// +build linux package libpod import ( "context" "fmt" "io" "io/ioutil" "math" "net" "os" "os/user" "path" "path/filepath" "strconv" "strings" "sync" "syscall" "time" metadata "github.com/checkpoint-restore/checkpointctl/lib" cnitypes "github.com/containernetworking/cni/pkg/types/current" "github.com/containernetworking/plugins/pkg/ns" "github.com/containers/buildah/pkg/chrootuser" "github.com/containers/buildah/pkg/overlay" butil "github.com/containers/buildah/util" "github.com/containers/common/pkg/apparmor" "github.com/containers/common/pkg/chown" "github.com/containers/common/pkg/config" "github.com/containers/common/pkg/subscriptions" "github.com/containers/common/pkg/umask" "github.com/containers/podman/v3/libpod/define" "github.com/containers/podman/v3/libpod/events" "github.com/containers/podman/v3/pkg/annotations" "github.com/containers/podman/v3/pkg/cgroups" "github.com/containers/podman/v3/pkg/checkpoint/crutils" "github.com/containers/podman/v3/pkg/criu" "github.com/containers/podman/v3/pkg/lookup" "github.com/containers/podman/v3/pkg/resolvconf" "github.com/containers/podman/v3/pkg/rootless" "github.com/containers/podman/v3/pkg/util" "github.com/containers/podman/v3/utils" "github.com/containers/podman/v3/version" "github.com/containers/storage/pkg/archive" "github.com/containers/storage/pkg/idtools" securejoin "github.com/cyphar/filepath-securejoin" runcuser "github.com/opencontainers/runc/libcontainer/user" spec "github.com/opencontainers/runtime-spec/specs-go" "github.com/opencontainers/runtime-tools/generate" "github.com/opencontainers/selinux/go-selinux/label" "github.com/pkg/errors" "github.com/sirupsen/logrus" "golang.org/x/sys/unix" ) func (c *Container) mountSHM(shmOptions string) error { if err := unix.Mount("shm", c.config.ShmDir, "tmpfs", unix.MS_NOEXEC|unix.MS_NOSUID|unix.MS_NODEV, label.FormatMountLabel(shmOptions, c.config.MountLabel)); err != nil { return errors.Wrapf(err, "failed to mount shm tmpfs %q", c.config.ShmDir) } return nil } func (c *Container) unmountSHM(mount string) error { if err := unix.Unmount(mount, 0); err != nil { if err != syscall.EINVAL && err != syscall.ENOENT { return errors.Wrapf(err, "error unmounting container %s SHM mount %s", c.ID(), mount) } // If it's just an EINVAL or ENOENT, debug logs only logrus.Debugf("container %s failed to unmount %s : %v", c.ID(), mount, err) } return nil } // prepare mounts the container and sets up other required resources like net // namespaces func (c *Container) prepare() error { var ( wg sync.WaitGroup netNS ns.NetNS networkStatus []*cnitypes.Result createNetNSErr, mountStorageErr error mountPoint string tmpStateLock sync.Mutex ) wg.Add(2) go func() { defer wg.Done() // Set up network namespace if not already set up noNetNS := c.state.NetNS == nil if c.config.CreateNetNS && noNetNS && !c.config.PostConfigureNetNS { if rootless.IsRootless() && len(c.config.Networks) > 0 { netNS, networkStatus, createNetNSErr = AllocRootlessCNI(context.Background(), c) } else { netNS, networkStatus, createNetNSErr = c.runtime.createNetNS(c) } if createNetNSErr != nil { return } tmpStateLock.Lock() defer tmpStateLock.Unlock() // Assign NetNS attributes to container c.state.NetNS = netNS c.state.NetworkStatus = networkStatus } // handle rootless network namespace setup if noNetNS && !c.config.PostConfigureNetNS { if rootless.IsRootless() { createNetNSErr = c.runtime.setupRootlessNetNS(c) } else if c.config.NetMode.IsSlirp4netns() { createNetNSErr = c.runtime.setupSlirp4netns(c) } } }() // Mount storage if not mounted go func() { defer wg.Done() mountPoint, mountStorageErr = c.mountStorage() if mountStorageErr != nil { return } tmpStateLock.Lock() defer tmpStateLock.Unlock() // Finish up mountStorage c.state.Mounted = true c.state.Mountpoint = mountPoint logrus.Debugf("Created root filesystem for container %s at %s", c.ID(), c.state.Mountpoint) }() wg.Wait() var createErr error if createNetNSErr != nil { createErr = createNetNSErr } if mountStorageErr != nil { if createErr != nil { logrus.Errorf("Error preparing container %s: %v", c.ID(), createErr) } createErr = mountStorageErr } // Only trigger storage cleanup if mountStorage was successful. // Otherwise, we may mess up mount counters. if createNetNSErr != nil && mountStorageErr == nil { if err := c.cleanupStorage(); err != nil { // createErr is guaranteed non-nil, so print // unconditionally logrus.Errorf("Error preparing container %s: %v", c.ID(), createErr) createErr = errors.Wrapf(err, "error unmounting storage for container %s after network create failure", c.ID()) } } // It's OK to unconditionally trigger network cleanup. If the network // isn't ready it will do nothing. if createErr != nil { if err := c.cleanupNetwork(); err != nil { logrus.Errorf("Error preparing container %s: %v", c.ID(), createErr) createErr = errors.Wrapf(err, "error cleaning up container %s network after setup failure", c.ID()) } } if createErr != nil { return createErr } // Save changes to container state if err := c.save(); err != nil { return err } // Make sure the workdir exists if err := c.resolveWorkDir(); err != nil { return err } 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) st, err := os.Stat(resolvedWorkdir) if err == nil { if !st.IsDir() { return errors.Errorf("workdir %q exists on container %s, but is not a directory", workdir, c.ID()) } return nil } if !c.config.CreateWorkingDir { // No need to create it (e.g., `--workdir=/foo`), so let's make sure // the path exists on the container. if err != nil { if os.IsNotExist(err) { return errors.Errorf("workdir %q does not exist on container %s", workdir, 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()) } return nil } 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()) } // Ensure container entrypoint is created (if required). uid, gid, _, err := chrootuser.GetUser(c.state.Mountpoint, c.User()) if err != nil { return errors.Wrapf(err, "error looking up %s inside of the container %s", c.User(), c.ID()) } if err := os.Chown(resolvedWorkdir, int(uid), int(gid)); err != nil { return errors.Wrapf(err, "error chowning container %s workdir to container root", c.ID()) } return nil } // cleanupNetwork unmounts and cleans up the container's network func (c *Container) cleanupNetwork() error { if c.config.NetNsCtr != "" { return nil } netDisabled, err := c.NetworkDisabled() if err != nil { return err } if netDisabled { return nil } if c.state.NetNS == nil { logrus.Debugf("Network is already cleaned up, skipping...") return nil } // Stop the container's network namespace (if it has one) if err := c.runtime.teardownNetNS(c); err != nil { logrus.Errorf("unable to cleanup network for container %s: %q", c.ID(), err) } c.state.NetNS = nil c.state.NetworkStatus = nil if c.valid { return c.save() } return nil } // reloadNetwork reloads the network for the given container, recreating // firewall rules. func (c *Container) reloadNetwork() error { result, err := c.runtime.reloadContainerNetwork(c) if err != nil { return err } c.state.NetworkStatus = result return c.save() } func (c *Container) getUserOverrides() *lookup.Overrides { var hasPasswdFile, hasGroupFile bool overrides := lookup.Overrides{} for _, m := range c.config.Spec.Mounts { if m.Destination == "/etc/passwd" { overrides.ContainerEtcPasswdPath = m.Source hasPasswdFile = true } if m.Destination == "/etc/group" { overrides.ContainerEtcGroupPath = m.Source hasGroupFile = true } if m.Destination == "/etc" { if !hasPasswdFile { overrides.ContainerEtcPasswdPath = filepath.Join(m.Source, "passwd") } if !hasGroupFile { overrides.ContainerEtcGroupPath = filepath.Join(m.Source, "group") } } } if path, ok := c.state.BindMounts["/etc/passwd"]; ok { overrides.ContainerEtcPasswdPath = path } return &overrides } // Generate spec for a container // Accepts a map of the container's dependencies func (c *Container) generateSpec(ctx context.Context) (*spec.Spec, error) { overrides := c.getUserOverrides() execUser, err := lookup.GetUserGroupInfo(c.state.Mountpoint, c.config.User, overrides) if err != nil { return nil, err } g := generate.Generator{Config: c.config.Spec} // If network namespace was requested, add it now if c.config.CreateNetNS { if c.config.PostConfigureNetNS { if err := g.AddOrReplaceLinuxNamespace(string(spec.NetworkNamespace), ""); err != nil { return nil, err } } else { if err := g.AddOrReplaceLinuxNamespace(string(spec.NetworkNamespace), c.state.NetNS.Path()); err != nil { return nil, err } } } // Apply AppArmor checks and load the default profile if needed. if len(c.config.Spec.Process.ApparmorProfile) > 0 { updatedProfile, err := apparmor.CheckProfileAndLoadDefault(c.config.Spec.Process.ApparmorProfile) if err != nil { return nil, err } g.SetProcessApparmorProfile(updatedProfile) } if err := c.makeBindMounts(); err != nil { return nil, err } // Get host UID and GID based on the container process UID and GID. hostUID, hostGID, err := butil.GetHostIDs(util.IDtoolsToRuntimeSpec(c.config.IDMappings.UIDMap), util.IDtoolsToRuntimeSpec(c.config.IDMappings.GIDMap), uint32(execUser.Uid), uint32(execUser.Gid)) if err != nil { return nil, err } // Check if the spec file mounts contain the options z, Z or U. // If they have z or Z, relabel the source directory and then remove the option. // If they have U, chown the source directory and them remove the option. for i := range g.Config.Mounts { m := &g.Config.Mounts[i] var options []string for _, o := range m.Options { switch o { case "U": if m.Type == "tmpfs" { options = append(options, []string{fmt.Sprintf("uid=%d", execUser.Uid), fmt.Sprintf("gid=%d", execUser.Gid)}...) } else { if err := chown.ChangeHostPathOwnership(m.Source, true, int(hostUID), int(hostGID)); err != nil { return nil, err } } case "z": fallthrough case "Z": if err := label.Relabel(m.Source, c.MountLabel(), label.IsShared(o)); err != nil { return nil, err } default: options = append(options, o) } } m.Options = options } g.SetProcessSelinuxLabel(c.ProcessLabel()) g.SetLinuxMountLabel(c.MountLabel()) // Add named volumes for _, namedVol := range c.config.NamedVolumes { volume, err := c.runtime.GetVolume(namedVol.Name) if err != nil { return nil, errors.Wrapf(err, "error retrieving volume %s to add to container %s", namedVol.Name, c.ID()) } mountPoint, err := volume.MountPoint() if err != nil { return nil, err } volMount := spec.Mount{ Type: "bind", Source: mountPoint, Destination: namedVol.Dest, Options: namedVol.Options, } g.AddMount(volMount) } // Add bind mounts to container for dstPath, srcPath := range c.state.BindMounts { newMount := spec.Mount{ Type: "bind", Source: srcPath, Destination: dstPath, Options: []string{"bind", "rprivate"}, } if c.IsReadOnly() && dstPath != "/dev/shm" { newMount.Options = append(newMount.Options, "ro", "nosuid", "noexec", "nodev") } if !MountExists(g.Mounts(), dstPath) { g.AddMount(newMount) } else { logrus.Infof("User mount overriding libpod mount at %q", dstPath) } } // Add overlay volumes for _, overlayVol := range c.config.OverlayVolumes { contentDir, err := overlay.TempDir(c.config.StaticDir, c.RootUID(), c.RootGID()) if err != nil { return nil, err } overlayMount, err := overlay.Mount(contentDir, overlayVol.Source, overlayVol.Dest, c.RootUID(), c.RootGID(), c.runtime.store.GraphOptions()) if err != nil { return nil, errors.Wrapf(err, "mounting overlay failed %q", overlayVol.Source) } // Check overlay volume options for _, o := range overlayVol.Options { switch o { case "U": if err := chown.ChangeHostPathOwnership(overlayVol.Source, true, int(hostUID), int(hostGID)); err != nil { return nil, err } if err := chown.ChangeHostPathOwnership(contentDir, true, int(hostUID), int(hostGID)); err != nil { return nil, err } } } g.AddMount(overlayMount) } // Add image volumes as overlay mounts for _, volume := range c.config.ImageVolumes { // Mount the specified image. img, err := c.runtime.ImageRuntime().NewFromLocal(volume.Source) if err != nil { return nil, errors.Wrapf(err, "error creating image volume %q:%q", volume.Source, volume.Dest) } mountPoint, err := img.Mount(nil, "") if err != nil { return nil, errors.Wrapf(err, "error mounting image volume %q:%q", volume.Source, volume.Dest) } contentDir, err := overlay.TempDir(c.config.StaticDir, c.RootUID(), c.RootGID()) if err != nil { return nil, errors.Wrapf(err, "failed to create TempDir in the %s directory", c.config.StaticDir) } var overlayMount spec.Mount if volume.ReadWrite { overlayMount, err = overlay.Mount(contentDir, mountPoint, volume.Dest, c.RootUID(), c.RootGID(), c.runtime.store.GraphOptions()) } else { overlayMount, err = overlay.MountReadOnly(contentDir, mountPoint, volume.Dest, c.RootUID(), c.RootGID(), c.runtime.store.GraphOptions()) } if err != nil { return nil, errors.Wrapf(err, "creating overlay mount for image %q failed", volume.Source) } g.AddMount(overlayMount) } hasHomeSet := false for _, s := range c.config.Spec.Process.Env { if strings.HasPrefix(s, "HOME=") { hasHomeSet = true break } } if !hasHomeSet && execUser.Home != "" { c.config.Spec.Process.Env = append(c.config.Spec.Process.Env, fmt.Sprintf("HOME=%s", execUser.Home)) } if c.config.User != "" { // User and Group must go together g.SetProcessUID(uint32(execUser.Uid)) g.SetProcessGID(uint32(execUser.Gid)) } if c.config.Umask != "" { decVal, err := strconv.ParseUint(c.config.Umask, 8, 32) if err != nil { return nil, errors.Wrapf(err, "Invalid Umask Value") } umask := uint32(decVal) g.Config.Process.User.Umask = &umask } // Add addition groups if c.config.GroupAdd is not empty if len(c.config.Groups) > 0 { gids, err := lookup.GetContainerGroups(c.config.Groups, c.state.Mountpoint, overrides) if err != nil { return nil, errors.Wrapf(err, "error looking up supplemental groups for container %s", c.ID()) } for _, gid := range gids { g.AddProcessAdditionalGid(gid) } } if c.config.Systemd { if err := c.setupSystemd(g.Mounts(), g); err != nil { return nil, errors.Wrapf(err, "error adding systemd-specific mounts") } } // Look up and add groups the user belongs to, if a group wasn't directly specified if !strings.Contains(c.config.User, ":") { // the gidMappings that are present inside the container user namespace var gidMappings []idtools.IDMap switch { case len(c.config.IDMappings.GIDMap) > 0: gidMappings = c.config.IDMappings.GIDMap case rootless.IsRootless(): // Check whether the current user namespace has enough gids available. availableGids, err := rootless.GetAvailableGids() if err != nil { return nil, errors.Wrapf(err, "cannot read number of available GIDs") } gidMappings = []idtools.IDMap{{ ContainerID: 0, HostID: 0, Size: int(availableGids), }} default: gidMappings = []idtools.IDMap{{ ContainerID: 0, HostID: 0, Size: math.MaxInt32, }} } for _, gid := range execUser.Sgids { isGIDAvailable := false for _, m := range gidMappings { if gid >= m.ContainerID && gid < m.ContainerID+m.Size { isGIDAvailable = true break } } if isGIDAvailable { g.AddProcessAdditionalGid(uint32(gid)) } else { logrus.Warnf("additional gid=%d is not present in the user namespace, skip setting it", gid) } } } // Add shared namespaces from other containers if c.config.IPCNsCtr != "" { if err := c.addNamespaceContainer(&g, IPCNS, c.config.IPCNsCtr, spec.IPCNamespace); err != nil { return nil, err } } if c.config.MountNsCtr != "" { if err := c.addNamespaceContainer(&g, MountNS, c.config.MountNsCtr, spec.MountNamespace); err != nil { return nil, err } } if c.config.NetNsCtr != "" { if err := c.addNamespaceContainer(&g, NetNS, c.config.NetNsCtr, spec.NetworkNamespace); err != nil { return nil, err } } if c.config.PIDNsCtr != "" { if err := c.addNamespaceContainer(&g, PIDNS, c.config.PIDNsCtr, spec.PIDNamespace); err != nil { return nil, err } } if c.config.UserNsCtr != "" { if err := c.addNamespaceContainer(&g, UserNS, c.config.UserNsCtr, spec.UserNamespace); err != nil { return nil, err } if len(g.Config.Linux.UIDMappings) == 0 { // runc complains if no mapping is specified, even if we join another ns. So provide a dummy mapping g.AddLinuxUIDMapping(uint32(0), uint32(0), uint32(1)) g.AddLinuxGIDMapping(uint32(0), uint32(0), uint32(1)) } } availableUIDs, availableGIDs, err := rootless.GetAvailableIDMaps() if err != nil { return nil, err } g.Config.Linux.UIDMappings = rootless.MaybeSplitMappings(g.Config.Linux.UIDMappings, availableUIDs) g.Config.Linux.GIDMappings = rootless.MaybeSplitMappings(g.Config.Linux.GIDMappings, availableGIDs) // Hostname handling: // If we have a UTS namespace, set Hostname in the OCI