This issue was originally reported in podman PR 25792.
When calling runc pause/unpause for an ordinary user, podman do not
provide --systemd-cgroups option, and shouldUseRootlessCgroupManager
returns true. This results in a warning:
$ podman pause sleeper
WARN[0000] runc pause may fail if you don't have the full access to cgroups
sleeper
Actually, it does not make sense to call shouldUseRootlessCgroupManager
at this point, because we already know if we're rootless or not, from
the container state.json (same for systemd).
Also, busctl binary is not available either in this context, so
shouldUseRootlessCgroupManager would not work properly.
Finally, it doesn't really matter if we use systemd or not, because we
use fs/fs2 manager to freeze/unfreeze, and it will return something like
EPERM (or tell that cgroups is not configured, for a true rootless
container).
So, let's only print the warning after pause/unpause failed,
if the error returned looks like a permission error.
Same applies to "runc ps".
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
This was added by commit 5aa82c950 back in the day when we thought
runc is going to be cross-platform. It's very clear now it's Linux-only
package.
While at it, further clarify it in README that we're Linux only.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
This PR decomposes `libcontainer/configs.Config.Rootless bool` into `RootlessEUID bool` and
`RootlessCgroups bool`, so as to make "runc-in-userns" to be more compatible with "rootful" runc.
`RootlessEUID` denotes that runc is being executed as a non-root user (euid != 0) in
the current user namespace. `RootlessEUID` is almost identical to the former `Rootless`
except cgroups stuff.
`RootlessCgroups` denotes that runc is unlikely to have the full access to cgroups.
`RootlessCgroups` is set to false if runc is executed as the root (euid == 0) in the initial namespace.
Otherwise `RootlessCgroups` is set to true.
(Hint: if `RootlessEUID` is true, `RootlessCgroups` becomes true as well)
When runc is executed as the root (euid == 0) in an user namespace (e.g. by Docker-in-LXD, Podman, Usernetes),
`RootlessEUID` is set to false but `RootlessCgroups` is set to true.
So, "runc-in-userns" behaves almost same as "rootful" runc except that cgroups errors are ignored.
This PR does not have any impact on CLI flags and `state.json`.
Note about CLI:
* Now `runc --rootless=(auto|true|false)` CLI flag is only used for setting `RootlessCgroups`.
* Now `runc spec --rootless` is only required when `RootlessEUID` is set to true.
For runc-in-userns, `runc spec` without `--rootless` should work, when sufficient numbers of
UID/GID are mapped.
Note about `$XDG_RUNTIME_DIR` (e.g. `/run/user/1000`):
* `$XDG_RUNTIME_DIR` is ignored if runc is being executed as the root (euid == 0) in the initial namespace, for backward compatibility.
(`/run/runc` is used)
* If runc is executed as the root (euid == 0) in an user namespace, `$XDG_RUNTIME_DIR` is honored if `$USER != "" && $USER != "root"`.
This allows unprivileged users to allow execute runc as the root in userns, without mounting writable `/run/runc`.
Note about `state.json`:
* `rootless` is set to true when `RootlessEUID == true && RootlessCgroups == true`.
Signed-off-by: Akihiro Suda <suda.akihiro@lab.ntt.co.jp>
As per the discussions in #1156 , we think it's a bad
idea to allow multi container operations in runc. So
revert it.
Signed-off-by: Qiang Huang <h.huangqiang@huawei.com>
