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Docker notes
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/var/lib/docker on macOS
========================

In macOS, docker commands (e.g., `docker volume inspect`) return 
references to `/var/lib/docker`, however this directory does not exist
on the macOS host.

A way to check on it (ref. [dockernotes-01]_):

.. code-block:: fish

  > docker run -it --privileged --pid=host debian nsenter -t 1 -m -u -n -i sh 


References
----------

.. [dockernotes-01] `Where is /var/lib/docker on Mac/OS X (Stack Overflow)
   <https://stackoverflow.com/questions/38532483/where-is-var-lib-docker-on-mac-os-x>`_
   (Retrieved 2021-08-04)


Determine the container using a docker volume
=============================================

Ref. [dockernotes-02]_ :

.. code-block:: fish

  docker ps -a --filter volume=VOLUME_NAME_OR_MOUNT_POINT


.. code-block:: fish

  docker volume ls --filter name=container_name


References
----------

.. [dockernotes-02] `How to determine what containers use the docker volume? (Stack Overflow)
   <https://stackoverflow.com/questions/42857575/how-to-determine-what-containers-use-the-docker-volume/42858081>`_
   (retrieved 2021-08-04)


Find the owner of a process running on a container without ps
=============================================================

Ref. [dockernotes-03]_ :

- Simplest way seem to be using `docker top` command:

  .. code-block:: fish

    > docker ps
    CONTAINER ID   IMAGE               COMMAND         CREATED        STATUS       PORTS                                       NAMES
    dfc7f2476fc9   contnotebook_docs   "/start-docs"   23 hours ago   Up 6 hours   0.0.0.0:7000->7000/tcp, :::7000->7000/tcp   contnotebook_docs

    > docker top dfc7
    UID                 PID                 PPID                C                   STIME               TTY                 TIME                CMD
    root                18872               18844               0                   Aug04               ?                   00:00:00            /bin/bash /start-docs
    root                18982               18872               0                   Aug04               ?                   00:00:00            make livehtml
    root                18983               18982               1                   Aug04               ?                   00:03:15            /usr/local/bin/python /usr/local/bin/sphinx-autobuild -b html --host 0.0.0.0 --port 7000 -c . . _build/html

- Another way: find the information relative to a process in 
  `/proc/PROCESS_ID/status`


References
----------

.. [dockernotes-03] `how to find owner of a process without ps (Stack Overflow)
   <https://stackoverflow.com/questions/59582151/how-to-find-owner-of-a-process-without-ps>`_
   (retrieved 2021-08-04)