From 4d800a5f45abba9c17d4b3a4c04af563c9a2f4da Mon Sep 17 00:00:00 2001 From: Matthew Heon Date: Thu, 8 Oct 2020 15:25:06 -0400 Subject: Store cgroup manager on a per-container basis When we create a container, we assign a cgroup parent based on the current cgroup manager in use. This parent is only usable with the cgroup manager the container is created with, so if the default cgroup manager is later changed or overridden, the container will not be able to start. To solve this, store the cgroup manager that created the container in container configuration, so we can guarantee a container with a systemd cgroup parent will always be started with systemd cgroups. Unfortunately, this is very difficult to test in CI, due to the fact that we hard-code cgroup manager on all invocations of Podman in CI. Fixes #7830 Signed-off-by: Matthew Heon --- libpod/oci_conmon_linux.go | 12 ++++-------- 1 file changed, 4 insertions(+), 8 deletions(-) (limited to 'libpod/oci_conmon_linux.go') diff --git a/libpod/oci_conmon_linux.go b/libpod/oci_conmon_linux.go index 7fb374e0d..94630e57b 100644 --- a/libpod/oci_conmon_linux.go +++ b/libpod/oci_conmon_linux.go @@ -57,7 +57,6 @@ type ConmonOCIRuntime struct { path string conmonPath string conmonEnv []string - cgroupManager string tmpDir string exitsDir string socketsDir string @@ -102,7 +101,6 @@ func newConmonOCIRuntime(name string, paths []string, conmonPath string, runtime runtime.runtimeFlags = runtimeFlags runtime.conmonEnv = runtimeCfg.Engine.ConmonEnvVars - runtime.cgroupManager = runtimeCfg.Engine.CgroupManager runtime.tmpDir = runtimeCfg.Engine.TmpDir runtime.logSizeMax = runtimeCfg.Containers.LogSizeMax runtime.noPivot = runtimeCfg.Engine.NoPivotRoot @@ -149,10 +147,6 @@ func newConmonOCIRuntime(name string, paths []string, conmonPath string, runtime runtime.exitsDir = filepath.Join(runtime.tmpDir, "exits") runtime.socketsDir = filepath.Join(runtime.tmpDir, "socket") - if runtime.cgroupManager != config.CgroupfsCgroupsManager && runtime.cgroupManager != config.SystemdCgroupsManager { - return nil, errors.Wrapf(define.ErrInvalidArg, "invalid cgroup manager specified: %s", runtime.cgroupManager) - } - // Create the exit files and attach sockets directories if err := os.MkdirAll(runtime.exitsDir, 0750); err != nil { // The directory is allowed to exist @@ -1325,7 +1319,7 @@ func (r *ConmonOCIRuntime) sharedConmonArgs(ctr *Container, cuuid, bundlePath, p args = append(args, rFlags...) } - if r.cgroupManager == config.SystemdCgroupsManager && !ctr.config.NoCgroups && ctr.config.CgroupsMode != cgroupSplit { + if ctr.CgroupManager() == config.SystemdCgroupsManager && !ctr.config.NoCgroups && ctr.config.CgroupsMode != cgroupSplit { args = append(args, "-s") } @@ -1442,8 +1436,10 @@ func (r *ConmonOCIRuntime) moveConmonToCgroupAndSignal(ctr *Container, cmd *exec } if mustCreateCgroup { + // TODO: This should be a switch - we are not guaranteed that + // there are only 2 valid cgroup managers cgroupParent := ctr.CgroupParent() - if r.cgroupManager == config.SystemdCgroupsManager { + if ctr.CgroupManager() == config.SystemdCgroupsManager { unitName := createUnitName("libpod-conmon", ctr.ID()) realCgroupParent := cgroupParent -- cgit v1.2.3-54-g00ecf