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Docker

https://docs.docker.com/storage/volumes/

Copying files from/to images

docker cp dockerimage:/bla ./bla
docker cp ./bla dockerimage:/bla

Change mount points of existing docker containers;

e.g. mount /home/<user-name> folder of host to the /mnt folder of the existing (not running) container.

stop docker container or whole docker engine
```
systemctl stop docker.service
```

Open configuration file corresponding to the stopped container, which can be found at /var/lib/docker/containers/99d…1fb/config.v2.json (may be config.json for older versions of docker). For pretty print use

vi <(jq . /var/lib/docker/containers/<container-ID>/config.v2.json)
Save updates to a file: :w config.v2.json
Exit vim: :q!
Update existing file: jq -c . config.v2.json > /var/lib/docker/containers/<container-ID>/config.v2.json

Find MountPoints section: “MountPoints”:{}.

Replace the contents with something like this (you can copy proper contents from another container with proper settings):

"MountPoints":{"/mnt":{"Source":"/home/<user-name>","Destination":"/mnt","RW":true,"Name":"","Driver":"","Type":"bind","Propagation":"rprivate","Spec":{"Type":"bind","Source":"/home/<user-name>","Target":"/mnt"},"SkipMountpointCreation":false}}

or the same (formatted):

  "MountPoints": {
    "/mnt": {
      "Source": "/home/<user-name>",
      "Destination": "/mnt",
      "RW": true,
      "Name": "",
      "Driver": "",
      "Type": "bind",
      "Propagation": "rprivate",
      "Spec": {
        "Type": "bind",
        "Source": "/home/<user-name>",
        "Target": "/mnt"
      },
      "SkipMountpointCreation": false
    }
  }

Start or restart the docker service:

systemctl start docker.service
service docker restart

Start the container if necessary:
```
docker start <container-name/ID>
```