How to Copy files from Docker container to the Host machine?

Docker is a popular platform that allows developers to easily create, deploy, and manage applications within containers. One of the benefits of using Docker is that it provides a way to isolate your applications and their dependencies, making them more portable and easier to manage.

However, there may be times when you need to copy files from your Docker container to the host machine. This could be useful for debugging purposes or to share files with other team members. In this blog post, we will explore how to copy files from a Docker container to the host machine.

Step 1: Identify the container ID or name

Before you can copy files from a Docker container to the host machine, you need to identify the container ID or name. You can do this by running the following command:

docker ps

This command will display a list of all running containers on your system. Look for the container that you want to copy files from and take note of its ID or name.

Step 2: Copy files from container to host

Once you have identified the container ID or name, you can use the following command to copy files from the container to the host:

docker cp <containerId>:/path/to/file /path/on/host

In this command, replace with the ID or name of the container you want to copy files from. Replace /path/to/file with the path to the file you want to copy from the container, and replace /path/on/host with the path on the host machine where you want to save the file.

For example, if you wanted to copy a file named example.txt from a container with ID abc123 to a folder named data on the host machine, you would run the following command:

docker cp abc123:/app/example.txt /home/user/data

This command would copy the example.txt file from the /app directory in the container to the /home/user/data directory on the host machine.

Step 3: Verify the copied file

After running the docker cp command, you should verify that the file was copied correctly to the host machine. You can do this by navigating to the directory where you copied the file and checking that it exists and contains the expected content.

cd /path/on/host
ls

This command will display a list of all files and directories in the /path/on/host directory. Look for the file you just copied and verify that its content matches the original file in the container.

Bonus Tip: Copy multiple files or directories

If you need to copy multiple files or directories from a Docker container to the host machine, you can use the docker cp command with the -r flag to recursively copy directories.

docker cp -r <containerId>:/path/to/directory /path/on/host

In this command, replace with the ID or name of the container you want to copy files from. Replace /path/to/directory with the path to the directory you want to copy from the container, and replace /path/on/host with the path on the host machine where you want to save the files.

For example, if you wanted to copy a directory named data from a container with ID abc123 to a folder named backup on the host machine, you would run the following command:

docker cp -r abc123:/app/data /home/user/backup

This command would copy the entire data directory and its contents from the /app directory in the container to the /home/user/backup directory on the host machine.

Conclusion

Copying files from a Docker container to the host machine is a useful technique.