spec. // Set the HOSTNAME environment variable unless explicitly overridden by // the user (already present in OCI spec). If we don't have a UTS ns, // set it to the host's hostname instead. hostname := c.Hostname() foundUTS := false for _, i := range c.config.Spec.Linux.Namespaces { if i.Type == spec.UTSNamespace && i.Path == "" { foundUTS = true g.SetHostname(hostname) break } } if !foundUTS { tmpHostname, err := os.Hostname() if err != nil { return nil, err } hostname = tmpHostname } needEnv := true for _, checkEnv := range g.Config.Process.Env { if strings.SplitN(checkEnv, "=", 2)[0] == "HOSTNAME" { needEnv = false break } } if needEnv { g.AddProcessEnv("HOSTNAME", hostname) } if c.config.UTSNsCtr != "" { if err := c.addNamespaceContainer(&g, UTSNS, c.config.UTSNsCtr, spec.UTSNamespace); err != nil { return nil, err } } if c.config.CgroupNsCtr != "" { if err := c.addNamespaceContainer(&g, CgroupNS, c.config.CgroupNsCtr, spec.CgroupNamespace); err != nil { return nil, err } } if c.config.IDMappings.AutoUserNs { if err := g.AddOrReplaceLinuxNamespace(string(spec.UserNamespace), ""); err != nil { return nil, err } g.ClearLinuxUIDMappings() for _, uidmap := range c.config.IDMappings.UIDMap { g.AddLinuxUIDMapping(uint32(uidmap.HostID), uint32(uidmap.ContainerID), uint32(uidmap.Size)) } g.ClearLinuxGIDMappings() for _, gidmap := range c.config.IDMappings.GIDMap { g.AddLinuxGIDMapping(uint32(gidmap.HostID), uint32(gidmap.ContainerID), uint32(gidmap.Size)) } } g.SetRootPath(c.state.Mountpoint) g.AddAnnotation(annotations.Created, c.config.CreatedTime.Format(time.RFC3339Nano)) g.AddAnnotation("org.opencontainers.image.stopSignal", fmt.Sprintf("%d", c.config.StopSignal)) if _, exists := g.Config.Annotations[annotations.ContainerManager]; !exists { g.AddAnnotation(annotations.ContainerManager, annotations.ContainerManagerLibpod) } // Only add container environment variable if not already present foundContainerEnv := false for _, env := range g.Config.Process.Env { if strings.HasPrefix(env, "container=") { foundContainerEnv = true break } } if !foundContainerEnv { g.AddProcessEnv("container", "libpod") } cgroupPath, err := c.getOCICgroupPath() if err != nil { return nil, err } g.SetLinuxCgroupsPath(cgroupPath) // Mounts need to be sorted so paths will not cover other paths mounts := sortMounts(g.Mounts()) g.ClearMounts() // Determine property of RootPropagation based on volume properties. If // a volume is shared, then keep root propagation shared. This should // work for slave and private volumes too. // // For slave volumes, it can be either [r]shared/[r]slave. // // For private volumes any root propagation value should work. rootPropagation := "" for _, m := range mounts { // We need to remove all symlinks from tmpfs mounts. // Runc and other runtimes may choke on them. // Easy solution: use securejoin to do a scoped evaluation of // the links, then trim off the mount prefix. if m.Type == "tmpfs" { finalPath, err := securejoin.SecureJoin(c.state.Mountpoint, m.Destination) if err != nil { return nil, errors.Wrapf(err, "error resolving symlinks for mount destination %s", m.Destination) } trimmedPath := strings.TrimPrefix(finalPath, strings.TrimSuffix(c.state.Mountpoint, "/")) m.Destination = trimmedPath } g.AddMount(m) for _, opt := range m.Options { switch opt { case MountShared, MountRShared: if rootPropagation != MountShared && rootPropagation != MountRShared { rootPropagation = MountShared } case MountSlave, MountRSlave: if rootPropagation != MountShared && rootPropagation != MountRShared && rootPropagation != MountSlave && rootPropagation != MountRSlave { rootPropagation = MountRSlave } } } } if rootPropagation != "" { logrus.Debugf("set root propagation to %q", rootPropagation) if err := g.SetLinuxRootPropagation(rootPropagation); err != nil { return nil, err } } // Warning: precreate hooks may alter g.Config in place. if c.state.ExtensionStageHooks, err = c.setupOCIHooks(ctx, g.Config); err != nil { return nil, errors.Wrapf(err, "error setting up OCI Hooks") } return g.Config, nil } // systemd expects to have /run, /run/lock and /tmp on tmpfs // It also expects to be able to write to /sys/fs/cgroup/systemd and /var/log/journal func (c *Container) setupSystemd(mounts []spec.Mount, g generate.Generator) error { options := []string{"rw", "rprivate", "nosuid", "nodev"} for _, dest := range []string{"/run", "/run/lock"} { if MountExists(mounts, dest) { continue } tmpfsMnt := spec.Mount{ Destination: dest, Type: "tmpfs", Source: "tmpfs", Options: append(options, "tmpcopyup"), } g.AddMount(tmpfsMnt) } for _, dest := range []string{"/tmp", "/var/log/journal"} { if MountExists(mounts, dest) { continue } tmpfsMnt := spec.Mount{ Destination: dest, Type: "tmpfs", Source: "tmpfs", Options: append(options, "tmpcopyup"), } g.AddMount(tmpfsMnt) } unified, err := cgroups.IsCgroup2UnifiedMode() if err != nil { return err } if unified { g.RemoveMount("/sys/fs/cgroup") hasCgroupNs := false for _, ns := range c.config.Spec.Linux.Namespaces { if ns.Type == spec.CgroupNamespace { hasCgroupNs = true break } } var systemdMnt spec.Mount if hasCgroupNs { systemdMnt = spec.Mount{ Destination: "/sys/fs/cgroup", Type: "cgroup", Source: "cgroup", Options: []string{"private", "rw"}, } } else { systemdMnt = spec.Mount{ Destination: "/sys/fs/cgroup", Type: "bind", Source: "/sys/fs/cgroup", Options: []string{"bind", "private", "rw"}, } } g.AddMount(systemdMnt) } else { mountOptions := []string{"bind", "rprivate"} var statfs unix.Statfs_t if err := unix.Statfs("/sys/fs/cgroup/systemd", &statfs); err != nil { mountOptions = append(mountOptions, "nodev", "noexec", "nosuid") } else { if statfs.Flags&unix.MS_NODEV == unix.MS_NODEV { mountOptions = append(mountOptions, "nodev") } if statfs.Flags&unix.MS_NOEXEC == unix.MS_NOEXEC { mountOptions = append(mountOptions, "noexec") } if statfs.Flags&unix.MS_NOSUID == unix.MS_NOSUID { mountOptions = append(mountOptions, "nosuid") } if statfs.Flags&unix.MS_RDONLY == unix.MS_RDONLY { mountOptions = append(mountOptions, "ro") } } systemdMnt := spec.Mount{ Destination: "/sys/fs/cgroup/systemd", Type: "bind", Source: "/sys/fs/cgroup/systemd", Options: mountOptions, } g.AddMount(systemdMnt) g.AddLinuxMaskedPaths("/sys/fs/cgroup/systemd/release_agent") } return nil } // Add an existing container's namespace to the spec func (c *Container) addNamespaceContainer(g *generate.Generator, ns LinuxNS, ctr string, specNS spec.LinuxNamespaceType) error { nsCtr, err := c.runtime.state.Container(ctr) if err != nil { return errors.Wrapf(err, "error retrieving dependency %s of container %s from state", ctr, c.ID()) } if specNS == spec.UTSNamespace { hostname := nsCtr.Hostname() // Joining an existing namespace, cannot set the hostname g.SetHostname("") g.AddProcessEnv("HOSTNAME", hostname) } // TODO need unlocked version of this for use in pods nsPath, err := nsCtr.NamespacePath(ns) if err != nil { return err } if err := g.AddOrReplaceLinuxNamespace(string(specNS), nsPath); err != nil { return err } return nil } func (c *Container) exportCheckpoint(options ContainerCheckpointOptions) error { if len(c.Dependencies()) > 0 { return errors.Errorf("Cannot export checkpoints of containers with dependencies") } logrus.Debugf("Exporting checkpoint image of container %q to %q", c.ID(), options.TargetFile) includeFiles := []string{ "artifacts", "ctr.log", metadata.CheckpointDirectory, metadata.ConfigDumpFile, metadata.SpecDumpFile, metadata.NetworkStatusFile, } if options.PreCheckPoint { includeFiles[0] = "pre-checkpoint" } // Get root file-system changes included in the checkpoint archive var addToTarFiles []string if !options.IgnoreRootfs { // To correctly track deleted files, let's go through the output of 'podman diff' rootFsChanges, err := c.runtime.GetDiff("", c.ID()) if err != nil { return errors.Wrapf(err, "error exporting root file-system diff for %q", c.ID()) } addToTarFiles, err := crutils.CRCreateRootFsDiffTar(&rootFsChanges, c.state.Mountpoint, c.bundlePath()) if err != nil { return err } includeFiles = append(includeFiles, addToTarFiles...) } // Folder containing archived volumes that will be included in the export expVolDir := filepath.Join(c.bundlePath(), "volumes") // Create an archive for each volume