Creating a bind mount into a docker container (docker)

By default, data in a container does not persist when a running container is stopped. Also, it is difficult to get data out of a running container if it is needed by another process.

One way to get around this is to store files on the host machine using a bind mount. (The other way is by using volumes, which are similar but have some important differences not discussed here.)

Bind mounts map an existing directory on the host machine to a directory in the container. Bind mounts are particularly useful when developing within a container. Any changes to the source code in a bind mounted directory on the host machine are immediately available within the container.

Bind mounts can be created either with the -v/--volume flag or with the --mount flag. It is recommended to use the --mount syntax.

docker run -d \
  -it \
  --name devtest \
  --mount type=bind,source="$(pwd)"/target,target=/app \
  nginx:latest

From the Docker docs

–mount: Consists of multiple key-value pairs, separated by commas and each consisting of a = tuple. The --mount syntax is more verbose than -v or --volume, but the order of the keys is not significant, and the value of the flag is easier to understand.

• The type of the mount, which can be bind, volume, or tmpfs. This topic discusses bind mounts, so the type is always bind.
• The source of the mount. For bind mounts, this is the path to the file or directory on the Docker daemon host. May be specified as source or src.
• The destination takes as its value the path where the file or directory is mounted in the container. May be specified as destination, dst, or target.
• The readonly option, if present, causes the bind mount to be mounted into the container as read-only.
• The bind-propagation option, if present, changes the bind propagation. May be one of rprivate, private, rshared, shared, rslave, slave.
• The --mount flag does not support z or Z options for modifying selinux labels.

Docker Docs storage overview