Early deprecation warning for 'docker commit --run'

Warn users of the planned deprecation of 'docker commit --run', and hide
it from the docs and usage message. The option continues to work.

Note that an alternative to 'commit --run' is being implemented but is
not yet available. We are printing the warning anyway because on
the basis that it never hurts to give more advance warning.

The 'commit --run' flag is a leftover from the very early days of Docker,
and has several problems:

1) It is very user unfriendly. You have to pass a literal json dict
which is poorly documented and changes regularly (see PortSpecs vs
ExposedPorts). The merge behavior is not clear and also changes
regularly. it's not possible to unset a value.

2) It overlaps with the Dockerfile syntax. There are 2 ways to set
a default command, expose a port or change an env variable. Some
things can be done in a Dockerfile but not in --run. Some things
can be done in --run but not in a Dockerfile. It would be better
to push a single syntax, allow using it both in a file and via
the command line, and make improvements in a single place.

3) It exposes data structures which should not be publicly exposed.
There are several planned improvements to Docker which require moving
around the content and schema of the various Config, Image and Container
structures. The less of those we expose in public interfaces, the easier
it is to move things around without a reverse compatibility nightmare.

Docker-DCO-1.1-Signed-off-by: Solomon Hykes <solomon@docker.com> (github: shykes)
This commit is contained in:
Solomon Hykes 2014-04-08 09:49:48 -07:00 committed by Tibor Vass
parent 5717858626
commit 8777b52219
2 changed files with 5 additions and 99 deletions

View File

@ -188,9 +188,7 @@ omit the executable, in which case you must specify an ENTRYPOINT as
well.
When used in the shell or exec formats, the ``CMD`` instruction sets
the command to be executed when running the image. This is
functionally equivalent to running ``docker commit --run '{"Cmd":
<command>}'`` outside the builder.
the command to be executed when running the image.
If you use the *shell* form of the CMD, then the ``<command>`` will
execute in ``/bin/sh -c``:
@ -230,10 +228,10 @@ override the default specified in CMD.
``EXPOSE <port> [<port>...]``
The ``EXPOSE`` instruction exposes ports for use within links. This is
functionally equivalent to running ``docker commit --run '{"PortSpecs":
["<port>", "<port2>"]}'`` outside the builder. Refer to
:ref:`port_redirection` for detailed information.
The ``EXPOSE`` instructions informs Docker that the container will listen
on the specified network ports at runtime. Docker uses this information
to interconnect containers using links (see :ref:`links <working_with_links_names>`),
and to setup port redirection on the host system (see :ref:`port_redirection`).
.. _dockerfile_env:

View File

@ -316,8 +316,6 @@ by using the ``git://`` schema.
-m, --message="": Commit message
-a, --author="": Author (eg. "John Hannibal Smith <hannibal@a-team.com>"
--run="": Configuration changes to be applied when the image is launched with `docker run`.
(ex: --run='{"Cmd": ["cat", "/world"], "PortSpecs": ["22"]}')
.. _cli_commit_examples:
@ -336,96 +334,6 @@ Commit an existing container
REPOSITORY TAG ID CREATED VIRTUAL SIZE
SvenDowideit/testimage version3 f5283438590d 16 seconds ago 335.7 MB
Change the command that a container runs
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Sometimes you have an application container running just a service and you need
to make a quick change and then change it back.
In this example, we run a container with ``ls`` and then change the image to
run ``ls /etc``.
.. code-block:: bash
$ docker run -t --name test ubuntu ls
bin boot dev etc home lib lib64 media mnt opt proc root run sbin selinux srv sys tmp usr var
$ docker commit --run='{"Cmd": ["ls","/etc"]}' test test2
933d16de9e70005304c1717b5c6f2f39d6fd50752834c6f34a155c70790011eb
$ docker run -t test2
adduser.conf gshadow login.defs rc0.d
alternatives gshadow- logrotate.d rc1.d
apt host.conf lsb-base rc2.d
...
Merged configs example
......................
Say you have a Dockerfile like so:
.. code-block:: bash
ENV MYVAR foobar
RUN apt-get install openssh
EXPOSE 22
CMD ["/usr/sbin/sshd -D"]
...
If you run that, make some changes, and then commit, Docker will merge the environment variable and exposed port configuration settings with any that you specify in the --run= option. This is a change from Docker 0.8.0 and prior where no attempt was made to preserve any existing configuration on commit.
.. code-block:: bash
$ docker build -t me/foo .
$ docker run -t -i me/foo /bin/bash
foo-container$ [make changes in the container]
foo-container$ exit
$ docker commit --run='{"Cmd": ["ls"]}' [container-id] me/bar
...
The me/bar image will now have port 22 exposed, MYVAR env var set to 'foobar', and its default command will be ["ls"].
Note that this is currently a shallow merge. So, for example, if you had specified a new port spec in the --run= config above, that would have clobbered the 'EXPOSE 22' setting from the parent container.
Full --run example
..................
The ``--run`` JSON hash changes the ``Config`` section when running ``docker inspect CONTAINERID``
or ``config`` when running ``docker inspect IMAGEID``. Existing configuration key-values that are
not overridden in the JSON hash will be merged in.
(Multiline is okay within a single quote ``'``)
.. code-block:: bash
$ sudo docker commit --run='
{
"Entrypoint" : null,
"Privileged" : false,
"User" : "",
"VolumesFrom" : "",
"Cmd" : ["cat", "-e", "/etc/resolv.conf"],
"Dns" : ["8.8.8.8", "8.8.4.4"],
"DnsSearch" : ["example.com"],
"MemorySwap" : 0,
"AttachStdin" : false,
"AttachStderr" : false,
"CpuShares" : 0,
"OpenStdin" : false,
"Volumes" : null,
"Hostname" : "122612f45831",
"PortSpecs" : ["22", "80", "443"],
"Image" : "b750fe79269d2ec9a3c593ef05b4332b1d1a02a62b4accb2c21d589ff2f5f2dc",
"Tty" : false,
"Env" : [
"HOME=/",
"PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"
],
"StdinOnce" : false,
"Domainname" : "",
"WorkingDir" : "/",
"NetworkDisabled" : false,
"Memory" : 0,
"AttachStdout" : false
}' $CONTAINER_ID
.. _cli_cp: