Working with Docker containers often involves manipulating files—whether it’s exporting logs, downloading generated assets, or retrieving data for debugging. Fortunately, Docker provides a simple way to copy files from inside a container to your local host system.
In this guide, you’ll learn how to copy files or folders from a Docker container to the host, with clear examples and best practices.
✅ Method 1: Using docker cp Command
The easiest and most common way to copy files from a running (or even stopped) container to the host is with the docker cp command.
Syntax:
docker cp <container-id>:<container-path> <host-path>
📁 Example: Copy a File from Container to Host
Suppose you have a container named my_container, and you want to copy a file located at /app/output.txt to your local machine:
docker cp my_container:/app/output.txt ./output.txt
This command will copy the file to your current working directory on the host.
📁 Example: Copy a Folder
To copy an entire directory from the container to the host:
docker cp my_container:/var/logs ./logs
This copies the /var/logs folder inside the container to a folder named logs on your host.
🔍 How to Find the Container Name or ID
To list your running containers:
docker ps
To list all containers (including stopped ones):
docker ps -a
Use the value from the CONTAINER ID or NAMES column in the docker cp command.
✅ Method 2: Using docker exec + cat (for Quick File Reads)
If you just want to view or stream a file’s content rather than saving it, you can use docker exec and cat:
docker exec my_container cat /app/output.txt
Or to save it:
docker exec my_container cat /app/output.txt > output.txt
This method is handy for small text files or logs.
✅ Method 3: Archive & Transfer (Advanced)
To compress multiple files or folders inside the container and transfer them as a single archive:
docker exec my_container tar czf - /app/data | tar xzf - -C .
This command:
- Creates a
.tar.gzarchive inside the container - Streams it to the host
- Extracts it into the current host directory
Great for moving large or nested directory structures.
🧠 Best Practices
- Ensure the container path exists before copying; otherwise, Docker will throw an error.
- The
docker cpcommand works even for stopped containers. - Be careful when copying files into host system directories—avoid overwriting important files.
- For frequent file transfer, consider using volumes instead of copy commands.
✅ Summary
| Task | Command Example |
|---|---|
| Copy a file from container to host | docker cp my_container:/app/file.txt ./file.txt |
| Copy a folder | docker cp my_container:/app/folder ./folder |
| Read a file without saving | docker exec my_container cat /path/to/file |
| Copy multiple files as archive | `docker exec my_container tar czf – /path |
By mastering Docker’s file copy commands, you’ll make your workflows more efficient—especially when extracting logs, backups, and configuration files.