From 5747fd71c98238d42cf9cd307fdf4d59747a6e1d Mon Sep 17 00:00:00 2001 From: Valentin Rothberg Date: Tue, 26 Jan 2021 15:38:05 +0100 Subject: remote exec: write conmon error on hijacked connection Make sure to write error from conmon on the hijacked http connection. This fixes issues where errors were not reported on the client side, for instance, when specified command was not found on the container. To future generations: I am sorry. The code is complex, and there are many interdependencies among the concurrent goroutines. I added more complexity on top but I don't have a good idea of how to reduce complexity in the available time. Fixes: #8281 Signed-off-by: Valentin Rothberg --- libpod/oci_conmon_exec_linux.go | 48 +++++++++++++++++++++++++++++++++-------- libpod/util.go | 17 +++++++++------ 2 files changed, 49 insertions(+), 16 deletions(-) (limited to 'libpod') diff --git a/libpod/oci_conmon_exec_linux.go b/libpod/oci_conmon_exec_linux.go index dc5dd03df..faf86ea5b 100644 --- a/libpod/oci_conmon_exec_linux.go +++ b/libpod/oci_conmon_exec_linux.go @@ -126,20 +126,25 @@ func (r *ConmonOCIRuntime) ExecContainerHTTP(ctr *Container, sessionID string, o }() attachChan := make(chan error) + conmonPipeDataChan := make(chan conmonPipeData) go func() { // attachToExec is responsible for closing pipes - attachChan <- attachExecHTTP(ctr, sessionID, req, w, streams, pipes, detachKeys, options.Terminal, cancel, hijackDone, holdConnOpen) + attachChan <- attachExecHTTP(ctr, sessionID, req, w, streams, pipes, detachKeys, options.Terminal, cancel, hijackDone, holdConnOpen, execCmd, conmonPipeDataChan, ociLog) close(attachChan) }() - // Wait for conmon to succeed, when return. - if err := execCmd.Wait(); err != nil { - return -1, nil, errors.Wrapf(err, "cannot run conmon") - } + // NOTE: the channel is needed to communicate conmon's data. In case + // of an error, the error will be written on the hijacked http + // connection such that remote clients will receive the error. + pipeData := <-conmonPipeDataChan - pid, err := readConmonPipeData(pipes.syncPipe, ociLog) + return pipeData.pid, attachChan, pipeData.err +} - return pid, attachChan, err +// conmonPipeData contains the data when reading from conmon's pipe. +type conmonPipeData struct { + pid int + err error } // ExecContainerDetached executes a command in a running container, but does @@ -488,9 +493,16 @@ func (r *ConmonOCIRuntime) startExec(c *Container, sessionID string, options *Ex } // Attach to a container over HTTP -func attachExecHTTP(c *Container, sessionID string, r *http.Request, w http.ResponseWriter, streams *HTTPAttachStreams, pipes *execPipes, detachKeys []byte, isTerminal bool, cancel <-chan bool, hijackDone chan<- bool, holdConnOpen <-chan bool) (deferredErr error) { +func attachExecHTTP(c *Container, sessionID string, r *http.Request, w http.ResponseWriter, streams *HTTPAttachStreams, pipes *execPipes, detachKeys []byte, isTerminal bool, cancel <-chan bool, hijackDone chan<- bool, holdConnOpen <-chan bool, execCmd *exec.Cmd, conmonPipeDataChan chan<- conmonPipeData, ociLog string) (deferredErr error) { + // NOTE: As you may notice, the attach code is quite complex. + // Many things happen concurrently and yet are interdependent. + // If you ever change this function, make sure to write to the + // conmonPipeDataChan in case of an error. + if pipes == nil || pipes.startPipe == nil || pipes.attachPipe == nil { - return errors.Wrapf(define.ErrInvalidArg, "must provide a start and attach pipe to finish an exec attach") + err := errors.Wrapf(define.ErrInvalidArg, "must provide a start and attach pipe to finish an exec attach") + conmonPipeDataChan <- conmonPipeData{-1, err} + return err } defer func() { @@ -509,17 +521,20 @@ func attachExecHTTP(c *Container, sessionID string, r *http.Request, w http.Resp // set up the socket path, such that it is the correct length and location for exec sockPath, err := c.execAttachSocketPath(sessionID) if err != nil { + conmonPipeDataChan <- conmonPipeData{-1, err} return err } // 2: read from attachFd that the parent process has set up the console socket if _, err := readConmonPipeData(pipes.attachPipe, ""); err != nil { + conmonPipeDataChan <- conmonPipeData{-1, err} return err } // 2: then attach conn, err := openUnixSocket(sockPath) if err != nil { + conmonPipeDataChan <- conmonPipeData{-1, err} return errors.Wrapf(err, "failed to connect to container's attach socket: %v", sockPath) } defer func() { @@ -540,11 +555,13 @@ func attachExecHTTP(c *Container, sessionID string, r *http.Request, w http.Resp // Perform hijack hijacker, ok := w.