How to mount a single file with `docker run`?

Question

In docker-compose, this works fine:

  nginx:
    image: nginx:latest
    network_mode: host
    volumes:
      - web_server/local-nginx.conf:/etc/nginx/nginx.conf
    ports:
      - 8080:8080

However, if I try to do the same thing using docker run directly:

$ docker run --network host -p 8080:8080 \
  -v "web_server/local-nginx.conf:/etc/nginx/nginx.conf" \
  nginx:latest

I get errors:

docker: Error response from daemon: create web_server/local-nginx.conf: "web_server/local-nginx.conf"
includes invalid characters for a local volume name, only "[a-zA-Z0-9][a-zA-Z0-9_.-]" are allowed. 
If you intended to pass a host directory, use absolute path.

I also tried using --mount , with the same results:

$ docker run -p 8080:8080 --network host \
  --mount src="web_server/local-nginx.conf",dst="/etc/nginx/nginx.conf" \
  nginx:latest

Answer 1

The left-hand side of the docker run -v option must be a volume name or an absolute path. Docker Compose understands relative paths in volumes: , but plain Docker doesn't.

You need to include the current directory name in the option. Using the $PWD environment variable for this is common:

docker run ... \
  -v "$PWD/web_server/local-nginx.conf:/etc/nginx/nginx.conf" \
  ...