package daemon import ( "fmt" "io" "os" "os/exec" "path/filepath" "sort" "strconv" "strings" "github.com/Sirupsen/logrus" containertypes "github.com/docker/docker/api/types/container" "github.com/docker/docker/container" "github.com/docker/docker/daemon/caps" "github.com/docker/docker/oci" "github.com/docker/docker/pkg/idtools" "github.com/docker/docker/pkg/mount" "github.com/docker/docker/pkg/stringutils" "github.com/docker/docker/pkg/symlink" "github.com/docker/docker/volume" "github.com/opencontainers/runc/libcontainer/apparmor" "github.com/opencontainers/runc/libcontainer/cgroups" "github.com/opencontainers/runc/libcontainer/devices" "github.com/opencontainers/runc/libcontainer/user" specs "github.com/opencontainers/runtime-spec/specs-go" ) func setResources(s *specs.Spec, r containertypes.Resources) error { weightDevices, err := getBlkioWeightDevices(r) if err != nil { return err } readBpsDevice, err := getBlkioThrottleDevices(r.BlkioDeviceReadBps) if err != nil { return err } writeBpsDevice, err := getBlkioThrottleDevices(r.BlkioDeviceWriteBps) if err != nil { return err } readIOpsDevice, err := getBlkioThrottleDevices(r.BlkioDeviceReadIOps) if err != nil { return err } writeIOpsDevice, err := getBlkioThrottleDevices(r.BlkioDeviceWriteIOps) if err != nil { return err } memoryRes := getMemoryResources(r) cpuRes := getCPUResources(r) blkioWeight := r.BlkioWeight specResources := &specs.Resources{ Memory: memoryRes, CPU: cpuRes, BlockIO: &specs.BlockIO{ Weight: &blkioWeight, WeightDevice: weightDevices, ThrottleReadBpsDevice: readBpsDevice, ThrottleWriteBpsDevice: writeBpsDevice, ThrottleReadIOPSDevice: readIOpsDevice, ThrottleWriteIOPSDevice: writeIOpsDevice, }, DisableOOMKiller: r.OomKillDisable, Pids: &specs.Pids{ Limit: &r.PidsLimit, }, } if s.Linux.Resources != nil && len(s.Linux.Resources.Devices) > 0 { specResources.Devices = s.Linux.Resources.Devices } s.Linux.Resources = specResources return nil } func setDevices(s *specs.Spec, c *container.Container) error { // Build lists of devices allowed and created within the container. var devs []specs.Device devPermissions := s.Linux.Resources.Devices if c.HostConfig.Privileged { hostDevices, err := devices.HostDevices() if err != nil { return err } for _, d := range hostDevices { devs = append(devs, specDevice(d)) } rwm := "rwm" devPermissions = []specs.DeviceCgroup{ { Allow: true, Access: &rwm, }, } } else { for _, deviceMapping := range c.HostConfig.Devices { d, dPermissions, err := getDevicesFromPath(deviceMapping) if err != nil { return err } devs = append(devs, d...) devPermissions = append(devPermissions, dPermissions...) } } s.Linux.Devices = append(s.Linux.Devices, devs...) s.Linux.Resources.Devices = devPermissions return nil } func setRlimits(daemon *Daemon, s *specs.Spec, c *container.Container) error { var rlimits []specs.Rlimit // We want to leave the original HostConfig alone so make a copy here hostConfig := *c.HostConfig // Merge with the daemon defaults daemon.mergeUlimits(&hostConfig) for _, ul := range hostConfig.Ulimits { rlimits = append(rlimits, specs.Rlimit{ Type: "RLIMIT_" + strings.ToUpper(ul.Name), Soft: uint64(ul.Soft), Hard: uint64(ul.Hard), }) } s.Process.Rlimits = rlimits return nil } func setUser(s *specs.Spec, c *container.Container) error { uid, gid, additionalGids, err := getUser(c, c.Config.User) if err != nil { return err } s.Process.User.UID = uid s.Process.User.GID = gid s.Process.User.AdditionalGids = additionalGids return nil } func readUserFile(c *container.Container, p string) (io.ReadCloser, error) { fp, err := symlink.FollowSymlinkInScope(filepath.Join(c.BaseFS, p), c.BaseFS) if err != nil { return nil, err } return os.Open(fp) } func getUser(c *container.Container, username string) (uint32, uint32, []uint32, error) { passwdPath, err := user.GetPasswdPath() if err != nil { return 0, 0, nil, err } groupPath, err := user.GetGroupPath() if err != nil { return 0, 0, nil, err } passwdFile, err := readUserFile(c, passwdPath) if err == nil { defer passwdFile.Close() } groupFile, err := readUserFile(c, groupPath) if err == nil { defer groupFile.Close() } execUser, err := user.GetExecUser(username, nil, passwdFile, groupFile) if err != nil { return 0, 0, nil, err } // todo: fix this double read by a change to libcontainer/user pkg groupFile, err = readUserFile(c, groupPath) if err == nil { defer groupFile.Close() } var addGroups []int if len(c.HostConfig.GroupAdd) > 0 { addGroups, err = user.GetAdditionalGroups(c.HostConfig.GroupAdd, groupFile) if err != nil { return 0, 0, nil, err } } uid := uint32(execUser.Uid) gid := uint32(execUser.Gid) sgids := append(execUser.Sgids, addGroups...) var additionalGids []uint32 for _, g := range sgids { additionalGids = append(additionalGids, uint32(g)) } return uid, gid, additionalGids, nil } func setNamespace(s *specs.Spec, ns specs.Namespace) { for i, n := range s.Linux.Namespaces { if n.Type == ns.Type { s.Linux.Namespaces[i] = ns return } } s.Linux.Namespaces = append(s.Linux.Namespaces, ns) } func setCapabilities(s *specs.Spec, c *container.Container) error { var caplist []string var err error if c.HostConfig.Privileged { caplist = caps.GetAllCapabilities() } else { caplist, err = caps.TweakCapabilities(s.Process.Capabilities, c.HostConfig.CapAdd, c.HostConfig.CapDrop) if err != nil { return err } } s.Process.Capabilities = caplist return nil } func delNamespace(s *specs.Spec, nsType specs.NamespaceType) { idx := -1 for i, n := range s.Linux.Namespaces { if n.Type == nsType { idx = i } } if idx >= 0 { s.Linux.Namespaces = append(s.Linux.Namespaces[:idx], s.Linux.Namespaces[idx+1:]...) } } func setNamespaces(daemon *Daemon, s *specs.Spec, c *container.Container) error { userNS := false // user if c.HostConfig.UsernsMode.IsPrivate() { uidMap, gidMap := daemon.GetUIDGIDMaps() if uidMap != nil { userNS = true ns := specs.Namespace{Type: "user"} setNamespace(s, ns) s.Linux.UIDMappings = specMapping(uidMap) s.Linux.GIDMappings = specMapping(gidMap) } } // network if !c.Config.NetworkDisabled { ns := specs.Namespace{Type: "network"} parts := strings.SplitN(string(c.HostConfig.NetworkMode), ":", 2) if parts[0] == "container" { nc, err := daemon.getNetworkedContainer(c.ID, c.HostConfig.NetworkMode.ConnectedContainer()) if err != nil { return err } ns.Path = fmt.Sprintf("/proc/%d/ns/net", nc.State.GetPID()) if userNS { // to share a net namespace, they must also share a user namespace nsUser := specs.Namespace{Type: "user"} nsUser.Path = fmt.Sprintf("/proc/%d/ns/user", nc.State.GetPID()) setNamespace(s, nsUser) } } else if c.HostConfig.NetworkMode.IsHost() { ns.Path = c.NetworkSettings.SandboxKey } setNamespace(s, ns) } // ipc if c.HostConfig.IpcMode.IsContainer() { ns := specs.Namespace{Type: "ipc"} ic, err := daemon.getIpcContainer(c) if err != nil { return err } ns.Path = fmt.Sprintf("/proc/%d/ns/ipc", ic.State.GetPID()) setNamespace(s, ns) if userNS { // to share an IPC namespace, they must also share a user namespace nsUser := specs.Namespace{Type: "user"} nsUser.Path = fmt.Sprintf("/proc/%d/ns/user", ic.State.GetPID()) setNamespace(s, nsUser) } } else if c.HostConfig.IpcMode.IsHost() { delNamespace(s, specs.NamespaceType("ipc")) } else { ns := specs.Namespace{Type: "ipc"} setNamespace(s, ns) } // pid if c.HostConfig.PidMode.IsContainer() { ns := specs.Namespace{Type: "pid"} pc, err := daemon.getPidContainer(c) if err != nil { return err } ns.Path = fmt.Sprintf("/proc/%d/ns/pid", pc.State.GetPID()) setNamespace(s, ns) if userNS { // to share a PID namespace, they must also share a user namespace nsUser := specs.Namespace{Type: "user"} nsUser.Path = fmt.Sprintf("/proc/%d/ns/user", pc.State.GetPID()) setNamespace(s, nsUser) } } else if