for the Docker stop command. For example, if you have a container with a complex shutdown process that requires more time to complete, you may want to increase the grace period to ensure a clean shutdown.

To change the grace period for the Docker stop command, you can use the “-t” option followed by the number of seconds for the grace period. For example, to set the grace period to 20 seconds:

“`

$ docker stop -t 20 container_name

“`

This will give the container 20 seconds to shut down gracefully before forcibly stopping it.

You can adjust the grace period as needed based on the specific requirements of your containers.

Conclusion and Future Docker Tips

Managing Docker containers can be complex, but understanding key commands and options like Docker stop is essential for smooth and efficient container management. By knowing how to stop and list running containers, adjust grace periods, and filter container lists based on image, you can effectively manage your container environment and avoid common issues caused by improper container shutdown.

In addition to these essential commands, there are many other aspects of Docker container management that can enhance your productivity and reduce downtime. Future Docker tips and tutorials might cover topics like container networking, managing container volumes, securing containers, and more.

By staying up to date with the latest Docker best practices and tools, you can stay ahead of the curve and make the most of this powerful and flexible container platform. In summary, the article discusses the essential Docker commands for stopping and listing running containers.

It also covers some additional information, such as the default grace period for the Docker stop command and how to change it. Proper container shutdown is critical for avoiding data corruption and other issues, so understanding these commands and options is vital for effective container management.

As Docker continues to evolve, staying up to date with the latest tips and tutorials can help you get the most out of this versatile tool. Ultimately, taking the time to learn Docker’s commands and features can help you work more efficiently, troubleshoot issues, and streamline your operations.

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