This was initially added by commits 41d9d26513 and 4a8f0b4db4,
apparently to implement docker run --cgroup container:ID, which was
never merged. Therefore, this code is not and was never used.
It needs to be removed mainly because having it makes it much harder to
understand how cgroup manager works (because with this in place we have
not one or two but three sets of cgroup paths to think about).
Note if the paths are known and there is a need to add a PID to existing
cgroup, cgroup manager is not needed at all -- something like
cgroups.WriteCgroupProc or cgroups.EnterPid is sufficient (and the
latter is what runc exec uses in (*setnsProcess).start).
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
gofumpt (mvdan.cc/gofumpt) is a fork of gofmt with stricter rules.
Brought to you by
git ls-files \*.go | grep -v ^vendor/ | xargs gofumpt -s -w
Looking at the diff, all these changes make sense.
Also, replace gofmt with gofumpt in golangci.yml.
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Function defaultPath always parses /proc/self/cgroup, but
the resulting value is not always used.
Avoid unnecessary reading/parsing by moving the code
to just before its use.
Modify the test case accordingly.
[v2: test: use UnifiedMountpoint, skip test if not on v2]
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
When the cgroupv2 fs driver is used without setting cgroupsPath,
it picks up a path from /proc/self/cgroup. On a host with systemd,
such a path can look like (examples from my machines):
- /user.slice/user-1000.slice/session-4.scope
- /user.slice/user-1000.slice/user@1000.service/gnome-launched-xfce4-terminal.desktop-4260.scope
- /user.slice/user-1000.slice/user@1000.service/gnome-terminal-server.service
This cgroup already contains processes in it, which prevents to enable
controllers for a sub-cgroup (writing to cgroup.subtree_control fails
with EBUSY or EOPNOTSUPP).
Obviously, a parent cgroup (which does not contain tasks) should be used.
Fixes opencontainers/runc/issues/2298
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
The Err() method should be called after the Scan() loop, not inside it.
Found by
git grep -A3 -F '.Scan()' | grep Err
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
split fs2 package from fs, as mixing up fs and fs2 is very likely to result in
unmaintainable code.
Inspired by containerd/cgroups#109
Fix#2157
Signed-off-by: Akihiro Suda <akihiro.suda.cz@hco.ntt.co.jp>
Kir Kolyshkin