associated with the container if !options.IgnoreVolumes { if err := os.MkdirAll(expVolDir, 0700); err != nil { return errors.Wrapf(err, "error creating volumes export directory %q", expVolDir) } for _, v := range c.config.NamedVolumes { volumeTarFilePath := filepath.Join("volumes", v.Name+".tar") volumeTarFileFullPath := filepath.Join(c.bundlePath(), volumeTarFilePath) volumeTarFile, err := os.Create(volumeTarFileFullPath) if err != nil { return errors.Wrapf(err, "error creating %q", volumeTarFileFullPath) } volume, err := c.runtime.GetVolume(v.Name) if err != nil { return err } mp, err := volume.MountPoint() if err != nil { return err } if mp == "" { return errors.Wrapf(define.ErrInternal, "volume %s is not mounted, cannot export", volume.Name()) } input, err := archive.TarWithOptions(mp, &archive.TarOptions{ Compression: archive.Uncompressed, IncludeSourceDir: true, }) if err != nil { return errors.Wrapf(err, "error reading volume directory %q", v.Dest) } _, err = io.Copy(volumeTarFile, input) if err != nil { return err } volumeTarFile.Close() includeFiles = append(includeFiles, volumeTarFilePath) } } input, err := archive.TarWithOptions(c.bundlePath(), &archive.TarOptions{ Compression: archive.Gzip, IncludeSourceDir: true, IncludeFiles: includeFiles, }) if err != nil { return errors.Wrapf(err, "error reading checkpoint directory %q", c.ID()) } outFile, err := os.Create(options.TargetFile) if err != nil { return errors.Wrapf(err, "error creating checkpoint export file %q", options.TargetFile) } defer outFile.Close() if err := os.Chmod(options.TargetFile, 0600); err != nil { return err } _, err = io.Copy(outFile, input) if err != nil { return err } for _, file := range addToTarFiles { os.Remove(filepath.Join(c.bundlePath(), file)) } if !options.IgnoreVolumes { os.RemoveAll(expVolDir) } return nil } func (c *Container) checkpointRestoreSupported() error { if !criu.CheckForCriu() { return errors.Errorf("checkpoint/restore requires at least CRIU %d", criu.MinCriuVersion) } if !c.ociRuntime.SupportsCheckpoint() { return errors.Errorf("configured runtime does not support checkpoint/restore") } return nil } func (c *Container) checkpoint(ctx context.Context, options ContainerCheckpointOptions) error { if err := c.checkpointRestoreSupported(); err != nil { return err } if c.state.State != define.ContainerStateRunning { return errors.Wrapf(define.ErrCtrStateInvalid, "%q is not running, cannot checkpoint", c.state.State) } if c.AutoRemove() && options.TargetFile == "" { return errors.Errorf("cannot checkpoint containers that have been started with '--rm' unless '--export' is used") } if err := crutils.CRCreateFileWithLabel(c.bundlePath(), "dump.log", c.MountLabel()); err != nil { return err } if err := c.ociRuntime.CheckpointContainer(c, options); err != nil { return err } // Save network.status. This is needed to restore the container with // the same IP. Currently limited to one IP address in a container // with one interface. if _, err := metadata.WriteJSONFile(c.state.NetworkStatus, c.bundlePath(), metadata.NetworkStatusFile); err != nil { return err } defer c.newContainerEvent(events.Checkpoint) // There is a bug from criu: https://github.com/checkpoint-restore/criu/issues/116 // We have to change the symbolic link from absolute path to relative path if options.WithPrevious { os.Remove(path.Join(c.CheckpointPath(), "parent")) if err := os.Symlink("../pre-checkpoint", path.Join(c.CheckpointPath(), "parent")); err != nil { return err } } if options.TargetFile != "" { if err := c.exportCheckpoint(options); err != nil { return err } } logrus.Debugf("Checkpointed container %s", c.ID()) if !options.KeepRunning && !options.PreCheckPoint { c.state.State = define.ContainerStateStopped // Cleanup Storage and Network if err := c.cleanup(ctx); err != nil { return err } } if !options.Keep && !options.PreCheckPoint { cleanup := []string{ "dump.log", "stats-dump", metadata.ConfigDumpFile, metadata.SpecDumpFile, } for _, del := range cleanup { file := filepath.Join(c.bundlePath(), del) if err := os.Remove(file); err != nil { logrus.Debugf("unable to remove file %s", file) } } } c.state.FinishedTime = time.Now() return c.save() } func (c *Container) importCheckpoint(input string) error { if err := crutils.CRImportCheckpointWithoutConfig(c.bundlePath(), input); err != nil { return err } // Make sure the newly created config.json exists on disk g := generate.Generator{Config: c.config.Spec} if err := c.saveSpec(g.Config); err != nil { return errors.Wrap(err, "saving imported container specification for restore failed") } return nil } func (c *Container) importPreCheckpoint(input string) error { archiveFile, err := os.Open(input) if err != nil { return errors.Wrap(err, "failed to open pre-checkpoint archive for import") } defer archiveFile.Close() err = archive.Untar(archiveFile, c.bundlePath(), nil) if err != nil { return errors.Wrapf(err, "Unpacking of pre-checkpoint archive %s failed", input) } return nil } func (c *Container) restore(ctx context.Context, options ContainerCheckpointOptions) (retErr error) { if err := c.checkpointRestoreSupported(); err != nil { return err } if !c.ensureState(define.ContainerStateConfigured, define.ContainerStateExited) { return errors.Wrapf(define.ErrCtrStateInvalid, "container %s is running or paused, cannot restore", c.ID()) } if options.ImportPrevious != "" { if err := c.importPreCheckpoint(options.ImportPrevious); err != nil { return err } } if options.TargetFile != "" { if err := c.importCheckpoint(options.TargetFile); err != nil { return err } } // Let's try to stat() CRIU's inventory file. If it does not exist, it makes // no sense to try a restore. This is a minimal check if a checkpoint exist. if _, err := os.Stat(filepath.Join(c.CheckpointPath(), "inventory.img")); os.IsNotExist(err) { return errors.Wrapf(err, "a complete checkpoint for this container cannot be found, cannot restore") } if err := crutils.CRCreateFileWithLabel(c.bundlePath(), "restore.log", c.MountLabel()); err != nil { return err } // If a container is restored multiple times from an exported checkpoint with // the help of '--import --name', the restore will fail if during 'podman run' // a static container IP was set with '--ip'. The user can tell the restore // process to ignore the static IP with '--ignore-static-ip' if options.IgnoreStaticIP { c.config.StaticIP = nil } // If a container is restored multiple times from an exported checkpoint with // the help of '--import --name', the restore will fail if during 'podman run' // a static container MAC address was set with '--mac-address'. The user // can tell the restore process to ignore the static MAC with // '--ignore-static-mac' if options.IgnoreStaticMAC { c.config.StaticMAC = nil } // Read network configuration from checkpoint // Currently only one interface with one IP is supported. networkStatus, _, err := metadata.ReadContainerCheckpointNetworkStatus(c.bundlePath()) // If the restored container should get a new name, the IP address of // the container will not be restored. This assumes that if a new name is // specified, the container is restored multiple times. // TODO: This implicit restoring with or without IP depending on an // unrelated restore parameter (--name) does not seem like the // best solution. if err == nil && options.Name == "" && (!options.IgnoreStaticIP || !options.IgnoreStaticMAC) { // The file with the network.status does exist. Let's restore the // container with the same IP address / MAC address as during checkpointing. if !options.IgnoreStaticIP { if IP := metadata.GetIPFromNetworkStatus(networkStatus); IP != nil { // Tell CNI which IP address we want. c.requestedIP = IP } } if !options.IgnoreStaticMAC { if MAC := metadata.GetMACFromNetworkStatus(networkStatus); MAC != nil { // Tell CNI which MAC address we want. c.requestedMAC = MAC } } } defer func() { if retErr != nil { if err := c.cleanup(ctx); err != nil { logrus.Errorf("error cleaning up container %s: %v", c.ID(), err) } } }() if err := c.prepare(); err != nil { return err } // Read config jsonPath := filepath.Join(c.bundlePath(), "config.json") logrus.Debugf("generate.NewFromFile at %v", jsonPath) g, err := generate.NewFromFile(jsonPath) if err != nil { logrus.Debugf("generate.NewFromFile failed with %v", err) return err } // Restoring from an import means that we are doing migration if options.TargetFile != "" { g.SetRootPath(c.state.Mountpoint) } // We want to have the same network namespace as before. if c.config.CreateNetNS { netNSPath := "" if !c.config.PostConfigureNetNS { netNSPath = c.state.NetNS.Path() } if err := g.AddOrReplaceLinuxNamespace(string(spec.NetworkNamespace), netNSPath); err != nil { return err } } if err := c.makeBindMounts(); err != nil { return err } if options.TargetFile != "" { for dstPath, srcPath := range c.state.BindMounts { newMount := spec.Mount{ Type: "bind", Source: srcPath, Destination: dstPath, Options: []string{"bind", "private"}, } if c.IsReadOnly() && dstPath != "/dev/shm" { newMount.Options = append(newMount.Options, "ro", "nosuid", "noexec", "nodev") } if !MountExists(g.Mounts(), dstPath) { g.AddMount(newMount) } } } // Cleanup for a working restore. if err := c.removeConmonFiles(); err != nil { return err } // Save the OCI spec to disk if err := c.saveSpec(g.Config); err != nil { return err } // When restoring from an imported archive, allow restoring the content of volumes. // Volumes are created in setupContainer() if options.TargetFile != "" && !options.IgnoreVolumes { for _, v := range c.config.NamedVolumes { volumeFilePath := filepath.Join(c.bundlePath(), "volumes", v.Name+".tar") volumeFile, err := os.Open(volumeFilePath) if err != nil { return errors.Wrapf(err, "failed to open volume file %s", volumeFilePath) } defer volumeFile.Close() volume, err := c.runtime.GetVolume(v.Name) if err != nil { return errors.Wrapf(err, "failed to retrieve volume %s", v.Name) } mountPoint, err := volume.MountPoint() if err != nil { return err } if mountPoint == "" { return errors.Wrapf(err, "unable to import volume %s as it is not mounted", volume.Name()) } if err := archive.UntarUncompressed(volumeFile, mountPoint, nil); err != nil { return errors.Wrapf(err, "Failed to extract volume %s to %s", volumeFilePath, mountPoint) } } } // Before actually restarting the container, apply the root file-system changes if !options.IgnoreRootfs { if err := crutils.CRApplyRootFsDiffTar(c.bundlePath(), c.state.Mountpoint); err != nil { return err } if err := crutils.CRRemoveDeletedFiles(c.ID(), c.bundlePath(), c.state.Mountpoint); err != nil { return err } } if err := c.ociRuntime.CreateContainer(c, &options); err != nil { return err } logrus.Debugf("Restored container %s", c.ID()) c.state.State = define.ContainerStateRunning if !options.Keep { // Delete all checkpoint related files. At this point, in theory, all files // should exist. Still ignoring errors for now as the container should be // restored and running. Not erroring out just because some cleanup operation // failed. Starting with the checkpoint directory err = os.RemoveAll(c.CheckpointPath()) if err != nil { logrus.Debugf("Non-fatal: removal of checkpoint directory (%s) failed: %v", c.CheckpointPath(), err) } err = os.RemoveAll(c.PreCheckPointPath()) if err != nil { logrus.Debugf("Non-fatal: removal of pre-checkpoint directory (%s) failed: %v", c.PreCheckPointPath(), err) } cleanup := [...]string{ "restore.log", "dump.log", "stats-dump", "stats-restore", metadata.NetworkStatusFile, metadata.RootFsDiffTar, metadata.DeletedFilesFile, } for _, del := range cleanup { file := filepath.Join(c.bundlePath(), del) err = os.Remove(file) if err != nil { logrus.Debugf("Non-fatal: removal of checkpoint file (%s) failed: %v", file, err) } } } return c.save() } // Make standard bind mounts to include in the container func (c *Container) makeBindMounts() error { if err := os.Chown(c.state.RunDir, c.RootUID(), c.RootGID()); err != nil { return errors.Wrap(err, "cannot chown run directory") } if c.state.BindMounts == nil { c.state.BindMounts = make(map[string]string) } netDisabled, err := c.NetworkDisabled() if err != nil { return err } if !netDisabled { // If /etc/resolv.conf and /etc/hosts exist, delete them so we // will recreate. Only do this if we aren't sharing them with // another container. if c.config.NetNsCtr == "" { if resolvePath, ok := c.state.BindMounts["/etc/resolv.conf"]; ok { if err := os.Remove(resolvePath); err != nil && !os.IsNotExist(err) { return errors.Wrapf(err, "container %s", c.ID()) } delete(c.state.BindMounts, "/etc/resolv.conf") } if hostsPath, ok := c.state.BindMounts["/etc/hosts"]; ok { if err := os.Remove(hostsPath); err != nil && !os.IsNotExist(err) { return errors.Wrapf(err, "container %s", c.ID()) } delete(c.state.BindMounts, "/etc/hosts") } } if c.config.NetNsCtr != "" && (!c.config.UseImageResolvConf || !c.config.UseImageHosts) { // We share a net namespace. // We want /etc/resolv.conf and /etc/hosts from the // other container. Unless we're not creating both of // them. var ( depCtr *Container nextCtr string ) // I don't like infinite loops, but I don't think there's // a serious risk of looping dependencies - too many // protections against that elsewhere. nextCtr = c.config.NetNsCtr for { depCtr, err = c.runtime.state.Container(nextCtr) if err != nil { return errors.Wrapf(err, "error fetching dependency %s of container %s", c.config.NetNsCtr, c.ID()) } nextCtr = depCtr.config.NetNsCtr if nextCtr == "" { break } } // We need that container's bind mounts bindMounts, err := depCtr.BindMounts() if err != nil { return errors.Wrapf(err, "error fetching bind mounts from dependency %s of container %s", depCtr.ID(), c.ID()) } // The other container may not have a resolv.conf or /etc/hosts // If it doesn't, don't copy them resolvPath, exists := bindMounts["/etc/resolv.conf"] if !c.config.UseImageResolvConf && exists { c.state.BindMounts["/etc/resolv.conf"] = resolvPath } // check if dependency container has an /etc/hosts file. // It may not have one, so only use it if it does. hostsPath, exists := bindMounts["/etc/hosts"] if !c.config.UseImageHosts && exists { depCtr.lock.Lock() // generate a hosts file for the dependency container, // based on either its old hosts file, or the default, // and add the relevant information from the new container (hosts and IP) hostsPath, err = depCtr.appendHosts(hostsPath, c) if err != nil { depCtr.lock.Unlock() return errors.Wrapf(err, "error creating hosts file for container %s which depends on container %s", c.ID(), depCtr.ID()) } depCtr.lock.Unlock() // finally, save it in the new container c.state.BindMounts["/etc/hosts"] = hostsPath } if !hasCurrentUserMapped(c) { if err := makeAccessible(resolvPath, c.RootUID(), c.RootGID()); err != nil { return err } if err := makeAccessible(hostsPath, c.RootUID(), c.RootGID()); err != nil { return err } } } else { if !c.config.UseImageResolvConf { newResolv, err := c.generateResolvConf() if err != nil { return errors.Wrapf(err, "error creating resolv.conf for container %s", c.ID()) } c.state.BindMounts["/etc/resolv.conf"] = newResolv } if !c.config.UseImageHosts { newHosts, err := c.generateHosts("/etc/hosts") if err != nil { return errors.Wrapf(err, "error creating hosts file for container %s", c.ID()) } c.state.BindMounts["/etc/hosts"] = newHosts } } if c.state.BindMounts["/etc/hosts"] != "" { if err := label.Relabel(c.state.BindMounts["/etc/hosts"], c.config.MountLabel, true); err != nil { return err } } if c.state.BindMounts["/etc/resolv.conf"] != "" { if err := label.Relabel(c.state.BindMounts["/etc/resolv.conf"], c.config.MountLabel, true); err != nil { return err } } } else { if !c.config.UseImageHosts && c.state.BindMounts["/etc/hosts"] == "" { newHosts, err := c.generateHosts("/etc/hosts") if err != nil { return errors.Wrapf(err, "error creating hosts file for container %s", c.ID()) } c.state.BindMounts["/etc/hosts"] = newHosts } } // SHM is always added when we mount the container c.state.BindMounts["/dev/shm"] = c.config.ShmDir newPasswd, newGroup, err := c.generatePasswdAndGroup() if err != nil { return errors.Wrapf(err, "error creating temporary passwd file for container %s", c.ID()) } if newPasswd != "" { // Make /etc/passwd // If it already exists, delete so we can recreate delete(c.state.BindMounts, "/etc/passwd") c.state.BindMounts["/etc/passwd"] = newPasswd } if newGroup != "" { // Make /etc/group // If it already exists, delete so we can recreate