How to copy files from Docker container to host?

To copy files from a Docker container to your host machine, use the following methods:

1. Using docker cp (Simplest Method)

Copy files or directories directly from a container to the host using the container’s ID or name.

Syntax:

docker cp <container_id>:<container_source_path> <host_destination_path>

Example:

# Copy a single file
docker cp my_container:/app/data.txt ./downloads/

# Copy an entire directory
docker cp my_container:/var/log/nginx ./nginx_logs

Notes:

• Works for stopped or running containers.
• Use docker ps -a to list all containers and their IDs/names.

2. Mount a Volume (Pre-Configured Access)

Mount a host directory as a volume when starting the container to automatically share files.

Example:

# Start a container with a mounted host directory
docker run -v /host/path:/container/path my_image

# Files written to `/container/path` in the container will appear in `/host/path` on the host

3. Redirect Output with docker run

For small files, redirect the output of a command to a host file.

Example:

# Save the output of a file to the host
docker run my_container cat /app/config.json > ./config.json

4. Advanced: Use tar with docker exec

Stream files from the container to the host using tar (useful for large directories).

Example:

# Archive and extract files from container to host
docker exec my_container tar -cf - /path/to/files | tar -xf - -C ./host_dir

Key Tips

• Permissions: Files copied to the host inherit permissions from the container (use sudo if needed).
• Copy from Host to Container: Reverse the arguments:

  docker cp ./host_file.txt my_container:/container/path/

• Wildcards: Not directly supported in docker cp—use shell tricks like:

  docker exec my_container sh -c 'cp /app/*.log /tmp' && docker cp my_container:/tmp/ ./logs

Example Workflow

# List containers
docker ps -a

# Copy a config file from a stopped container
docker cp 5a2d3b1e:/etc/nginx/nginx.conf ./nginx.conf

# Verify the file
ls -l ./nginx.conf

Use docker cp for quick one-off transfers, and volumes for persistent shared directories.