// +build linux package main import ( "encoding/json" "fmt" "io/ioutil" "os" "path/filepath" "runtime" "strconv" "strings" "syscall" "github.com/codegangsta/cli" "github.com/opencontainers/runc/libcontainer/cgroups" "github.com/opencontainers/runc/libcontainer/configs" "github.com/opencontainers/runc/libcontainer/seccomp" libcontainerUtils "github.com/opencontainers/runc/libcontainer/utils" "github.com/opencontainers/specs" ) var specCommand = cli.Command{ Name: "spec", Usage: "create a new specification file", ArgsUsage: "", Description: `The spec command creates the new specification file named "` + specConfig + `" for the bundle." `, Flags: []cli.Flag{ cli.StringFlag{ Name: "bundle, b", Value: "", Usage: "path to the root of the bundle directory", }, }, Action: func(context *cli.Context) { spec := specs.LinuxSpec{ Spec: specs.Spec{ Version: specs.Version, Platform: specs.Platform{ OS: runtime.GOOS, Arch: runtime.GOARCH, }, Root: specs.Root{ Path: "rootfs", Readonly: true, }, Process: specs.Process{ Terminal: true, User: specs.User{}, Args: []string{ "sh", }, Env: []string{ "PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin", "TERM=xterm", }, Cwd: "/", NoNewPrivileges: true, Capabilities: []string{ "CAP_AUDIT_WRITE", "CAP_KILL", "CAP_NET_BIND_SERVICE", }, }, Hostname: "shell", Mounts: []specs.Mount{ { Destination: "/proc", Type: "proc", Source: "proc", Options: nil, }, { Destination: "/dev", Type: "tmpfs", Source: "tmpfs", Options: []string{"nosuid", "strictatime", "mode=755", "size=65536k"}, }, { Destination: "/dev/pts", Type: "devpts", Source: "devpts", Options: []string{"nosuid", "noexec", "newinstance", "ptmxmode=0666", "mode=0620", "gid=5"}, }, { Destination: "/dev/shm", Type: "tmpfs", Source: "shm", Options: []string{"nosuid", "noexec", "nodev", "mode=1777", "size=65536k"}, }, { Destination: "/dev/mqueue", Type: "mqueue", Source: "mqueue", Options: []string{"nosuid", "noexec", "nodev"}, }, { Destination: "/sys", Type: "sysfs", Source: "sysfs", Options: []string{"nosuid", "noexec", "nodev", "ro"}, }, { Destination: "/sys/fs/cgroup", Type: "cgroup", Source: "cgroup", Options: []string{"nosuid", "noexec", "nodev", "relatime", "ro"}, }, }, }, Linux: specs.Linux{ Resources: &specs.Resources{ Devices: []specs.DeviceCgroup{ { Allow: false, Access: sPtr("rwm"), }, }, }, Namespaces: []specs.Namespace{ { Type: "pid", }, { Type: "network", }, { Type: "ipc", }, { Type: "uts", }, { Type: "mount", }, }, Rlimits: []specs.Rlimit{ { Type: "RLIMIT_NOFILE", Hard: uint64(1024), Soft: uint64(1024), }, }, }, } checkNoFile := func(name string) error { _, err := os.Stat(name) if err == nil { return fmt.Errorf("File %s exists. Remove it first", name) } if !os.IsNotExist(err) { return err } return nil } bundle := context.String("bundle") if bundle != "" { if err := os.Chdir(bundle); err != nil { fatal(err) } } if err := checkNoFile(specConfig); err != nil { fatal(err) } data, err := json.MarshalIndent(&spec, "", "\t") if err != nil { fatal(err) } if err := ioutil.WriteFile(specConfig, data, 0666); err != nil { fatal(err) } }, } func sPtr(s string) *string { return &s } func rPtr(r rune) *rune { return &r } func iPtr(i int64) *int64 { return &i } func u32Ptr(i int64) *uint32 { u := uint32(i); return &u } func fmPtr(i int64) *os.FileMode { fm := os.FileMode(i); return &fm } var namespaceMapping = map[specs.NamespaceType]configs.NamespaceType{ specs.PIDNamespace: configs.NEWPID, specs.NetworkNamespace: configs.NEWNET, specs.MountNamespace: configs.NEWNS, specs.UserNamespace: configs.NEWUSER, specs.IPCNamespace: configs.NEWIPC, specs.UTSNamespace: configs.NEWUTS, } var mountPropagationMapping = map[string]int{ "rprivate": syscall.MS_PRIVATE | syscall.MS_REC, "private": syscall.MS_PRIVATE, "rslave": syscall.MS_SLAVE | syscall.MS_REC, "slave": syscall.MS_SLAVE, "rshared": syscall.MS_SHARED | syscall.MS_REC, "shared": syscall.MS_SHARED, "": syscall.MS_PRIVATE | syscall.MS_REC, } // validateSpec validates the fields in the spec // TODO: Add validation