c.HostConfig.PidMode.IsHost() { delNamespace(s, specs.NamespaceType("pid")) } else { ns := specs.Namespace{Type: "pid"} setNamespace(s, ns) } // uts if c.HostConfig.UTSMode.IsHost() { delNamespace(s, specs.NamespaceType("uts")) s.Hostname = "" } return nil } func specMapping(s []idtools.IDMap) []specs.IDMapping { var ids []specs.IDMapping for _, item := range s { ids = append(ids, specs.IDMapping{ HostID: uint32(item.HostID), ContainerID: uint32(item.ContainerID), Size: uint32(item.Size), }) } return ids } func getMountInfo(mountinfo []*mount.Info, dir string) *mount.Info { for _, m := range mountinfo { if m.Mountpoint == dir { return m } } return nil } // Get the source mount point of directory passed in as argument. Also return // optional fields. func getSourceMount(source string) (string, string, error) { // Ensure any symlinks are resolved. sourcePath, err := filepath.EvalSymlinks(source) if err != nil { return "", "", err } mountinfos, err := mount.GetMounts() if err != nil { return "", "", err } mountinfo := getMountInfo(mountinfos, sourcePath) if mountinfo != nil { return sourcePath, mountinfo.Optional, nil } path := sourcePath for { path = filepath.Dir(path) mountinfo = getMountInfo(mountinfos, path) if mountinfo != nil { return path, mountinfo.Optional, nil } if path == "/" { break } } // If we are here, we did not find parent mount. Something is wrong. return "", "", fmt.Errorf("Could not find source mount of %s", source) } // Ensure mount point on which path is mounted, is shared. func ensureShared(path string) error { sharedMount := false sourceMount, optionalOpts, err := getSourceMount(path) if err != nil { return err } // Make sure source mount point is shared. optsSplit := strings.Split(optionalOpts, " ") for _, opt := range optsSplit { if strings.HasPrefix(opt, "shared:") { sharedMount = true break } } if !sharedMount { return fmt.Errorf("Path %s is mounted on %s but it is not a shared mount.", path, sourceMount) } return nil } // Ensure mount point on which path is mounted, is either shared or slave. func ensureSharedOrSlave(path string) error { sharedMount := false slaveMount := false sourceMount, optionalOpts, err := getSourceMount(path) if err != nil { return err } // Make sure source mount point is shared. optsSplit := strings.Split(optionalOpts, " ") for _, opt := range optsSplit { if strings.HasPrefix(opt, "shared:") { sharedMount = true break } else if strings.HasPrefix(opt, "master:") { slaveMount = true break } } if !sharedMount && !slaveMount { return fmt.Errorf("Path %s is mounted on %s but it is not a shared or slave mount.", path, sourceMount) } return nil } var ( mountPropagationMap = map[string]int{ "private": mount.PRIVATE, "rprivate": mount.RPRIVATE, "shared": mount.SHARED, "rshared": mount.RSHARED, "slave": mount.SLAVE, "rslave": mount.RSLAVE, } mountPropagationReverseMap = map[int]string{ mount.PRIVATE: "private", mount.RPRIVATE: "rprivate", mount.SHARED: "shared", mount.RSHARED: "rshared", mount.SLAVE: "slave", mount.RSLAVE: "rslave", } ) func setMounts(daemon *Daemon, s *specs.Spec, c *container.Container, mounts []container.Mount) error { userMounts := make(map[string]struct{}) for _, m := range mounts { userMounts[m.Destination] = struct{}{} } // Filter out mounts that are overridden by user supplied mounts var defaultMounts []specs.Mount _, mountDev := userMounts["/dev"] for _, m := range s.Mounts { if _, ok := userMounts[m.Destination]; !ok { if mountDev && strings.HasPrefix(m.Destination, "/dev/") { continue } defaultMounts = append(defaultMounts, m) } } s.Mounts = defaultMounts for _, m := range mounts { for _, cm := range s.Mounts { if cm.Destination == m.Destination { return fmt.Errorf("Duplicate mount point '%s'", m.Destination) } } if m.Source == "tmpfs" { data := m.Data options := []string{"noexec", "nosuid", "nodev", string(volume.DefaultPropagationMode)} if data != "" { options = append(options, strings.Split(data, ",")...) } merged, err := mount.MergeTmpfsOptions(options) if err != nil { return err } s.Mounts = append(s.Mounts, specs.Mount{Destination: m.Destination, Source: m.Source, Type: "tmpfs", Options: merged}) continue } mt := specs.Mount{Destination: m.Destination, Source: m.Source, Type: "bind"} // 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. pFlag := mountPropagationMap[m.Propagation] if pFlag == mount.SHARED || pFlag == mount.RSHARED { if err := ensureShared(m.Source); err != nil { return err } rootpg := mountPropagationMap[s.Linux.RootfsPropagation] if rootpg != mount.SHARED && rootpg != mount.RSHARED { s.Linux.RootfsPropagation = mountPropagationReverseMap[mount.SHARED] } } else if pFlag == mount.SLAVE || pFlag == mount.RSLAVE { if err := ensureSharedOrSlave(m.Source); err != nil { return err } rootpg := mountPropagationMap[s.Linux.RootfsPropagation] if rootpg != mount.SHARED && rootpg != mount.RSHARED && rootpg != mount.SLAVE && rootpg != mount.RSLAVE { s.Linux.RootfsPropagation = mountPropagationReverseMap[mount.RSLAVE] } } opts := []string{"rbind"} if !m.Writable { opts = append(opts, "ro") } if pFlag != 0 { opts = append(opts, mountPropagationReverseMap[pFlag]) } mt.Options = opts s.Mounts = append(s.Mounts, mt) } if s.Root.Readonly { for i, m := range s.Mounts { switch m.Destination { case "/proc", "/dev/pts", "/dev/mqueue": // /dev is remounted by runc continue } if _, ok := userMounts[m.Destination]; !ok { if !stringutils.InSlice(m.Options, "ro") { s.Mounts[i].Options = append(s.Mounts[i].Options, "ro") } } } } if c.HostConfig.Privileged { if !s.Root.Readonly { // clear readonly for /sys for i := range s.Mounts { if s.Mounts[i].Destination == "/sys" { clearReadOnly(&s.Mounts[i]) } } } s.Linux.ReadonlyPaths = nil s.Linux.MaskedPaths = nil } // TODO: until a kernel/mount solution exists for handling remount in a user namespace, // we must clear the readonly flag for the cgroups mount (@mrunalp concurs) if uidMap, _ := daemon.GetUIDGIDMaps(); uidMap != nil || c.HostConfig.Privileged { for i, m := range s.Mounts { if m.Type == "cgroup" { clearReadOnly(&s.Mounts[i]) } } } return nil } func (daemon *Daemon) populateCommonSpec(s *specs.Spec, c *container.Container) error { linkedEnv, err := daemon.setupLinkedContainers(c) if err != nil { return err } s.Root = specs.Root{ Path: c.BaseFS, Readonly: c.HostConfig.ReadonlyRootfs, } rootUID, rootGID := daemon.GetRemappedUIDGID() if err := c.SetupWorkingDirectory(rootUID, rootGID); err != nil { return err } cwd := c.Config.WorkingDir if len(cwd) == 0 { cwd = "/" } s.Process.Args = append([]string{c.Path}, c.Args...) // only add the custom init if it is specified and the container is running in its // own private pid namespace. It does not make sense to add if it is running in the // host namespace or another container's pid namespace where we already have an init if c.HostConfig.PidMode.IsPrivate() { if (c.HostConfig.Init != nil && *c.HostConfig.Init) || (c.HostConfig.Init == nil && daemon.configStore.Init) { s.Process.Args = append([]string{"/dev/init", c.Path}, c.Args...) var path string if daemon.configStore.InitPath == "" && c.HostConfig.InitPath == "" { path, err = exec.LookPath("docker-init") if err != nil { return err } } if daemon.configStore.InitPath != "" { path = daemon.configStore.InitPath } if c.HostConfig.InitPath != "" { path = c.HostConfig.InitPath } s.Mounts = append(s.Mounts, specs.Mount{ Destination: "/dev/init", Type: "bind", Source: path, Options: []string{"bind", "ro"}, }) } } s.Process.Cwd = cwd s.Process.Env = c.CreateDaemonEnvironment(c.Config.Tty, linkedEnv) s.Process.Terminal = c.Config.Tty s.Hostname = c.FullHostname() return nil } func (daemon *Daemon) createSpec(c *container.Container) (*specs.Spec, error) { s := oci.DefaultSpec() if err := daemon.populateCommonSpec(&s, c); err != nil { return nil, err } var cgroupsPath string scopePrefix := "docker" parent := "/docker" useSystemd := UsingSystemd(daemon.configStore) if useSystemd { parent = "system.slice" } if c.HostConfig.CgroupParent != "" { parent = c.HostConfig.CgroupParent } else if daemon.configStore.CgroupParent != "" { parent = daemon.configStore.CgroupParent } if useSystemd { cgroupsPath = parent + ":" + scopePrefix + ":" + c.ID logrus.Debugf("createSpec: cgroupsPath: %s", cgroupsPath) } else { cgroupsPath = filepath.Join(parent, c.ID) } s.Linux.CgroupsPath = &cgroupsPath if err := setResources(&s, c.HostConfig.Resources); err != nil { return nil, fmt.Errorf("linux runtime spec resources: %v", err) } s.Linux.Resources.OOMScoreAdj = &c.HostConfig.OomScoreAdj s.Linux.Sysctl = c.HostConfig.Sysctls p := *s.Linux.CgroupsPath if useSystemd { initPath, err := cgroups.GetInitCgroupDir("cpu") if err != nil { return nil, err } p, _ = cgroups.GetThisCgroupDir("cpu") if err != nil { return nil, err } p = filepath.Join(initPath, p) } // Clean path to guard against things like ../../../BAD parentPath := filepath.Dir(p) if !filepath.IsAbs(parentPath) { parentPath = filepath.Clean("/" + parentPath) } if err := daemon.initCgroupsPath(parentPath); err != nil { return nil, fmt.Errorf("linux init cgroups path: %v", err) } if err := setDevices(&s, c); err != nil { return nil, fmt.Errorf("linux runtime spec devices: %v", err) } if err := setRlimits(daemon, &s, c); err != nil { return nil, fmt.Errorf("linux runtime spec rlimits: %v", err) } if err := setUser(&s, c); err != nil { return nil, fmt.Errorf("linux spec user: %v", err) } if err := setNamespaces(daemon, &s, c); err != nil { return nil, fmt.Errorf("linux spec namespaces: %v", err) } if err := setCapabilities(&s, c); err != nil { return nil, fmt.Errorf("linux spec capabilities: %v", err) } if err := setSeccomp(daemon, &s, c); err != nil { return nil, fmt.Errorf("linux seccomp: %v", err) } if err := daemon.setupIpcDirs(c); err != nil { return nil, err } if err := daemon.setupSecretDir(c); err != nil { return nil, err } ms, err := daemon.setupMounts(c) if err != nil { return nil, err } ms = append(ms, c.IpcMounts()...) tmpfsMounts, err := c.TmpfsMounts() if err != nil { return nil, err } ms = append(ms, tmpfsMounts...) if m := c.SecretMount(); m != nil { ms = append(ms, *m) } sort.Sort(mounts(ms)) if err := setMounts(daemon, &s, c, ms); err != nil { return nil, fmt.Errorf("linux mounts: %v", err) } for _, ns := range s.Linux.Namespaces { if ns.Type == "network" && ns.Path == "" && !c.Config.NetworkDisabled { target, err := os.Readlink(filepath.Join("/proc", strconv.Itoa(os.Getpid()), "exe")) if err != nil { return nil, err } s.Hooks = specs.Hooks{ Prestart: []specs.Hook{{ Path: target, // FIXME: cross-platform Args: []string{"libnetwork-setkey", c.ID, daemon.netController.ID()}, }}, } } } if apparmor.IsEnabled() { appArmorProfile := "docker-default" if len(c.AppArmorProfile) > 0 { appArmorProfile = c.AppArmorProfile } else if c.HostConfig.Privileged { appArmorProfile = "unconfined" } s.Process.ApparmorProfile = appArmorProfile } s.Process.SelinuxLabel = c.GetProcessLabel() s.Process.NoNewPrivileges = c.NoNewPrivileges s.Linux.MountLabel = c.MountLabel return (*specs.Spec)(&s), nil } func clearReadOnly(m *specs.Mount) { var opt []string for _, o := range m.Options { if o != "ro" { opt = append(opt, o) } } m.Options = opt } // mergeUlimits merge the Ulimits from HostConfig with daemon defaults, and update HostConfig func (daemon *Daemon) mergeUlimits(c *containertypes.HostConfig) { ulimits := c.Ulimits // Merge ulimits with daemon defaults ulIdx := make(map[string]struct{}) for _, ul := range ulimits { ulIdx[ul.Name] = struct{}{} } for name, ul := range daemon.configStore.Ulimits { if _, exists := ulIdx[name]; !exists { ulimits = append(ulimits, ul) } } c.Ulimits = ulimits }