From afd0818326aa37f03a3bc74f0269a06a403db16d Mon Sep 17 00:00:00 2001 From: Giuseppe Scrivano Date: Fri, 6 Sep 2019 15:30:30 +0200 Subject: rootless: automatically create a systemd scope when running in rootless mode and using systemd as cgroup manager create automatically a systemd scope when the user doesn't own the current cgroup. This solves a couple of issues: on cgroup v2 it is necessary that a process before it can moved to a different cgroup tree must be in a directory owned by the unprivileged user. This is not always true, e.g. when creating a session with su -l. Closes: https://github.com/containers/libpod/issues/3937 Also, for running systemd in a container it was before necessary to specify "systemd-run --scope --user podman ...", now this is done automatically as part of this PR. Signed-off-by: Giuseppe Scrivano --- libpod/oci_internal_linux.go | 54 +++++++++++++++++++++++++++----------------- 1 file changed, 33 insertions(+), 21 deletions(-) (limited to 'libpod') diff --git a/libpod/oci_internal_linux.go b/libpod/oci_internal_linux.go index f9e935d86..4df1e4010 100644 --- a/libpod/oci_internal_linux.go +++ b/libpod/oci_internal_linux.go @@ -21,6 +21,7 @@ import ( "github.com/containers/libpod/pkg/cgroups" "github.com/containers/libpod/pkg/errorhandling" "github.com/containers/libpod/pkg/lookup" + "github.com/containers/libpod/pkg/rootless" "github.com/containers/libpod/pkg/util" "github.com/containers/libpod/utils" "github.com/coreos/go-systemd/activation" @@ -359,35 +360,46 @@ func startCommandGivenSelinux(cmd *exec.Cmd) error { // moveConmonToCgroupAndSignal gets a container's cgroupParent and moves the conmon process to that cgroup // it then signals for conmon to start by sending nonse data down the start fd func (r *OCIRuntime) moveConmonToCgroupAndSignal(ctr *Container, cmd *exec.Cmd, startFd *os.File, uuid string) error { + mustCreateCgroup := true // If cgroup creation is disabled - just signal. if ctr.config.NoCgroups { - return writeConmonPipeData(startFd) + mustCreateCgroup = false } - cgroupParent := ctr.CgroupParent() - if r.cgroupManager == SystemdCgroupsManager { - unitName := createUnitName("libpod-conmon", ctr.ID()) - - realCgroupParent := cgroupParent - splitParent := strings.Split(cgroupParent, "/") - if strings.HasSuffix(cgroupParent, ".slice") && len(splitParent) > 1 { - realCgroupParent = splitParent[len(splitParent)-1] + if rootless.IsRootless() { + ownsCgroup, err := cgroups.UserOwnsCurrentSystemdCgroup() + if err != nil { + return err } + mustCreateCgroup = !ownsCgroup + } - logrus.Infof("Running conmon under slice %s and unitName %s", realCgroupParent, unitName) - if err := utils.RunUnderSystemdScope(cmd.Process.Pid, realCgroupParent, unitName); err != nil { - logrus.Warnf("Failed to add conmon to systemd sandbox cgroup: %v", err) - } - } else { - cgroupPath := filepath.Join(ctr.config.CgroupParent, "conmon") - control, err := cgroups.New(cgroupPath, &spec.LinuxResources{}) - if err != nil { - logrus.Warnf("Failed to add conmon to cgroupfs sandbox cgroup: %v", err) + if mustCreateCgroup { + cgroupParent := ctr.CgroupParent() + if r.cgroupManager == SystemdCgroupsManager { + unitName := createUnitName("libpod-conmon", ctr.ID()) + + realCgroupParent := cgroupParent + splitParent := strings.Split(cgroupParent, "/") + if strings.HasSuffix(cgroupParent, ".slice") && len(splitParent) > 1 { + realCgroupParent = splitParent[len(splitParent)-1] + } + + logrus.Infof("Running conmon under slice %s and unitName %s", realCgroupParent, unitName) + if err := utils.RunUnderSystemdScope(cmd.Process.Pid, realCgroupParent, unitName); err != nil { + logrus.Warnf("Failed to add conmon to systemd sandbox cgroup: %v", err) + } } else { - // we need to remove this defer and delete the cgroup once conmon exits - // maybe need a conmon monitor? - if err := control.AddPid(cmd.Process.Pid); err != nil { + cgroupPath := filepath.Join(ctr.config.CgroupParent, "conmon") + control, err := cgroups.New(cgroupPath, &spec.LinuxResources{}) + if err != nil { logrus.Warnf("Failed to add conmon to cgroupfs sandbox cgroup: %v", err) + } else { + // we need to remove this defer and delete the cgroup once conmon exits + // maybe need a conmon monitor? + if err := control.AddPid(cmd.Process.Pid); err != nil { + logrus.Warnf("Failed to add conmon to cgroupfs sandbox cgroup: %v", err) + } } } } -- cgit v1.2.3-54-g00ecf