(http.Hijacker) if !ok { + conmonPipeDataChan <- conmonPipeData{-1, err} return errors.Errorf("unable to hijack connection") } httpCon, httpBuf, err := hijacker.Hijack() if err != nil { + conmonPipeDataChan <- conmonPipeData{-1, err} return errors.Wrapf(err, "error hijacking connection") } @@ -555,10 +572,23 @@ func attachExecHTTP(c *Container, sessionID string, r *http.Request, w http.Resp // Force a flush after the header is written. if err := httpBuf.Flush(); err != nil { + conmonPipeDataChan <- conmonPipeData{-1, err} return errors.Wrapf(err, "error flushing HTTP hijack header") } go func() { + // Wait for conmon to succeed, when return. + if err := execCmd.Wait(); err != nil { + conmonPipeDataChan <- conmonPipeData{-1, err} + } else { + pid, err := readConmonPipeData(pipes.syncPipe, ociLog) + if err != nil { + hijackWriteError(err, c.ID(), isTerminal, httpBuf) + conmonPipeDataChan <- conmonPipeData{pid, err} + } else { + conmonPipeDataChan <- conmonPipeData{pid, err} + } + } // We need to hold the connection open until the complete exec // function has finished. This channel will be closed in a defer // in that function, so we can wait for it here. diff --git a/libpod/util.go b/libpod/util.go index bf9bf2542..391208fb9 100644 --- a/libpod/util.go +++ b/libpod/util.go @@ -235,20 +235,16 @@ func checkDependencyContainer(depCtr, ctr *Container) error { return nil } -// hijackWriteErrorAndClose writes an error to a hijacked HTTP session and -// closes it. Intended to HTTPAttach function. -// If error is nil, it will not be written; we'll only close the connection. -func hijackWriteErrorAndClose(toWrite error, cid string, terminal bool, httpCon io.Closer, httpBuf *bufio.ReadWriter) { +// hijackWriteError writes an error to a hijacked HTTP session. +func hijackWriteError(toWrite error, cid string, terminal bool, httpBuf *bufio.ReadWriter) { if toWrite != nil { - errString := []byte(fmt.Sprintf("%v\n", toWrite)) + errString := []byte(fmt.Sprintf("Error: %v\n", toWrite)) if !terminal { // We need a header. header := makeHTTPAttachHeader(2, uint32(len(errString))) if _, err := httpBuf.Write(header); err != nil { logrus.Errorf("Error writing header for container %s attach connection error: %v", cid, err) } - // TODO: May want to return immediately here to avoid - // writing garbage to the socket? } if _, err := httpBuf.Write(errString); err != nil { logrus.Errorf("Error writing error to container %s HTTP attach connection: %v", cid, err) @@ -257,6 +253,13 @@ func hijackWriteErrorAndClose(toWrite error, cid string, terminal bool, httpCon logrus.Errorf("Error flushing HTTP buffer for container %s HTTP attach connection: %v", cid, err) } } +} + +// hijackWriteErrorAndClose writes an error to a hijacked HTTP session and +// closes it. Intended to HTTPAttach function. +// If error is nil, it will not be written; we'll only close the connection. +func hijackWriteErrorAndClose(toWrite error, cid string, terminal bool, httpCon io.Closer, httpBuf *bufio.ReadWriter) { + hijackWriteError(toWrite, cid, terminal, httpBuf) if err := httpCon.Close(); err != nil { logrus.Errorf("Error closing container %s HTTP attach connection: %v", cid, err) -- cgit v1.2.3-54-g00ecf From 2393dd304de3453fabfb7eac99ef6b2fb308bd29 Mon Sep 17 00:00:00 2001 From: baude Date: Mon, 25 Jan 2021 13:58:04 -0600 Subject: Add default net info in container inspect when inspecting a container that is only connected to the default network, we should populate the default network in the container inspect information. Fixes: #6618 Signed-off-by: baude MH: Small fixes, added another test Signed-off-by: Matthew Heon --- libpod/networking_linux.go | 8 +++++--- test/e2e/inspect_test.go | 23 +++++++++++++++++++++++ 2 files changed, 28 insertions(+), 3 deletions(-) (limited to 'libpod') diff --git a/libpod/networking_linux.go b/libpod/networking_linux.go index addf1814c..94b8563fe 100644 --- a/libpod/networking_linux.go +++ b/libpod/networking_linux.go @@ -955,7 +955,7 @@ func (c *Container) getContainerNetworkInfo() (*define.InspectNetworkSettings, e if c.state.NetNS == nil { // We still want to make dummy configurations for each CNI net // the container joined. - if len(networks) > 0 && !isDefault { + if len(networks) > 0 { settings.Networks = make(map[string]*define.InspectAdditionalNetwork, len(networks)) for _, net := range networks { cniNet := new(define.InspectAdditionalNetwork) @@ -976,7 +976,7 @@ func (c *Container) getContainerNetworkInfo() (*define.InspectNetworkSettings, e } // If we have CNI networks - handle that here - if len(networks) > 0 && !isDefault { + if len(networks) > 0 { if len(networks) != len(c.state.NetworkStatus) { return nil, errors.Wrapf(define.ErrInternal, "network inspection mismatch: asked to join %d CNI network(s) %v, but have information on %d network(s)", len(networks), networks, len(c.state.NetworkStatus)) } @@ -1006,7 +1006,9 @@ func (c *Container) getContainerNetworkInfo() (*define.InspectNetworkSettings, e settings.Networks[name] = addedNet } - return settings, nil + if !isDefault { + return settings, nil + } } // If not joining networks, we should have at most 1 result diff --git a/test/e2e/inspect_test.go b/test/e2e/inspect_test.go index 97f77414e..8fc9721f9 100644 --- a/test/e2e/inspect_test.go +++ b/test/e2e/inspect_test.go @@ -443,4 +443,27 @@ var _ = Describe("Podman inspect", func() { Expect(inspect.OutputToString()).To(Equal(`"{"80/tcp":[{"HostIp":"","HostPort":"8080"}]}"`)) }) + It("Verify container inspect has default network", func() { + SkipIfRootless("Requires root CNI networking") + ctrName := "testctr" + session := podmanTest.Podman([]string{"run", "-d", "--name", ctrName, ALPINE, "top"}) + session.WaitWithDefaultTimeout() + Expect(session.ExitCode()).To(BeZero()) + + inspect := podmanTest.InspectContainer(ctrName) + Expect(len(inspect)).To(Equal(1)) + Expect(len(inspect[0].NetworkSettings.Networks)).To(Equal(1)) + }) + + It("Verify stopped container still