How to Use Bind Mount in Docker: Syntax and Examples

Use a bind mount in Docker by adding the -v or --mount flag with the host path and container path separated by a colon, like -v /host/path:/container/path. This lets your container access files directly from your host machine.

Syntax

The basic syntax for a bind mount in Docker uses the -v or --mount option to link a directory or file from your host to the container.

• -v /host/path:/container/path: Mounts the host directory or file at /host/path into the container at /container/path.
• --mount type=bind,source=/host/path,target=/container/path: A more explicit syntax introduced in Docker 17.06+ that clearly defines the mount type and paths.

Both methods let the container read and write files directly on your host system.

bash

docker run -v /host/path:/container/path image_name

docker run --mount type=bind,source=/host/path,target=/container/path image_name

Example

This example shows how to run an nginx container that serves a static website from a folder on your host machine.

We mount the host folder /home/user/website to the container's /usr/share/nginx/html directory where nginx serves files.

bash

docker run -d -p 8080:80 -v /home/user/website:/usr/share/nginx/html:ro nginx

Output

a1b2c3d4e5f6g7h8i9j0

# Container runs in background, serving files from host folder on http://localhost:8080

Common Pitfalls

• Wrong host path: The host path must exist; otherwise, Docker creates an empty directory which may cause confusion.
• Permission issues: The container user must have permission to read/write the host files.
• Read-only mounts: Add :ro at the end of the volume to prevent container from modifying host files.
• Using relative paths: Always use absolute paths for host directories.

bash

docker run -v ./website:/usr/share/nginx/html nginx
# This creates an empty directory inside the container if ./website does not exist or is relative.

docker run -v /home/user/website:/usr/share/nginx/html:ro nginx
# Mounts the folder read-only to protect host files.

Quick Reference

Option	Description	Example
-v /host/path:/container/path	Bind mount host directory to container	docker run -v /data:/app/data myimage
--mount type=bind,source=/host/path,target=/container/path	Explicit bind mount syntax	docker run --mount type=bind,source=/data,target=/app/data myimage
:ro	Make mount read-only	docker run -v /data:/app/data:ro myimage
Absolute paths	Host paths must be absolute	Use /home/user/data, not ./data

Key Takeaways

Use -v or --mount with absolute host paths to create bind mounts in Docker.

Bind mounts let containers access and modify files directly on your host machine.

Add :ro to make mounts read-only and protect host files.

Ensure host paths exist and permissions allow container access.

Prefer --mount syntax for clarity and newer Docker versions.