delete(c.state.BindMounts, "/etc/group") c.state.BindMounts["/etc/group"] = newGroup } // Make /etc/hostname // This should never change, so no need to recreate if it exists if _, ok := c.state.BindMounts["/etc/hostname"]; !ok { hostnamePath, err := c.writeStringToRundir("hostname", c.Hostname()) if err != nil { return errors.Wrapf(err, "error creating hostname file for container %s", c.ID()) } c.state.BindMounts["/etc/hostname"] = hostnamePath } // Make /etc/localtime if c.Timezone() != "" { if _, ok := c.state.BindMounts["/etc/localtime"]; !ok { var zonePath string if c.Timezone() == "local" { zonePath, err = filepath.EvalSymlinks("/etc/localtime") if err != nil { return errors.Wrapf(err, "error finding local timezone for container %s", c.ID()) } } else { zone := filepath.Join("/usr/share/zoneinfo", c.Timezone()) zonePath, err = filepath.EvalSymlinks(zone) if err != nil { return errors.Wrapf(err, "error setting timezone for container %s", c.ID()) } } localtimePath, err := c.copyTimezoneFile(zonePath) if err != nil { return errors.Wrapf(err, "error setting timezone for container %s", c.ID()) } c.state.BindMounts["/etc/localtime"] = localtimePath } } // Make .containerenv if it does not exist if _, ok := c.state.BindMounts["/run/.containerenv"]; !ok { containerenv := c.runtime.graphRootMountedFlag(c.config.Spec.Mounts) isRootless := 0 if rootless.IsRootless() { isRootless = 1 } imageID, imageName := c.Image() if c.Privileged() { // Populate the .containerenv with container information containerenv = fmt.Sprintf(`engine="podman-%s" name=%q id=%q image=%q imageid=%q rootless=%d %s`, version.Version.String(), c.Name(), c.ID(), imageName, imageID, isRootless, containerenv) } containerenvPath, err := c.writeStringToRundir(".containerenv", containerenv) if err != nil { return errors.Wrapf(err, "error creating containerenv file for container %s", c.ID()) } c.state.BindMounts["/run/.containerenv"] = containerenvPath } // Add Subscription Mounts subscriptionMounts := subscriptions.MountsWithUIDGID(c.config.MountLabel, c.state.RunDir, c.runtime.config.Containers.DefaultMountsFile, c.state.Mountpoint, c.RootUID(), c.RootGID(), rootless.IsRootless(), false) for _, mount := range subscriptionMounts { if _, ok := c.state.BindMounts[mount.Destination]; !ok { c.state.BindMounts[mount.Destination] = mount.Source } } // Secrets are mounted by getting the secret data from the secrets manager, // copying the data into the container's static dir, // then mounting the copied dir into /run/secrets. // The secrets mounting must come after subscription mounts, since subscription mounts // creates the /run/secrets dir in the container where we mount as well. if len(c.Secrets()) > 0 { // create /run/secrets if subscriptions did not create if err := c.createSecretMountDir(); err != nil { return errors.Wrapf(err, "error creating secrets mount") } for _, secret := range c.Secrets() { src := filepath.Join(c.config.SecretsPath, secret.Name) dest := filepath.Join("/run/secrets", secret.Name) c.state.BindMounts[dest] = src } } return nil } // generateResolvConf generates a containers resolv.conf func (c *Container) generateResolvConf() (string, error) { var ( nameservers []string cniNameServers []string cniSearchDomains []string ) resolvConf := "/etc/resolv.conf" for _, namespace := range c.config.Spec.Linux.Namespaces { if namespace.Type == spec.NetworkNamespace { if namespace.Path != "" && !strings.HasPrefix(namespace.Path, "/proc/") { definedPath := filepath.Join("/etc/netns", filepath.Base(namespace.Path), "resolv.conf") _, err := os.Stat(definedPath) if err == nil { resolvConf = definedPath } else if !os.IsNotExist(err) { return "", err } } break } } // Determine the endpoint for resolv.conf in case it is a symlink resolvPath, err := filepath.EvalSymlinks(resolvConf) // resolv.conf doesn't have to exists if err != nil && !os.IsNotExist(err) { return "", err } // Determine if symlink points to any of the systemd-resolved files if strings.HasPrefix(resolvPath, "/run/systemd/resolve/") { resolvPath = "/run/systemd/resolve/resolv.conf" } contents, err := ioutil.ReadFile(resolvPath) // resolv.conf doesn't have to exists if err != nil && !os.IsNotExist(err) { return "", err } // Ensure that the container's /etc/resolv.conf is compatible with its // network configuration. // TODO: set ipv6 enable bool more sanely resolv, err := resolvconf.FilterResolvDNS(contents, true, c.config.CreateNetNS) if err != nil { return "", errors.Wrapf(err, "error parsing host resolv.conf") } // Check if CNI gave back and DNS servers for us to add in cniResponse := c.state.NetworkStatus for _, i := range cniResponse { if i.DNS.Nameservers != nil { cniNameServers = append(cniNameServers, i.DNS.Nameservers...) logrus.Debugf("adding nameserver(s) from cni response of '%q'", i.DNS.Nameservers) } if i.DNS.Search != nil { cniSearchDomains = append(cniSearchDomains, i.DNS.Search...) logrus.Debugf("adding search domain(s) from cni response of '%q'", i.DNS.Search) } } dns := make([]net.IP, 0, len(c.runtime.config.Containers.DNSServers)) for _, i := range c.runtime.config.Containers.DNSServers { result := net.ParseIP(i) if result == nil { return "", errors.Wrapf(define.ErrInvalidArg, "invalid IP address %s", i) } dns = append(dns, result) } dnsServers := append(dns, c.config.DNSServer...) // If the user provided dns, it trumps all; then dns masq; then resolv.conf switch { case len(dnsServers) > 0: // We store DNS servers as net.IP, so need to convert to string for _, server := range dnsServers { nameservers = append(nameservers, server.String()) } case len(cniNameServers) > 0: nameservers = append(nameservers, cniNameServers...) default: // Make a new resolv.conf nameservers = resolvconf.GetNameservers(resolv.Content) // slirp4netns has a built in DNS server. if c.config.NetMode.IsSlirp4netns() { nameservers = append([]string{slirp4netnsDNS}, nameservers...) } } var search []string if len(c.config.DNSSearch) > 0 || len(c.runtime.config.Containers.DNSSearches) > 0 || len(cniSearchDomains) > 0 { if !util.StringInSlice(".", c.config.DNSSearch) { search = c.runtime.config.Containers.DNSSearches search = append(search, c.config.DNSSearch...) search = append(search, cniSearchDomains...) } } else { search = resolvconf.GetSearchDomains(resolv.Content) } var options []string if len(c.config.DNSOption) > 0 || len(c.runtime.config.Containers.DNSOptions) > 0 { options = c.runtime.config.Containers.DNSOptions options = append(options, c.config.DNSOption...) } else { options = resolvconf.GetOptions(resolv.Content) } destPath := filepath.Join(c.state.RunDir, "resolv.conf") if err := os.Remove(destPath); err != nil && !os.IsNotExist(err) { return "", errors.Wrapf(err, "container %s", c.ID()) } // Build resolv.conf if _, err = resolvconf.Build(destPath, nameservers, search, options); err != nil { return "", errors.Wrapf(err, "error building resolv.conf for container %s", c.ID()) } // Relabel resolv.conf for the container if err := label.Relabel(destPath, c.config.MountLabel, true); err != nil { return "", err } return filepath.Join(c.state.RunDir, "resolv.conf"), nil } // generateHosts creates a containers hosts file func (c *Container) generateHosts(path string) (string, error) { orig, err := ioutil.ReadFile(path) if err != nil { return "", err } hosts := string(orig) hosts += c.getHosts() return c.writeStringToRundir("hosts", hosts) } // appendHosts appends a container's config and state pertaining to hosts to a container's // local hosts file. netCtr is the container from which the netNS information is // taken. // path is the basis of the hosts file, into which netCtr's netNS information will be appended. // FIXME. Path should be used by this function,but I am not sure what is correct; remove //lint // once this is fixed func (c *Container) appendHosts(path string, netCtr *Container) (string, error) { //nolint return c.appendStringToRunDir("hosts", netCtr.getHosts()) } // getHosts finds the pertinent information for a container's host file in its config and state // and returns a string in a format that can be written to the host file func (c *Container) getHosts() string { var hosts string if len(c.config.HostAdd) > 0 { for _, host := range c.config.HostAdd { // the