has default network in inspect", func() { + SkipIfRootless("Requires root CNI networking") + ctrName := "testctr" + session := podmanTest.Podman([]string{"create", "--name", ctrName, ALPINE, "top"}) + session.WaitWithDefaultTimeout() + Expect(session.ExitCode()).To(BeZero()) + + inspect := podmanTest.InspectContainer(ctrName) + Expect(len(inspect)).To(Equal(1)) + Expect(len(inspect[0].NetworkSettings.Networks)).To(Equal(1)) + }) }) -- cgit v1.2.3-54-g00ecf From 0b500515d8b8900851763a17b61609556f58d99c Mon Sep 17 00:00:00 2001 From: Valentin Rothberg Date: Fri, 22 Jan 2021 15:38:51 +0100 Subject: libpod: add (*Container).ResolvePath() Add an API to libpod to resolve a path on the container. We can refactor the code that was originally written for copy. Other functions are requiring a proper path resolution, so libpod seems like a reasonable home for sharing that code. Signed-off-by: Valentin Rothberg --- libpod/container_api.go | 29 +++++++ libpod/container_path_resolution.go | 127 +++++++++++++++++++++++++++++ pkg/domain/infra/abi/archive.go | 14 +++- pkg/domain/infra/abi/containers_stat.go | 140 ++------------------------------ 4 files changed, 176 insertions(+), 134 deletions(-) create mode 100644 libpod/container_path_resolution.go (limited to 'libpod') diff --git a/libpod/container_api.go b/libpod/container_api.go index 0d62a2dd7..951227a4f 100644 --- a/libpod/container_api.go +++ b/libpod/container_api.go @@ -776,3 +776,32 @@ func (c *Container) ShouldRestart(ctx context.Context) bool { } return c.shouldRestart() } + +// ResolvePath resolves the specified path on the root for the container. The +// root must either be the mounted image of the container or the already +// mounted container storage. +// +// It returns the resolved root and the resolved path. Note that the path may +// resolve to the container's mount point or to a volume or bind mount. +func (c *Container) ResolvePath(ctx context.Context, root string, path string) (string, string, error) { + logrus.Debugf("Resolving path %q (root %q) on container %s", path, root, c.ID()) + + // Minimal sanity checks. + if len(root)*len(path) == 0 { + return "", "", errors.Wrapf(define.ErrInternal, "ResolvePath: root (%q) and path (%q) must be non empty", root, path) + } + if _, err := os.Stat(root); err != nil { + return "", "", errors.Wrapf(err, "cannot locate root to resolve path on container %s", c.ID()) + } + + if !c.batched { + c.lock.Lock() + defer c.lock.Unlock() + + if err := c.syncContainer(); err != nil { + return "", "", err + } + } + + return c.resolvePath(root, path) +} diff --git a/libpod/container_path_resolution.go b/libpod/container_path_resolution.go new file mode 100644 index 000000000..68f174278 --- /dev/null +++ b/libpod/container_path_resolution.go @@ -0,0 +1,127 @@ +package libpod + +import ( + "path/filepath" + "strings" + + securejoin "github.com/cyphar/filepath-securejoin" + "github.com/opencontainers/runtime-spec/specs-go" + "github.com/pkg/errors" + "github.com/sirupsen/logrus" +) + +// resolveContainerPaths resolves the container's mount point and the container +// path as specified by the user. Both may resolve to paths outside of the +// container's mount point when the container path hits a volume or bind mount. +func (container *Container) resolvePath(mountPoint string, containerPath string) (string, string, error) { + // Let's first make sure we have a path relative to the mount point. + pathRelativeToContainerMountPoint := containerPath + if !filepath.IsAbs(containerPath) { + // If the containerPath is not absolute, it's relative to the + // container's working dir. To be extra careful, let's first + // join the working dir with "/", and the add the containerPath + // to it. + pathRelativeToContainerMountPoint = filepath.Join(filepath.Join("/", container.WorkingDir()), containerPath) + } + resolvedPathOnTheContainerMountPoint := filepath.Join(mountPoint, pathRelativeToContainerMountPoint) + pathRelativeToContainerMountPoint = strings.TrimPrefix(pathRelativeToContainerMountPoint, mountPoint) + pathRelativeToContainerMountPoint = filepath.Join("/", pathRelativeToContainerMountPoint) + + // Now we have an "absolute container Path" but not yet resolved on the + // host (e.g., "/foo/bar/file.txt"). As mentioned above, we need to + // check if "/foo/bar/file.txt" is on a volume or bind mount. To do + // that, we need to walk *down* the paths to the root. Assuming + // volume-1 is mounted to "/foo" and volume-2 is mounted to "/foo/bar", + // we must select "/foo/bar". Once selected, we need to rebase the + // remainder (i.e, "/file.txt") on the volume's mount point on the + // host. Same applies to bind mounts. + + searchPath := pathRelativeToContainerMountPoint + for { + volume, err := findVolume(container, searchPath) + if err != nil { + return "", "", err + } + if volume != nil { + logrus.Debugf("Container path %q resolved to volume %q on path %q", containerPath, volume.Name(), searchPath) + + // TODO: We really need to force the volume to mount + // before doing this, but that API is not exposed + // externally right now and doing so is beyond the scope + // of this commit. + mountPoint, err := volume.MountPoint() + if err != nil { + return "", "", err + } + if mountPoint == "" { + return "", "", errors.Errorf("volume %s is not mounted, cannot copy into it", volume.Name()) + } + + // We found a matching volume for searchPath. We now + // need to first find the relative path of our input + // path to the searchPath, and then join it with the + // volume's mount point. + pathRelativeToVolume := strings.TrimPrefix(pathRelativeToContainerMountPoint, searchPath) + absolutePathOnTheVolumeMount, err := securejoin.SecureJoin(mountPoint, pathRelativeToVolume) + if err != nil { + return "", "", err + } + return mountPoint, absolutePathOnTheVolumeMount, nil + } + + if mount := findBindMount(container, searchPath); mount != nil { + logrus.Debugf("Container path %q resolved to bind mount %q:%q on path %q", containerPath, mount.Source, mount.Destination, searchPath) + // We found a matching bind mount for searchPath. We + // now need to first find the relative path of our + // input path to the searchPath, and then join it with + // the source of the bind mount. + pathRelativeToBindMount := strings.TrimPrefix(pathRelativeToContainerMountPoint, searchPath) + absolutePathOnTheBindMount, err := securejoin.SecureJoin(mount.Source, pathRelativeToBindMount) + if err != nil { + return "", "", err + } + return mount.Source, absolutePathOnTheBindMount, nil + + } + + if searchPath == "/" { + // Cannot go beyond "/", so we're done. + break + } + + // Walk *down* the path (e.g., "/foo/bar/x" -> "/foo/bar"). + searchPath = filepath.Dir(searchPath) + } + + // No volume, no bind mount but just a normal path on the container. + return mountPoint, resolvedPathOnTheContainerMountPoint, nil +} + +// findVolume checks if the specified container path matches a volume inside +// the container. It returns a matching volume or nil. +func findVolume(c *Container, containerPath string) (*Volume, error) { + runtime := c.Runtime() + cleanedContainerPath := filepath.Clean(containerPath) + for _, vol := range c.Config().NamedVolumes { + if cleanedContainerPath == filepath.Clean(vol.Dest) { + return runtime.GetVolume(vol.Name) + } + } + return nil, nil +} + +// findBindMount checks if the specified container path matches a bind mount +// inside the container. It returns a matching mount or nil. +func findBindMount(c *Container, containerPath string) *specs.Mount { + cleanedPath := filepath.Clean(containerPath) + for _, m := range c.Config().Spec.Mounts { + if m.Type != "bind" { + continue + } + if cleanedPath == filepath.Clean(m.Destination) { + mount := m + return &mount + } + } + return nil +} diff --git a/pkg/domain/infra/abi/archive.go b/pkg/domain/infra/abi/archive.go index 809813756..c64dfb02a 100644 --- a/pkg/domain/infra/abi/archive.go +++ b/pkg/domain/infra/abi/archive.go @@ -26,13 +26,18 @@ func (ic *ContainerEngine) ContainerCopyFromArchive(ctx context.Context, nameOrI return nil, err } + containerMountPoint, err := container.Mount() + if err != nil { + return nil, err + } + unmount := func() { if err := container.Unmount(false); err != nil { logrus.Errorf("Error unmounting container: %v", err) } } - _, resolvedRoot, resolvedContainerPath, err := ic.containerStat(container, containerPath) + _, resolvedRoot, resolvedContainerPath, err := ic.containerStat(container, containerMountPoint, containerPath) if err != nil { unmount() return nil, err @@ -71,6 +76,11 @@ func (ic *ContainerEngine) ContainerCopyToArchive(ctx context.Context, nameOrID return nil, err } + containerMountPoint, err := container.Mount() + if err != nil { + return nil, err + } + unmount := func() { if err := container.Unmount(false); err != nil { logrus.Errorf("Error unmounting container: %v", err) @@ -83,7 +93,7 @@ func (ic *ContainerEngine) ContainerCopyToArchive(ctx context.Context, nameOrID containerPath = "/." } - _, resolvedRoot, resolvedContainerPath, err := ic.containerStat(container, containerPath) + _, resolvedRoot, resolvedContainerPath, err := ic.containerStat(container, containerMountPoint, containerPath) if err != nil { unmount() return nil, err diff --git a/pkg/domain/infra/abi/containers_stat.go b/pkg/domain/infra/abi/containers_stat.go index 931e77026..f3d0799a0 100644 --- a/pkg/domain/infra/abi/containers_stat.go +++ b/pkg/domain/infra/abi/containers_stat.go @@ -10,18 +10,11 @@ import ( "github.com/containers/podman/v2/libpod" "github.com/containers/podman/v2/pkg/copy" "github.com/containers/podman/v2/pkg/domain/entities" - securejoin "github.com/cyphar/filepath-securejoin" - "github.com/opencontainers/runtime-spec/specs-go" "github.com/pkg/errors" "github.com/sirupsen/logrus" ) -func (ic *ContainerEngine) containerStat(container *libpod.Container, containerPath string) (*entities.ContainerStatReport, string, string, error) { - containerMountPoint, err := container.Mount() - if err != nil { - return nil, "", "", err - } - +func (ic *ContainerEngine) containerStat(container *libpod.Container, containerMountPoint string, containerPath string) (*entities.ContainerStatReport, string, string, error) { // Make sure that "/" copies the *contents* of the mount point and not // the directory. if containerPath == "/" { @@ -30,7 +23,7 @@ func (ic *ContainerEngine) containerStat(container *libpod.Container, containerP // Now resolve the container's path. It may hit a volume, it may hit a // bind mount, it may be relative. - resolvedRoot, resolvedContainerPath, err := resolveContainerPaths(container, containerMountPoint, containerPath) + resolvedRoot, resolvedContainerPath, err := container.ResolvePath(context.Background(), containerMountPoint, containerPath) if err != nil { return nil, "", "", err } @@ -94,138 +87,21 @@ func (ic *ContainerEngine) ContainerStat(ctx context.Context, nameOrID string, c return nil, err } + containerMountPoint, err := container.Mount() + if err != nil { + return nil, err + } + defer func() { if err := container.Unmount(false); err != nil { logrus.Errorf("Error unmounting container: %v", err) } }() - statReport, _, _, err := ic.containerStat(container, containerPath) + statReport, _, _, err := ic.containerStat(container, containerMountPoint, containerPath) return statReport, err } -// resolveContainerPaths resolves the container's mount point and the container -// path as specified by the user. Both may resolve to paths outside of the -// container's mount point when the container path hits a volume or bind mount. -// -// NOTE: We must take volumes and bind mounts into account as, regrettably, we -// can copy to/from stopped containers. In that case, the volumes and bind -// mounts are not present. For running containers, the runtime (e.g., runc or -// crun) takes care of these mounts. For stopped ones, we need to do quite -// some dance, as done below. -func resolveContainerPaths(container *libpod.Container, mountPoint string, containerPath string) (string, string, error) { - // Let's first make sure we have a path relative to the mount point. - pathRelativeToContainerMountPoint := containerPath - if !filepath.IsAbs(containerPath) { - // If the containerPath is not absolute, it's relative to the - // container's working dir. To be extra careful, let's first - // join the working dir with "/", and the add the containerPath - // to it. - pathRelativeToContainerMountPoint = filepath.Join(filepath.Join("/", container.WorkingDir()), containerPath) - } - resolvedPathOnTheContainerMountPoint := filepath.Join(mountPoint, pathRelativeToContainerMountPoint) - pathRelativeToContainerMountPoint = strings.TrimPrefix(pathRelativeToContainerMountPoint, mountPoint) - pathRelativeToContainerMountPoint = filepath.Join("/", pathRelativeToContainerMountPoint) - - // Now we have an "absolute container Path" but not yet resolved on the - // host (e.g., "/foo/bar/file.txt"). As mentioned above, we need to - // check if "/foo/bar/file.txt" is on a volume or bind mount. To do - // that, we need to walk *down* the paths to the root. Assuming - // volume-1 is mounted to "/foo" and volume-2 is mounted to "/foo/bar", - // we must select "/foo/bar". Once selected, we need to rebase the - // remainder (i.e, "/file.txt") on the volume's mount point on the - // host. Same applies to bind mounts. - - searchPath := pathRelativeToContainerMountPoint - for { - volume, err := findVolume(container, searchPath) - if err != nil { - return "", "", err - } - if volume != nil { - logrus.Debugf("Container path %q resolved to volume %q on path %q", containerPath, volume.Name(), searchPath) - - // TODO: We really need to force the volume to mount - // before doing this, but that API is not exposed - // externally right now and doing so is beyond the scope - // of this commit. - mountPoint, err := volume.MountPoint() - if err != nil { - return "", "", err - } - if mountPoint == "" { - return "", "", errors.Errorf("volume %s is not mounted, cannot copy into it", volume.Name()) - } - - // We found a matching volume for searchPath. We now - // need to first find the relative path of our input - // path to the searchPath, and then join it with the - // volume's mount point. - pathRelativeToVolume := strings.TrimPrefix(pathRelativeToContainerMountPoint, searchPath) - absolutePathOnTheVolumeMount, err := securejoin.SecureJoin(mountPoint, pathRelativeToVolume) - if err != nil { - return "", "", err - } - return mountPoint, absolutePathOnTheVolumeMount, nil - } - - if mount := findBindMount(container, searchPath); mount != nil { - logrus.Debugf("Container path %q resolved to bind mount %q:%q on path %q", containerPath, mount.Source, mount.Destination, searchPath) - // We found a matching bind mount for searchPath. We - // now need to first find the relative path of our - // input path to the searchPath, and then join it with - // the source of the bind mount. - pathRelativeToBindMount := strings.TrimPrefix(pathRelativeToContainerMountPoint, searchPath) - absolutePathOnTheBindMount, err := securejoin.SecureJoin(mount.Source, pathRelativeToBindMount) - if err != nil { - return "", "", err - } - return mount.Source, absolutePathOnTheBindMount, nil - - } - - if searchPath == "/" { - // Cannot go beyond "/", so we're done. - break - } - - // Walk *down* the path (e.g., "/foo/bar/x" -> "/foo/bar"). - searchPath = filepath.Dir(searchPath) - } - - // No volume, no bind mount but just a normal path on the container. - return mountPoint, resolvedPathOnTheContainerMountPoint, nil -} - -// findVolume checks if the specified container path matches a volume inside -// the container. It returns a matching volume or nil. -func findVolume(c *libpod.Container, containerPath string) (*libpod.Volume, error) { - runtime := c.Runtime() - cleanedContainerPath := filepath.Clean(containerPath) - for _, vol := range c.Config().NamedVolumes { - if cleanedContainerPath == filepath.Clean(vol.Dest) { - return runtime.GetVolume(vol.Name) - } - } - return nil, nil -} - -// findBindMount checks if the specified container path matches a bind mount -// inside the container. It returns a matching mount or nil. -func findBindMount(c *libpod.Container, containerPath string) *specs.Mount { - cleanedPath := filepath.Clean(containerPath) - for _, m := range c.Config().Spec.Mounts { - if m.Type != "bind" { - continue - } - if cleanedPath == filepath.Clean(m.Destination) { - mount := m - return &mount - } - } - return nil -} - // secureStat extracts file info for path in a chroot'ed environment in root. func secureStat(root string, path string) (*buildahCopiah.StatForItem, error) { var glob string -- cgit v1.2.3-54-g00ecf From c48753bfa0d56b855f71dc6ad62e8eff62cf98e1 Mon Sep 17 00:00:00 2001 From: Valentin Rothberg Date: Thu, 21 Jan 2021 15:41:14 +0100 Subject: workdir presence checks A container's workdir can be specified via the CLI via `--workdir` and via an image config with the CLI having precedence. Since images have a tendency to specify workdirs without necessarily shipping the paths with the root FS, make sure that Podman creates the workdir. When specified via the CLI, do not create the path, but check for its existence and return a human-friendly error. NOTE: `crun` is performing a similar check that would yield exit code 127. With this change, however, Podman performs the check and yields exit code 126. Since this is specific to `crun`, I do not consider it to be a breaking change of Podman. Fixes: #9040 Signed-off-by: Valentin Rothberg --- libpod/container_internal_linux.go | 63 +++++++++++++++++++++++++------- libpod/container_path_resolution.go | 47 ++++++++++++++++++++++-- pkg/specgen/generate/container.go | 14 ------- pkg/specgen/generate/container_create.go | 12 +++++- test/e2e/run_working_dir_test.go | 6 +-- test/system/030-run.bats | 21 +++++++++++ test/system/070-build.bats | 4 +- 7 files changed, 127 insertions(+), 40 deletions(-) (limited to 'libpod') diff --git a/libpod/container_internal_linux.go b/libpod/container_internal_linux.go index 0553cc59c..9c5989d23 100644 --- a/libpod/container_internal_linux.go +++ b/libpod/container_internal_linux.go @@ -174,25 +174,60 @@ func (c *Container) prepare() error { return err } - // Ensure container entrypoint is created (if required) - if c.config.CreateWorkingDir { - workdir, err := securejoin.SecureJoin(c.state.Mountpoint, c.WorkingDir()) - if err != nil { - return errors.Wrapf(err, "error creating path to container %s working dir", c.ID()) - } - rootUID := c.RootUID() - rootGID := c.RootGID() + // Make sure the workdir exists + if err := c.resolveWorkDir(); err != nil { + return err + } - if err := os.MkdirAll(workdir, 0755); err != nil { - if os.IsExist(err) { - return nil + return nil +} + +// resolveWorkDir resolves the container's workdir and, depending on the +// configuration, will create it, or error out if it does not exist. +// Note that the container must be mounted before. +func (c *Container) resolveWorkDir() error { + workdir := c.WorkingDir() + + // If the specified workdir is a subdir of a volume or mount, + // we don't need to do anything. The runtime is taking care of + // that. + if isPathOnVolume(c, workdir) || isPathOnBindMount(c, workdir) { + logrus.Debugf("Workdir %q resolved to a volume or mount", workdir) + return nil + } + + _, resolvedWorkdir, err := c.resolvePath(c.state.Mountpoint, workdir) + if err != nil { + return err + } + logrus.Debugf("Workdir %q resolved to host path %q", workdir, resolvedWorkdir) + + // No need to create it (e.g., `--workdir=/foo`), so let's make sure + // the path exists on the container. + if !c.config.CreateWorkingDir { + if _, err := os.Stat(resolvedWorkdir); err != nil { + if os.IsNotExist(err) { + return errors.Errorf("workdir %q does not exist on container %s", workdir, c.ID()) } - return errors.Wrapf(err, "error creating container %s working dir", c.ID()) + // This might be a serious error (e.g., permission), so + // we need to return the full error. + return errors.Wrapf(err, "error detecting workdir %q on container %s", workdir, c.ID()) } + } + + // Ensure container entrypoint is created (if required). + rootUID := c.RootUID() + rootGID := c.RootGID() - if err := os.Chown(workdir, rootUID, rootGID); err != nil { - return errors.Wrapf(err, "error chowning container %s working directory to container root", c.ID()) + if err := os.MkdirAll(resolvedWorkdir, 0755); err != nil { + if os.IsExist(err) { + return nil } + return errors.Wrapf(err, "error creating container %s workdir", c.ID()) + } + + if err := os.Chown(resolvedWorkdir, rootUID, rootGID); err != nil { + return errors.Wrapf(err, "error chowning container %s workdir to container root", c.ID()) } return nil diff --git a/libpod/container_path_resolution.go b/libpod/container_path_resolution.go index 68f174278..805b3b947 100644 --- a/libpod/container_path_resolution.go +++ b/libpod/container_path_resolution.go @@ -13,6 +13,11 @@ import ( // resolveContainerPaths resolves the container's mount point and the container // path as specified by the user. Both may resolve to paths outside of the // container's mount