To copy files from the host machine to a Docker container, you can use the “docker cp” command. This command allows you to copy files and directories between the host and the container.
Here are the step-by-step instructions:
Step 1: Find the container ID or name
First, you need to identify the Docker container to which you want to copy the files. You can find the container ID or name by using the “docker ps” command. This command lists all the running containers.
docker ps
The output will display the container ID or name, along with other details such as the image, command, and status.
Related Article: Installing Docker on Ubuntu in No Time: a Step-by-Step Guide
Step 2: Copy files from host to container
Once you have identified the container, you can use the “docker cp” command to copy files from the host machine to the container. The syntax for the command is as follows:
docker cp :
Replace with the path to the file or directory on your host machine that you want to copy. Replace with the ID or name of the Docker container. Finally, replace with the path inside the container where you want to copy the files.
For example, let’s say you want to copy a file named “example.txt” from the “/tmp” directory on your host machine to the “/app” directory inside the container with the container ID “abc123”:
docker cp /tmp/example.txt abc123:/app
This command will copy the “example.txt” file from your host machine to the “/app” directory inside the container.
Step 3: Verify the file copy
To verify that the file has been copied successfully, you can use the “docker exec” command to run a command inside the container and check the contents of the destination directory. For example, you can run the following command to list the files in the “/app” directory inside the container:
docker exec ls
Replace with the ID or name of the Docker container, and with the path inside the container where you copied the files.
For example:
docker exec abc123 ls /app
This command will list the files in the “/app” directory inside the container.
Alternative method: Mount a volume
Another way to copy files from the host to a Docker container is by using a volume. Volumes allow you to share data between the host machine and the container. By mounting a volume, any changes made to the files on the host machine will be immediately reflected in the container, and vice versa.
To mount a volume, you can use the “-v” or “–volume” option when running the Docker container. The syntax is as follows:
docker run -v :
Replace with the path to the file or directory on your host machine that you want to share with the container. Replace with the path inside the container where you want to mount the volume. Finally, replace with the name of the Docker image you want to run.
For example, let’s say you want to mount the “/tmp” directory on your host machine to the “/app” directory inside the container:
docker run -v /tmp:/app
This command will run the Docker container and mount the “/tmp” directory on your host machine to the “/app” directory inside the container.
Once the volume is mounted, any changes made to the files in the “/tmp” directory on your host machine will be immediately available inside the “/app” directory inside the container.
Related Article: How to Install and Use Docker
Best practices
Here are some best practices to keep in mind when copying files from the host to a Docker container:
1. Use specific paths: Specify the full path to the files or directories you want to copy from the host machine to the container. This helps avoid any confusion or ambiguity.
2. Check file permissions: Ensure that the permissions of the files or directories you are copying are set correctly. If you encounter any permission issues inside the container, you may need to adjust the permissions on the host machine.
3. Use volumes for frequent changes: If you anticipate frequent changes to the files, consider using volumes instead of manually copying the files. Volumes provide a more seamless and efficient way to share data between the host and the container.
4. Clean up after copying: Once you have copied the files to the container, make sure to remove any temporary files or unnecessary data from the host machine. This helps keep your environment clean and reduces disk usage.