host format has already been verified at this point fields := strings.SplitN(host, ":", 2) hosts += fmt.Sprintf("%s %s\n", fields[1], fields[0]) } } hosts += c.cniHosts() // If not making a network namespace, add our own hostname. if c.Hostname() != "" { if c.config.NetMode.IsSlirp4netns() { // When using slirp4netns, the interface gets a static IP hosts += fmt.Sprintf("# used by slirp4netns\n%s\t%s %s\n", slirp4netnsIP, c.Hostname(), c.config.Name) } else { hasNetNS := false netNone := false for _, ns := range c.config.Spec.Linux.Namespaces { if ns.Type == spec.NetworkNamespace { hasNetNS = true if ns.Path == "" && !c.config.CreateNetNS { netNone = true } break } } if !hasNetNS { // 127.0.1.1 and host's hostname to match Docker osHostname, _ := os.Hostname() hosts += fmt.Sprintf("127.0.1.1 %s %s %s\n", osHostname, c.Hostname(), c.config.Name) } if netNone { hosts += fmt.Sprintf("127.0.1.1 %s %s\n", c.Hostname(), c.config.Name) } } } return hosts } // generateGroupEntry generates an entry or entries into /etc/group as // required by container configuration. // Generally speaking, we will make an entry under two circumstances: // 1. The container is started as a specific user:group, and that group is both // numeric, and does not already exist in /etc/group. // 2. It is requested that Libpod add the group that launched Podman to // /etc/group via AddCurrentUserPasswdEntry (though this does not trigger if // the group in question already exists in /etc/passwd). // Returns group entry (as a string that can be appended to /etc/group) and any // error that occurred. func (c *Container) generateGroupEntry() (string, error) { groupString := "" // Things we *can't* handle: adding the user we added in // generatePasswdEntry to any *existing* groups. addedGID := 0 if c.config.AddCurrentUserPasswdEntry { entry, gid, err := c.generateCurrentUserGroupEntry() if err != nil { return "", err } groupString += entry addedGID = gid } if c.config.User != "" { entry, _, err := c.generateUserGroupEntry(addedGID) if err != nil { return "", err } groupString += entry } return groupString, nil } // Make an entry in /etc/group for the group of the user running podman iff we // are rootless. func (c *Container) generateCurrentUserGroupEntry() (string, int, error) { gid := rootless.GetRootlessGID() if gid == 0 { return "", 0, nil } g, err := user.LookupGroupId(strconv.Itoa(gid)) if err != nil { return "", 0, errors.Wrapf(err, "failed to get current group") } // Lookup group name to see if it exists in the image. _, err = lookup.GetGroup(c.state.Mountpoint, g.Name) if err != runcuser.ErrNoGroupEntries { return "", 0, err } // Lookup GID to see if it exists in the image. _, err = lookup.GetGroup(c.state.Mountpoint, g.Gid) if err != runcuser.ErrNoGroupEntries { return "", 0, err } // We need to get the username of the rootless user so we can add it to // the group. username := "" uid := rootless.GetRootlessUID() if uid != 0 { u, err := user.LookupId(strconv.Itoa(uid)) if err != nil { return "", 0, errors.Wrapf(err, "failed to get current user to make group entry") } username = u.Username } // Make the entry. return fmt.Sprintf("%s:x:%s:%s\n", g.Name, g.Gid, username), gid, nil } // Make an entry in /etc/group for the group the container was specified to run // as. func (c *Container) generateUserGroupEntry(addedGID int) (string, int, error) { if c.config.User == "" { return "", 0, nil } splitUser := strings.SplitN(c.config.User, ":", 2) group := splitUser[0] if len(splitUser) > 1 { group = splitUser[1] } gid, err := strconv.ParseUint(group, 10, 32) if err != nil { return "", 0, nil } if addedGID != 0 && addedGID == int(gid) { return "", 0, nil } // Check if the group already exists _, err = lookup.GetGroup(c.state.Mountpoint, group) if err != runcuser.ErrNoGroupEntries { return "", 0, err } return fmt.Sprintf("%d:x:%d:%s\n", gid, gid, splitUser[0]), int(gid), nil } // generatePasswdEntry generates an entry or entries into /etc/passwd as // required by container configuration. // Generally speaking, we will make an entry under two circumstances: // 1. The container is started as a specific user who is not in /etc/passwd. // This only triggers if the user is given as a *numeric* ID. // 2. It is requested that Libpod add the user that launched Podman to // /etc/passwd via AddCurrentUserPasswdEntry (though this does not trigger if // the user in question already exists in /etc/passwd) or the UID to be added // is 0). // Returns password entry (as a string that can be appended to /etc/passwd) and // any error that occurred. func (c *Container) generatePasswdEntry() (string, error) { passwdString := "" addedUID := 0 if c.config.AddCurrentUserPasswdEntry { entry, uid, _, err := c.generateCurrentUserPasswdEntry() if err != nil { return "", err } passwdString += entry addedUID = uid } if c.config.User != "" { entry, _, _, err := c.generateUserPasswdEntry(addedUID) if err != nil { return "", err } passwdString += entry } return passwdString, nil } // generateCurrentUserPasswdEntry generates an /etc/passwd entry for the user // running the container engine. // Returns a passwd entry for the user, and the UID and GID of the added entry. func (c *Container) generateCurrentUserPasswdEntry() (string, int, int, error) { uid := rootless.GetRootlessUID() if uid == 0 { return "", 0, 0, nil } u, err := user.LookupId(strconv.Itoa(uid)) if err != nil { return "", 0, 0, errors.Wrapf(err, "failed to get current user") } // Lookup the user to see if it exists in the container image. _, err = lookup.GetUser(c.state.Mountpoint, u.Username) if err != runcuser.ErrNoPasswdEntries { return "", 0, 0, err } // Lookup the UID to see if it exists in the container image. _, err = lookup.GetUser(c.state.Mountpoint, u.Uid) if err != runcuser.ErrNoPasswdEntries { return "", 0, 0, err } // If the user's actual home directory exists, or was mounted in - use // that. homeDir := c.WorkingDir() hDir := u.HomeDir for hDir != "/" { if MountExists(c.config.Spec.Mounts, hDir) { homeDir = u.HomeDir break } hDir = filepath.Dir(hDir) } if homeDir != u.HomeDir { for _, hDir := range c.UserVolumes() { if hDir == u.HomeDir { homeDir = u.HomeDir break } } } // Set HOME environment if not already set hasHomeSet := false for _, s := range c.config.Spec.Process.Env { if strings.HasPrefix(s, "HOME=") { hasHomeSet = true break } } if !hasHomeSet { c.config.Spec.Process.Env = append(c.config.Spec.Process.Env, fmt.Sprintf("HOME=%s", homeDir)) } return fmt.Sprintf("%s:*:%s:%s:%s:%s:/bin/sh\n", u.Username, u.Uid, u.Gid, u.Name, homeDir), uid, rootless.GetRootlessGID(), nil } // generateUserPasswdEntry generates an /etc/passwd entry for the container user // to run in the container. // The UID and GID of the added entry will also be returned. // Accepts one argument, that being any UID that has already been added to the // passwd file by other functions; if it matches the UID we were given, we don't // need to do anything. func (c *Container) generateUserPasswdEntry(addedUID int) (string, int, int, error) { var ( groupspec string gid int ) if c.config.User == "" { return "", 0, 0, nil } splitSpec := strings.SplitN(c.config.User, ":", 2) userspec := splitSpec[0] if len(splitSpec) > 1 { groupspec = splitSpec[1] } // If a non numeric User, then don't generate passwd uid, err := strconv.ParseUint(userspec, 10, 32) if err != nil { return "", 0, 0, nil } if addedUID != 0 && int(uid) == addedUID { return "", 0, 0, nil } // Lookup the user to see if it exists in the container image _, err = lookup.GetUser(c.state.Mountpoint, userspec) if err != runcuser.ErrNoPasswdEntries { return "", 0, 0, err } if groupspec != "" { ugid, err := strconv.ParseUint(groupspec, 10, 32) if err == nil { gid = int(ugid) } else { group, err := lookup.GetGroup(c.state.Mountpoint, groupspec) if err != nil { return "", 0, 0, errors.Wrapf(err, "unable to get gid %s from group file", groupspec) } gid = group.Gid } } return fmt.Sprintf("%d:*:%d:%d:container user:%s:/bin/sh\n", uid, uid, gid, c.WorkingDir()), int(uid), gid, nil } // generatePasswdAndGroup generates container-specific passwd and group files // iff g.config.User is a number or we are configured to make a passwd entry for // the current user. // Returns