point when the container path hits a volume or bind mount. +// +// It returns a bool, indicating whether containerPath resolves outside of +// mountPoint (e.g., via a mount or volume), the resolved root (e.g., container +// mount, bind mount or volume) and the resolved path on the root (absolute to +// the host). func (container *Container) resolvePath(mountPoint string, containerPath string) (string, string, error) { // Let's first make sure we have a path relative to the mount point. pathRelativeToContainerMountPoint := containerPath @@ -97,8 +102,8 @@ func (container *Container) resolvePath(mountPoint string, containerPath string) return mountPoint, resolvedPathOnTheContainerMountPoint, nil } -// findVolume checks if the specified container path matches a volume inside -// the container. It returns a matching volume or nil. +// findVolume checks if the specified containerPath matches the destination +// path of a Volume. Returns a matching Volume or nil. func findVolume(c *Container, containerPath string) (*Volume, error) { runtime := c.Runtime() cleanedContainerPath := filepath.Clean(containerPath) @@ -110,8 +115,25 @@ func findVolume(c *Container, containerPath string) (*Volume, error) { return nil, nil } -// findBindMount checks if the specified container path matches a bind mount -// inside the container. It returns a matching mount or nil. +// isPathOnVolume returns true if the specified containerPath is a subdir of any +// Volume's destination. +func isPathOnVolume(c *Container, containerPath string) bool { + cleanedContainerPath := filepath.Clean(containerPath) + for _, vol := range c.Config().NamedVolumes { + if cleanedContainerPath == filepath.Clean(vol.Dest) { + return true + } + for dest := vol.Dest; dest != "/"; dest = filepath.Dir(dest) { + if cleanedContainerPath == dest { + return true + } + } + } + return false +} + +// findBindMounts checks if the specified containerPath matches the destination +// path of a Mount. Returns a matching Mount or nil. func findBindMount(c *Container, containerPath string) *specs.Mount { cleanedPath := filepath.Clean(containerPath) for _, m := range c.Config().Spec.Mounts { @@ -125,3 +147,20 @@ func findBindMount(c *Container, containerPath string) *specs.Mount { } return nil } + +/// isPathOnBindMount returns true if the specified containerPath is a subdir of any +// Mount's destination. +func isPathOnBindMount(c *Container, containerPath string) bool { + cleanedContainerPath := filepath.Clean(containerPath) + for _, m := range c.Config().Spec.Mounts { + if cleanedContainerPath == filepath.Clean(m.Destination) { + return true + } + for dest := m.Destination; dest != "/"; dest = filepath.Dir(dest) { + if cleanedContainerPath == dest { + return true + } + } + } + return false +} diff --git a/pkg/specgen/generate/container.go b/pkg/specgen/generate/container.go index cc3f7928c..31d317bf8 100644 --- a/pkg/specgen/generate/container.go +++ b/pkg/specgen/generate/container.go @@ -203,20 +203,6 @@ func CompleteSpec(ctx context.Context, r *libpod.Runtime, s *specgen.SpecGenerat } s.Annotations = annotations - // workdir - if s.WorkDir == "" { - if newImage != nil { - workingDir, err := newImage.WorkingDir(ctx) - if err != nil { - return nil, err - } - s.WorkDir = workingDir - } - } - if s.WorkDir == "" { - s.WorkDir = "/" - } - if len(s.SeccompProfilePath) < 1 { p, err := libpod.DefaultSeccompPath() if err != nil { diff --git a/pkg/specgen/generate/container_create.go b/pkg/specgen/generate/container_create.go index 4f36744ca..1bc050b00 100644 --- a/pkg/specgen/generate/container_create.go +++ b/pkg/specgen/generate/container_create.go @@ -272,10 +272,18 @@ func createContainerOptions(ctx context.Context, rt *libpod.Runtime, s *specgen. if s.Entrypoint != nil { options = append(options, libpod.WithEntrypoint(s.Entrypoint)) } - // If the user did not set an workdir but the image did, ensure it is - // created. + // If the user did not specify a workdir on the CLI, let's extract it + // from the image. if s.WorkDir == "" && img != nil { options = append(options, libpod.WithCreateWorkingDir()) + wd, err := img.WorkingDir(ctx) + if err != nil { + return nil, err + } + s.WorkDir = wd + } + if s.WorkDir == "" { + s.WorkDir = "/" } if s.StopSignal != nil { options = append(options, libpod.WithStopSignal(*s.StopSignal)) diff --git a/test/e2e/run_working_dir_test.go b/test/e2e/run_working_dir_test.go index 7d8db361c..59538448e 100644 --- a/test/e2e/run_working_dir_test.go +++ b/test/e2e/run_working_dir_test.go @@ -2,7 +2,6 @@ package integration import ( "os" - "strings" . "github.com/containers/podman/v2/test/utils" . "github.com/onsi/ginkgo" @@ -41,12 +40,9 @@ var _ = Describe("Podman run", func() { }) It("podman run a container using non existing --workdir", func() { - if !strings.Contains(podmanTest.OCIRuntime, "crun") { - Skip("Test only works on crun") - } session := podmanTest.Podman([]string{"run", "--workdir", "/home/foobar", ALPINE, "pwd"}) session.WaitWithDefaultTimeout() - Expect(session.ExitCode()).To(Equal(127)) + Expect(session.ExitCode()).To(Equal(126)) }) It("podman run a container on an image with a workdir", func() { diff --git a/test/system/030-run.bats b/test/system/030-run.bats index 29dc95dc3..dcf1da370 100644 --- a/test/system/030-run.bats +++ b/test/system/030-run.bats @@ -589,4 +589,25 @@ json-file | f is "${lines[1]}" "$rand" "Container runs successfully despite warning" } +@test "podman run - check workdir" { + # Workdirs specified via the CLI are not created on the root FS. + run_podman 126 run --rm --workdir /i/do/not/exist $IMAGE pwd + # Note: remote error prepends an attach error. + is "$output" "Error: .