From 873014e4eee81ab090b2c97ba0ce99be7c798b75 Mon Sep 17 00:00:00 2001 From: Daniel J Walsh Date: Fri, 5 Feb 2021 06:04:30 -0500 Subject: [PATCH] Do not reset storage when running inside of a container Currently if the host shares container storage with a container running podman, the podman inside of the container resets the storage on the host. This can cause issues on the host, as well as causes the podman command running the container, to fail to unmount /dev/shm. podman run -ti --rm --privileged -v /var/lib/containers:/var/lib/containers quay.io/podman/stable podman run alpine echo hello * unlinkat /var/lib/containers/storage/overlay-containers/a7f3c9deb0656f8de1d107e7ddff2d3c3c279c11c1635f233a0bffb16051fb2c/userdata/shm: device or resource busy * unlinkat /var/lib/containers/storage/overlay-containers/a7f3c9deb0656f8de1d107e7ddff2d3c3c279c11c1635f233a0bffb16051fb2c/userdata/shm: device or resource busy Since podman is volume mounting in the graphroot, it will add a flag to /run/.containerenv to tell podman inside of container whether to reset storage or not. Since the inner podman is running inside of the container, no reason to assume this is a fresh reboot, so if "container" environment variable is set then skip reset of storage. Also added tests to make sure /run/.containerenv is runnig correctly. Fixes: https://github.com/containers/podman/issues/9191 Signed-off-by: Daniel J Walsh Signed-off-by: Matthew Heon --- libpod/container_internal_linux.go | 4 ++-- libpod/runtime.go | 37 +++++++++++++++++++++++++++--- test/e2e/run_test.go | 23 +++++++++++++++++++ 3 files changed, 59 insertions(+), 5 deletions(-) diff --git a/libpod/container_internal_linux.go b/libpod/container_internal_linux.go index 2f1bd52c4a..1da8e6c385 100644 --- a/libpod/container_internal_linux.go +++ b/libpod/container_internal_linux.go @@ -1626,7 +1626,7 @@ func (c *Container) makeBindMounts() error { // Make .containerenv if it does not exist if _, ok := c.state.BindMounts["/run/.containerenv"]; !ok { - var containerenv string + containerenv := c.runtime.graphRootMountedFlag(c.config.Spec.Mounts) isRootless := 0 if rootless.IsRootless() { isRootless = 1 @@ -1641,7 +1641,7 @@ id=%q image=%q imageid=%q rootless=%d -`, version.Version.String(), c.Name(), c.ID(), imageName, imageID, isRootless) +%s`, version.Version.String(), c.Name(), c.ID(), imageName, imageID, isRootless, containerenv) } containerenvPath, err := c.writeStringToRundir(".containerenv", containerenv) if err != nil { diff --git a/libpod/runtime.go b/libpod/runtime.go index 9ab98a27ef..7726a1f8ea 100644 --- a/libpod/runtime.go +++ b/libpod/runtime.go @@ -1,6 +1,7 @@ package libpod import ( + "bufio" "context" "fmt" "os" @@ -26,6 +27,7 @@ import ( "github.com/containers/storage" "github.com/cri-o/ocicni/pkg/ocicni" "github.com/docker/docker/pkg/namesgenerator" + spec "github.com/opencontainers/runtime-spec/specs-go" "github.com/pkg/errors" "github.com/sirupsen/logrus" ) @@ -622,9 +624,12 @@ func (r *Runtime) Shutdown(force bool) error { func (r *Runtime) refresh(alivePath string) error { logrus.Debugf("Podman detected system restart - performing state refresh") - // First clear the state in the database - if err := r.state.Refresh(); err != nil { - return err + // Clear state of database if not running in container + if !graphRootMounted() { + // First clear the state in the database + if err := r.state.Refresh(); err != nil { + return err + } } // Next refresh the state of all containers to recreate dirs and @@ -899,3 +904,29 @@ func (r *Runtime) getVolumePlugin(name string) (*plugin.VolumePlugin, error) { return plugin.GetVolumePlugin(name, pluginPath) } + +func graphRootMounted() bool { + f, err := os.OpenFile("/run/.containerenv", os.O_RDONLY, os.ModePerm) + if err != nil { + return false + } + defer f.Close() + + scanner := bufio.NewScanner(f) + for scanner.Scan() { + if scanner.Text() == "graphRootMounted=1" { + return true + } + } + return false +} + +func (r *Runtime) graphRootMountedFlag(mounts []spec.Mount) string { + root := r.store.GraphRoot() + for _, val := range mounts { + if strings.HasPrefix(root, val.Source) { + return "graphRootMounted=1" + } + } + return "" +} diff --git a/test/e2e/run_test.go b/test/e2e/run_test.go index 7d367cccf5..bff3995df7 100644 --- a/test/e2e/run_test.go +++ b/test/e2e/run_test.go @@ -47,6 +47,29 @@ var _ = Describe("Podman run", func() { Expect(session.ExitCode()).To(Equal(0)) }) + It("podman run check /run/.containerenv", func() { + session := podmanTest.Podman([]string{"run", ALPINE, "cat", "/run/.containerenv"}) + session.WaitWithDefaultTimeout() + Expect(session.ExitCode()).To(Equal(0)) + Expect(session.OutputToString()).To(Equal("")) + + session = podmanTest.Podman([]string{"run", "--privileged", "--name=test1", ALPINE, "cat", "/run/.containerenv"}) + session.WaitWithDefaultTimeout() + Expect(session.ExitCode()).To(Equal(0)) + Expect(session.OutputToString()).To(ContainSubstring("name=\"test1\"")) + Expect(session.OutputToString()).To(ContainSubstring("image=\"" + ALPINE + "\"")) + + session = podmanTest.Podman([]string{"run", "-v", "/:/host", ALPINE, "cat", "/run/.containerenv"}) + session.WaitWithDefaultTimeout() + Expect(session.ExitCode()).To(Equal(0)) + Expect(session.OutputToString()).To(ContainSubstring("graphRootMounted=1")) + + session = podmanTest.Podman([]string{"run", "-v", "/:/host", "--privileged", ALPINE, "cat", "/run/.containerenv"}) + session.WaitWithDefaultTimeout() + Expect(session.ExitCode()).To(Equal(0)) + Expect(session.OutputToString()).To(ContainSubstring("graphRootMounted=1")) + }) + It("podman run a container based on a complex local image name", func() { imageName := strings.TrimPrefix(nginx, "quay.io/") session := podmanTest.Podman([]string{"run", imageName, "ls"})