path to file to mount at /etc/passwd, path to file to mount at // /etc/group, and any error that occurred. If no passwd/group file were // required, the empty string will be returned for those path (this may occur // even if no error happened). // This may modify the mounted container's /etc/passwd and /etc/group instead of // making copies to bind-mount in, so we don't break useradd (it wants to make a // copy of /etc/passwd and rename the copy to /etc/passwd, which is impossible // with a bind mount). This is done in cases where the container is *not* // read-only. In this case, the function will return nothing ("", "", nil). func (c *Container) generatePasswdAndGroup() (string, string, error) { if !c.config.AddCurrentUserPasswdEntry && c.config.User == "" { return "", "", nil } needPasswd := true needGroup := true // First, check if there's a mount at /etc/passwd or group, we don't // want to interfere with user mounts. if MountExists(c.config.Spec.Mounts, "/etc/passwd") { needPasswd = false } if MountExists(c.config.Spec.Mounts, "/etc/group") { needGroup = false } // Next, check if we already made the files. If we didn't, don't need to // do anything more. if needPasswd { passwdPath := filepath.Join(c.config.StaticDir, "passwd") if _, err := os.Stat(passwdPath); err == nil { needPasswd = false } } if needGroup { groupPath := filepath.Join(c.config.StaticDir, "group") if _, err := os.Stat(groupPath); err == nil { needGroup = false } } // Next, check if the container even has a /etc/passwd or /etc/group. // If it doesn't we don't want to create them ourselves. if needPasswd { exists, err := c.checkFileExistsInRootfs("/etc/passwd") if err != nil { return "", "", err } needPasswd = exists } if needGroup { exists, err := c.checkFileExistsInRootfs("/etc/group") if err != nil { return "", "", err } needGroup = exists } // If we don't need a /etc/passwd or /etc/group at this point we can // just return. if !needPasswd && !needGroup { return "", "", nil } passwdPath := "" groupPath := "" ro := c.IsReadOnly() if needPasswd { passwdEntry, err := c.generatePasswdEntry() if err != nil { return "", "", err } needsWrite := passwdEntry != "" switch { case ro && needsWrite: logrus.Debugf("Making /etc/passwd for container %s", c.ID()) originPasswdFile, err := securejoin.SecureJoin(c.state.Mountpoint, "/etc/passwd") if err != nil { return "", "", errors.Wrapf(err, "error creating path to container %s /etc/passwd", c.ID()) } orig, err := ioutil.ReadFile(originPasswdFile) if err != nil && !os.IsNotExist(err) { return "", "", err } passwdFile, err := c.writeStringToStaticDir("passwd", string(orig)+passwdEntry) if err != nil { return "", "", errors.Wrapf(err, "failed to create temporary passwd file") } if err := os.Chmod(passwdFile, 0644); err != nil { return "", "", err } passwdPath = passwdFile case !ro && needsWrite: logrus.Debugf("Modifying container %s /etc/passwd", c.ID()) containerPasswd, err := securejoin.SecureJoin(c.state.Mountpoint, "/etc/passwd") if err != nil { return "", "", errors.Wrapf(err, "error looking up location of container %s /etc/passwd", c.ID()) } f, err := os.OpenFile(containerPasswd, os.O_APPEND|os.O_WRONLY, 0600) if err != nil { return "", "", errors.Wrapf(err, "container %s", c.ID()) } defer f.Close() if _, err := f.WriteString(passwdEntry); err != nil { return "", "", errors.Wrapf(err, "unable to append to container %s /etc/passwd", c.ID()) } default: logrus.Debugf("Not modifying container %s /etc/passwd", c.ID()) } } if needGroup { groupEntry, err := c.generateGroupEntry() if err != nil { return "", "", err } needsWrite := groupEntry != "" switch { case ro && needsWrite: logrus.Debugf("Making /etc/group for container %s", c.ID()) originGroupFile, err := securejoin.SecureJoin(c.state.Mountpoint, "/etc/group") if err != nil { return "", "", errors.Wrapf(err, "error creating path to container %s /etc/group", c.ID()) } orig, err := ioutil.ReadFile(originGroupFile) if err != nil && !os.IsNotExist(err) { return "", "", err } groupFile, err := c.writeStringToStaticDir("group", string(orig)+groupEntry) if err != nil { return "", "", errors.Wrapf(err, "failed to create temporary group file") } if err := os.Chmod(groupFile, 0644); err != nil { return "", "", err } groupPath = groupFile case !ro && needsWrite: logrus.Debugf("Modifying container %s /etc/group", c.ID()) containerGroup, err := securejoin.SecureJoin(c.state.Mountpoint, "/etc/group") if err != nil { return "", "", errors.Wrapf(err, "error looking up location of container %s /etc/group", c.ID()) } f, err := os.OpenFile(containerGroup, os.O_APPEND|os.O_WRONLY, 0600) if err != nil { return "", "", errors.Wrapf(err, "container %s", c.ID()) } defer f.Close() if _, err := f.WriteString(groupEntry); err != nil { return "", "", errors.Wrapf(err, "unable to append to container %s /etc/group", c.ID()) } default: logrus.Debugf("Not modifying container %s /etc/group", c.ID()) } } return passwdPath, groupPath, nil } // Get cgroup path in a format suitable for the OCI spec func (c *Container) getOCICgroupPath() (string, error) { unified, err := cgroups.IsCgroup2UnifiedMode() if err != nil { return "", err } cgroupManager := c.CgroupManager() switch { case (rootless.IsRootless() && !unified) || c.config.NoCgroups: return "", nil case c.config.CgroupsMode == cgroupSplit: if c.config.CgroupParent != "" { return c.config.CgroupParent, nil } selfCgroup, err := utils.GetOwnCgroup() if err != nil { return "", err } return filepath.Join(selfCgroup, "container"), nil case cgroupManager == config.SystemdCgroupsManager: // When the OCI runtime is set to use Systemd as a cgroup manager, it // expects cgroups to be passed as follows: // slice:prefix:name systemdCgroups := fmt.Sprintf("%s:libpod:%s", path.Base(c.config.CgroupParent), c.ID()) logrus.Debugf("Setting CGroups for container %s to %s", c.ID(), systemdCgroups) return systemdCgroups, nil case cgroupManager == config.CgroupfsCgroupsManager: cgroupPath := filepath.Join(c.config.CgroupParent, fmt.Sprintf("libpod-%s", c.ID())) logrus.Debugf("Setting CGroup path for container %s to %s", c.ID(), cgroupPath) return cgroupPath, nil default: return "", errors.Wrapf(define.ErrInvalidArg, "invalid cgroup manager %s requested", cgroupManager) } } func (c *Container) copyTimezoneFile(zonePath string) (string, error) { var localtimeCopy string = filepath.Join(c.state.RunDir, "localtime") file, err := os.Stat(zonePath) if err != nil { return "", err } if file.IsDir() { return "", errors.New("Invalid timezone: is a directory") } src, err := os.Open(zonePath) if err != nil { return "", err } defer src.Close() dest, err := os.Create(localtimeCopy) if err != nil { return "", err } defer dest.Close() _, err = io.Copy(dest, src) if err != nil { return "", err } if err := label.Relabel(localtimeCopy, c.config.MountLabel, false); err != nil { return "", err } if err := dest.Chown(c.RootUID(), c.RootGID()); err != nil { return "", err } return localtimeCopy, err } func (c *Container) cleanupOverlayMounts() error { return overlay.CleanupContent(c.config.StaticDir) } // Check if a file exists at the given path in the container's root filesystem. // Container must already be mounted for this to be used. func (c *Container) checkFileExistsInRootfs(file string) (bool, error) { checkPath, err := securejoin.SecureJoin(c.state.Mountpoint, file) if err != nil { return false, errors.Wrapf(err, "cannot create path to container %s file %q", c.ID(), file) } stat, err := os.Stat(checkPath) if err != nil { if os.IsNotExist(err) { return false, nil } return false, errors.Wrapf(err, "container %s", c.ID()) } if stat.IsDir() { return false, nil } return true, nil } // Creates and mounts an empty dir to mount secrets into, if it does not already exist func (c *Container) createSecretMountDir() error { src := filepath.Join(c.state.RunDir, "/run/secrets") _, err := os.Stat(src) if os.IsNotExist(err) { oldUmask := umask.Set(0) defer umask.Set(oldUmask) if err := os.MkdirAll(src, 0644); err != nil { return err } if err := label.Relabel(src, c.config.MountLabel, false); err != nil { return err } if err := os.Chown(src, c.RootUID(), c.RootGID()); err != nil { return err } c.state.BindMounts["/run/secrets"] = src return nil } return err }