*workdir \"/i/do/not/exist\" does not exist on container.*" + + testdir=$PODMAN_TMPDIR/volume + mkdir -p $testdir + randomcontent=$(random_string 10) + echo "$randomcontent" > $testdir/content + + # Workdir does not exist on the image but is volume mounted. + run_podman run --rm --workdir /IamNotOnTheImage -v $testdir:/IamNotOnTheImage $IMAGE cat content + is "$output" "$randomcontent" "cat random content" + + # Workdir does not exist on the image but is created by the runtime as it's + # a subdir of a volume. + run_podman run --rm --workdir /IamNotOntheImage -v $testdir/content:/IamNotOntheImage/foo $IMAGE cat foo + is "$output" "$randomcontent" "cat random content" +} + # vim: filetype=sh diff --git a/test/system/070-build.bats b/test/system/070-build.bats index 0e83a184b..bf9fa789c 100644 --- a/test/system/070-build.bats +++ b/test/system/070-build.bats @@ -145,10 +145,12 @@ EOF https_proxy=https-proxy-in-env-file EOF + # NOTE: it's important to not create the workdir. + # Podman will make sure to create a missing workdir + # if needed. See #9040. cat >$tmpdir/Containerfile < Date: Mon, 25 Jan 2021 15:29:00 -0500 Subject: Ensure shutdown handler access is syncronized There was a potential race where two handlers could be added at the same time. Go Maps are not thread-safe, so that could do unpleasant things. Add a mutex to keep things safe. Also, swap the order or Register and Start for the handlers in Libpod runtime created. As written, there was a small gap between Start and Register where SIGTERM/SIGINT would be completely ignored, instead of stopping Podman. Swapping the two closes this gap. Signed-off-by: Matthew Heon --- libpod/runtime.go | 14 +++++++------- libpod/shutdown/handler.go | 10 ++++++++++ pkg/api/server/server.go | 8 ++++---- 3 files changed, 21 insertions(+), 11 deletions(-) (limited to 'libpod') diff --git a/libpod/runtime.go b/libpod/runtime.go index 34c737a67..0dc220b52 100644 --- a/libpod/runtime.go +++ b/libpod/runtime.go @@ -180,6 +180,13 @@ func newRuntimeFromConfig(ctx context.Context, conf *config.Config, options ...R } } + if err := shutdown.Register("libpod", func(sig os.Signal) error { + os.Exit(1) + return nil + }); err != nil && errors.Cause(err) != shutdown.ErrHandlerExists { + logrus.Errorf("Error registering shutdown handler for libpod: %v", err) + } + if err := shutdown.Start(); err != nil { return nil, errors.Wrapf(err, "error starting shutdown signal handler") } @@ -188,13 +195,6 @@ func newRuntimeFromConfig(ctx context.Context, conf *config.Config, options ...R return nil, err } - if err := shutdown.Register("libpod", func(sig os.Signal) error { - os.Exit(1) - return nil - }); err != nil && errors.Cause(err) != shutdown.ErrHandlerExists { - logrus.Errorf("Error registering shutdown handler for libpod: %v", err) - } - return runtime, nil } diff --git a/libpod/shutdown/handler.go b/libpod/shutdown/handler.go index f0f228b19..ac1d33910 100644 --- a/libpod/shutdown/handler.go +++ b/libpod/shutdown/handler.go @@ -18,6 +18,8 @@ var ( stopped bool sigChan chan os.Signal cancelChan chan bool + // Syncronize accesses to the map + handlerLock sync.Mutex // Definitions of all on-shutdown handlers handlers map[string]func(os.Signal) error // Ordering that on-shutdown handlers will be invoked. @@ -50,6 +52,7 @@ func Start() error { case sig := <-sigChan: logrus.Infof("Received shutdown signal %v, terminating!", sig) shutdownInhibit.Lock() + handlerLock.Lock() for _, name := range handlerOrder { handler, ok := handlers[name] if !ok { @@ -61,6 +64,7 @@ func Start() error { logrus.Errorf("Error running shutdown handler %s: %v", name, err) } } + handlerLock.Unlock() shutdownInhibit.Unlock() return } @@ -97,6 +101,9 @@ func Uninhibit() { // by a signal. Handlers are invoked LIFO - the last handler registered is the // first run. func Register(name string, handler func(os.Signal) error) error { + handlerLock.Lock() + defer handlerLock.Unlock() + if handlers == nil { handlers = make(map[string]func(os.Signal) error) } @@ -113,6 +120,9 @@ func Register(name string, handler func(os.Signal) error) error { // Unregister un-registers a given shutdown handler. func Unregister(name string) error { + handlerLock.Lock() + defer handlerLock.Unlock() + if handlers == nil { return nil } diff --git a/pkg/api/server/server.go b/pkg/api/server/server.go index 046f6561c..d612041f6 100644 --- a/pkg/api/server/server.go +++ b/pkg/api/server/server.go @@ -179,15 +179,15 @@ func setupSystemd() { func (s *APIServer) Serve() error { setupSystemd() - // Start the shutdown signal handler. - if err := shutdown.Start(); err != nil { - return err - } if err := shutdown.Register("server", func(sig os.Signal) error { return s.Shutdown() }); err != nil { return err } + // Start the shutdown signal handler. + if err := shutdown.Start(); err != nil { + return err + } errChan := make(chan error, 1) -- cgit v1.2.3-54-g00ecf