Docker - Bind mount
About
bind mount is type of mount. It's one of the three way on how you can persist data from a container. See Docker - Data Persistence
Management
Mount
The file or directory is referenced by its full or relative path on the host machine. The file or directory does not need to exist on the Docker host already.
–mount
docker run -d \
-it \
--name devtest \
--mount type=bind,source="$(pwd)"/target,target=/app \
nginx:latest
-v or –volume
The -v or --volume options when mounting a bind mount, consists of three fields, separated by colon characters :
- the first field is the path to the file or directory on the host machine ( for a volume mount, it would be the volume name)
- the second field is the path where the file or directory is mounted in the container.
- the third field is optional, and is a comma-separated list of options, such as ro, consistent, delegated, cached, z, and Z.
Example:
- bash
docker run -it --rm -v /c/tmp:/pathInContainer/ ubuntu bash
- dos
docker run ^
--name containerName ^
-v %cd%:/var/www/html/ ^
imageName
List
docker inspect containerName
"Mounts": [
{
"Type": "bind",
"Source": "/host_mnt/c/code/bdm",
"Destination": "/ansible/playbooks",
"Mode": "",
"RW": true,
"Propagation": "rprivate"
}
],
This shows that:
- the type of mount,
- the source directory
- the destination directory
- the mode for optional options Example:
- ro for Read only
- z or Z for selinux
- the mount is read-write. Not Read only
- the propagation is set to rprivate. The propagation settings control whether a mount on /tmp/a would also be available on /mnt/a. See propagation
Support
Mount path must be absolute
I got this error using MGINX. Below is a workaround
SOURCE_MOUNT_POINT=$(cygpath -u $(readlink -f ../myRelativePath))
# then mount
docker run \
--mount type=bind,source=/$SOURCE_MOUNT_POINT,target=/var/www/html \
repo/image:tag
Error while creating mount source path: file exists
Error response from daemon: error while creating mount source path '/host_mnt/d/dokuwiki': mkdir /host_mnt/d: file exists
Just restart docker
Mount denied: The source path doesn't exist and is not known to Docker
On Windows 10
docker: Error response from daemon: Mount denied:
The source path "D:/tmp"
doesn't exist and is not known to Docker.
See 'docker run --help'.
Solution: The credentials for the mount have expired, reset them
