This adds both a daemon-wide flag and a container creation property:
- Set the `CgroupnsMode: "host|private"` HostConfig property at
container creation time to control what cgroup namespace the container
is created in
- Set the `--default-cgroupns-mode=host|private` daemon flag to control
what cgroup namespace containers are created in by default
- Set the default if the daemon flag is unset to "host", for backward
compatibility
- Default to CgroupnsMode: "host" for client versions < 1.40
Signed-off-by: Rob Gulewich <rgulewich@netflix.com>
The `--rootless` flag had a couple of issues:
* #38702: euid=0, $USER="root" but no access to cgroup ("rootful" Docker in rootless Docker)
* #39009: euid=0 but $USER="docker" (rootful boot2docker)
To fix#38702, XDG dirs are ignored as in rootful Docker, unless the
dockerd is directly running under RootlessKit namespaces.
RootlessKit detection is implemented by checking whether `$ROOTLESSKIT_STATE_DIR` is set.
To fix#39009, the non-robust `$USER` check is now completely removed.
The entire logic can be illustrated as follows:
```
withRootlessKit := getenv("ROOTLESSKIT_STATE_DIR")
rootlessMode := withRootlessKit || cliFlag("--rootless")
honorXDG := withRootlessKit
useRootlessKitDockerProxy := withRootlessKit
removeCgroupSpec := rootlessMode
adjustOOMScoreAdj := rootlessMode
```
Close#39024Fix#38702#39009
Signed-off-by: Akihiro Suda <akihiro.suda.cz@hco.ntt.co.jp>
Please refer to `docs/rootless.md`.
TLDR:
* Make sure `/etc/subuid` and `/etc/subgid` contain the entry for you
* `dockerd-rootless.sh --experimental`
* `docker -H unix://$XDG_RUNTIME_DIR/docker.sock run ...`
Signed-off-by: Akihiro Suda <suda.akihiro@lab.ntt.co.jp>
The `--enable-api-cors` flag was deprecated in f3dd2db4ff,
and marked for removal in docker 17.09 through 85f92ef359.
This patch removes the deprecated flag.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
Since the commit d88fe447df ("Add support for sharing /dev/shm/ and
/dev/mqueue between containers") container's /dev/shm is mounted on the
host first, then bind-mounted inside the container. This is done that
way in order to be able to share this container's IPC namespace
(and the /dev/shm mount point) with another container.
Unfortunately, this functionality breaks container checkpoint/restore
(even if IPC is not shared). Since /dev/shm is an external mount, its
contents is not saved by `criu checkpoint`, and so upon restore any
application that tries to access data under /dev/shm is severily
disappointed (which usually results in a fatal crash).
This commit solves the issue by introducing new IPC modes for containers
(in addition to 'host' and 'container:ID'). The new modes are:
- 'shareable': enables sharing this container's IPC with others
(this used to be the implicit default);
- 'private': disables sharing this container's IPC.
In 'private' mode, container's /dev/shm is truly mounted inside the
container, without any bind-mounting from the host, which solves the
issue.
While at it, let's also implement 'none' mode. The motivation, as
eloquently put by Justin Cormack, is:
> I wondered a while back about having a none shm mode, as currently it is
> not possible to have a totally unwriteable container as there is always
> a /dev/shm writeable mount. It is a bit of a niche case (and clearly
> should never be allowed to be daemon default) but it would be trivial to
> add now so maybe we should...
...so here's yet yet another mode:
- 'none': no /dev/shm mount inside the container (though it still
has its own private IPC namespace).
Now, to ultimately solve the abovementioned checkpoint/restore issue, we'd
need to make 'private' the default mode, but unfortunately it breaks the
backward compatibility. So, let's make the default container IPC mode
per-daemon configurable (with the built-in default set to 'shareable'
for now). The default can be changed either via a daemon CLI option
(--default-shm-mode) or a daemon.json configuration file parameter
of the same name.
Note one can only set either 'shareable' or 'private' IPC modes as a
daemon default (i.e. in this context 'host', 'container', or 'none'
do not make much sense).
Some other changes this patch introduces are:
1. A mount for /dev/shm is added to default OCI Linux spec.
2. IpcMode.Valid() is simplified to remove duplicated code that parsed
'container:ID' form. Note the old version used to check that ID does
not contain a semicolon -- this is no longer the case (tests are
modified accordingly). The motivation is we should either do a
proper check for container ID validity, or don't check it at all
(since it is checked in other places anyway). I chose the latter.
3. IpcMode.Container() is modified to not return container ID if the
mode value does not start with "container:", unifying the check to
be the same as in IpcMode.IsContainer().
3. IPC mode unit tests (runconfig/hostconfig_test.go) are modified
to add checks for newly added values.
[v2: addressed review at https://github.com/moby/moby/pull/34087#pullrequestreview-51345997]
[v3: addressed review at https://github.com/moby/moby/pull/34087#pullrequestreview-53902833]
[v4: addressed the case of upgrading from older daemon, in this case
container.HostConfig.IpcMode is unset and this is valid]
[v5: document old and new IpcMode values in api/swagger.yaml]
[v6: add the 'none' mode, changelog entry to docs/api/version-history.md]
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
The daemon config for defaulting to no-new-privileges for containers was
added in d7fda019bb, but somehow we
managed to omit the flag itself, but also documented the flag.
This just adds the actual flag.
Signed-off-by: Brian Goff <cpuguy83@gmail.com>
This also moves some cli specific in `cmd/dockerd` as it does not
really belong to the `daemon/config` package.
Signed-off-by: Vincent Demeester <vincent@sbr.pm>
Rob Gulewich