How to List Docker Containers in Linux [5 Effective Methods]

Written by

Ojash

Reviewed by

Akshat

Last updated: July 26, 2023

Expert verified

Docker containers have revolutionized the world of software development, enabling developers to package applications with all their dependencies and run them in isolated environments. Managing these containers efficiently is crucial for ensuring smooth operations and optimal resource utilization. In this comprehensive guide, I will explore different methods to list docker containers in Linux and common errors that can occur while listing containers.

How to List Docker Containers in Linux

To list Docker containers in Linux effectively, use methods like Listing Running Containers for a quick overview, Displaying Container Details for in-depth insights, Filtering Containers by Criteria for focused results, Sorting and Formatting Output for customization, and Listing Stopped Containers for cleanup. 

1. Listing Running Containers

When you need a quick overview of all the running containers on your system, listing running containers is the way to go. It helps you monitor active containers and provides essential information like Container ID, Names, Status, and exposed Ports, ensuring efficient management of your containerized applications. Follow these steps:

1. Open your Terminal window.

2. Enter the following command:

<strong>docker ps</strong>

3. This command will display essential information about each running container, including its Container ID, Names, Status, and exposed Ports.

2. Displaying Container Details

Sometimes, you may need more detailed information about a specific container. By using the docker inspect command with the Container ID or Name, you can access a JSON representation of the container’s configuration and network settings, aiding in troubleshooting and debugging tasks. To inspect a container, do the following:

1. In your command prompt, use the docker inspect command, followed by the Container ID or Name:

<strong>docker inspect container_name_or_id</strong>

2. The output will provide a JSON representation of the container’s configuration, network settings, and more.

3. Filtering Containers by Criteria

Filtering containers can be incredibly useful when you want to focus on specific containers based on certain criteria. It allows you to focus on relevant containers, such as running or stopped ones, and filter by names or other properties, facilitating effective monitoring and management. Here’s how you can do it:

1. Launch your Terminal, use the docker ps command with the --filter flag and the desired filter, such as status=running:

<strong>docker ps --filter status=running</strong>

2. This will display a list of containers that are currently running.

4. Sorting and Formatting Output

Customizing the output of your container listing can make it easier to read and focus on specific details. By using the –format flag with a custom Go template, you can display specific container details like Container ID, Name, and Status, making the output more concise and tailored to your needs. Here’s how you can do it:

1. Enter your command window and type the following command:

<strong>docker ps --format "ID: {{.ID}}\tName: {{.Names}}\tStatus: {{.Status}}"</strong>

2. This will format the output to display only the specified information for each container, making it more readable and concise.

5. Listing Stopped Containers: Cleanup and Maintenance

Over time, you may accumulate stopped containers that are no longer needed, consuming valuable resources. Listing stopped containers can help you identify and clean them up efficiently. Follow these steps:

1. Open your Terminal and enter the following command:

<strong>docker ps -a --filter status=exited</strong>

2. This command will list all containers, including the ones that have exited or stopped. You can now review this list and decide which containers to remove to free up resources.

5 Common Errors When Listing Docker Containers

While listing Docker containers is a routine task for developers, it’s not without its challenges. By being aware of these common errors and their resolutions, you can navigate the challenges of listing Docker containers more effectively and maximize the benefits of containerization in your development workflow. Follow these steps:

• 🚫 No Containers Listed: When you run the docker ps command, you might encounter an empty list with no containers listed. This error usually occurs when no containers are currently running on your system. It’s essential to verify that you have active containers before attempting to list them. Start a container with docker run or check if a running container has exited. Once you have running containers, the docker ps command will display the relevant information.
• 🔐 Access Denied: Receiving an “Access Denied” message when listing containers can be frustrating. This error typically arises due to insufficient permissions to execute Docker commands. To resolve this, ensure that you are part of the Docker user group or have the necessary privileges to interact with the Docker daemon. On Linux, consider adding your user to the docker group using sudo usermod -aG docker $USER. For Windows users, ensure you are using an elevated command prompt or have administrative access.
• 🔌 Unable to Connect to Docker Daemon: If you encounter an error stating “Cannot connect to the Docker daemon,” it indicates a connection problem between the Docker client and the Docker daemon. First, check if the Docker daemon is running using docker info or docker version. If the daemon is not running, start it using sudo systemctl start docker (on Linux) or via the Docker Desktop application (on Windows/Mac). Additionally, verify that you have the necessary network access to communicate with the Docker daemon.
• 🔄 Container Names vs. Container IDs: It’s easy to confuse container names with their unique container IDs when listing containers. Mistaking one for the other can lead to errors or unexpected results. Remember that container names are human-readable, while container IDs are long hexadecimal strings. To list containers using their names, use docker ps -a --filter "name=<container_name>". For listing by container IDs, use docker ps -a --filter "id=<container_id>". Cross-reference the container names and IDs using docker ps -a to avoid confusion.
• ❌ Incorrect Filter Syntax: When using the --filter flag to list containers based on specific criteria, improper syntax can result in errors. Ensure that you use the correct key-value pair syntax for filtering. For instance, to list only running containers, use docker ps --filter "status=running". To filter by a specific label, use docker ps --filter "label=my_label=desired_value". Double-check the filter criteria against the available options to avoid syntax-related errors.

To Sum Up

In this guide, I have provided a comprehensive overview of various methods to list Docker containers in Linux effectively. However, be mindful of common errors such as encountering an empty list, access denied issues, connection problems with the Docker daemon, confusion between container names and IDs, and incorrect filter syntax.

As you continue your Docker journey, consider exploring advanced topics such as Docker networking, Docker volumes to manage data persistence, and Docker Compose to orchestrate multi-container applications. Remember, the world of Docker is vast and ever-evolving, so stay curious, keep learning, and explore the endless possibilities of containerization.

Frequently Asked Questions