for other fields where applicable func validateSpec(spec *specs.LinuxSpec) error { if spec.Process.Cwd == "" { return fmt.Errorf("Cwd property must not be empty") } if !filepath.IsAbs(spec.Process.Cwd) { return fmt.Errorf("Cwd must be an absolute path") } return nil } // loadSpec loads the specification from the provided path. // If the path is empty then the default path will be "config.json" func loadSpec(cPath string) (spec *specs.LinuxSpec, err error) { cf, err := os.Open(cPath) if err != nil { if os.IsNotExist(err) { return nil, fmt.Errorf("JSON specification file %s not found", cPath) } return nil, err } defer cf.Close() if err = json.NewDecoder(cf).Decode(&spec); err != nil { return nil, err } return spec, validateSpec(spec) } func createLibcontainerConfig(cgroupName string, spec *specs.LinuxSpec) (*configs.Config, error) { // runc's cwd will always be the bundle path rcwd, err := os.Getwd() if err != nil { return nil, err } cwd, err := filepath.Abs(rcwd) if err != nil { return nil, err } rootfsPath := spec.Root.Path if !filepath.IsAbs(rootfsPath) { rootfsPath = filepath.Join(cwd, rootfsPath) } config := &configs.Config{ Rootfs: rootfsPath, Readonlyfs: spec.Root.Readonly, Hostname: spec.Hostname, Labels: []string{ "bundle=" + cwd, }, } exists := false if config.RootPropagation, exists = mountPropagationMapping[spec.Linux.RootfsPropagation]; !exists { return nil, fmt.Errorf("rootfsPropagation=%v is not supported", spec.Linux.RootfsPropagation) } for _, ns := range spec.Linux.Namespaces { t, exists := namespaceMapping[ns.Type] if !exists { return nil, fmt.Errorf("namespace %q does not exist", ns) } config.Namespaces.Add(t, ns.Path) } if config.Namespaces.Contains(configs.NEWNET) { config.Networks = []*configs.Network{ { Type: "loopback", }, } } for _, m := range spec.Mounts { config.Mounts = append(config.Mounts, createLibcontainerMount(cwd, m)) } if err := createDevices(spec, config); err != nil { return nil, err } if err := setupUserNamespace(spec, config); err != nil { return nil, err } for _, rlimit := range spec.Linux.Rlimits { rl, err := createLibContainerRlimit(rlimit) if err != nil { return nil, err } config.Rlimits = append(config.Rlimits, rl) } c, err := createCgroupConfig(cgroupName, spec) if err != nil { return nil, err } config.Cgroups = c // set extra path masking for libcontainer for the various unsafe places in proc config.MaskPaths = maskedPaths config.ReadonlyPaths = readonlyPaths seccomp, err := setupSeccomp(&spec.Linux.Seccomp) if err != nil { return nil, err } config.Seccomp = seccomp config.Sysctl = spec.Linux.Sysctl if oomScoreAdj := spec.Linux.Resources.OOMScoreAdj; oomScoreAdj != nil { config.OomScoreAdj = *oomScoreAdj } for _, g := range spec.Process.User.AdditionalGids { config.AdditionalGroups = append(config.AdditionalGroups, strconv.FormatUint(uint64(g), 10)) } createHooks(spec, config) config.Version = specs.Version return config, nil } func createLibcontainerMount(cwd string, m specs.Mount) *configs.Mount { flags, pgflags, data := parseMountOptions(m.Options) source := m.Source if m.Type == "bind" { if !filepath.IsAbs(source) { source = filepath.Join(cwd, m.Source) } } return &configs.Mount{ Device: m.Type, Source: source, Destination: m.Destination, Data: data, Flags: flags, PropagationFlags: pgflags, } } func createCgroupConfig(name string, spec *specs.LinuxSpec) (*configs.Cgroup, error) { var ( err error myCgroupPath string ) if spec.Linux.CgroupsPath != nil { myCgroupPath = libcontainerUtils.CleanPath(*spec.Linux.CgroupsPath) } else { myCgroupPath, err = cgroups.GetThisCgroupDir("devices") if err != nil { return nil, err } myCgroupPath = filepath.Join(myCgroupPath, name) } c := &configs.Cgroup{ Path: myCgroupPath, Resources: &configs.Resources{}, } c.Resources.AllowedDevices = allowedDevices r := spec.Linux.Resources if r == nil { return c, nil } for i, d := range spec.Linux.Resources.Devices { var ( t = "a" major = int64(-1) minor = int64(-1) ) if d.Type != nil { t = *d.Type } if d.Major != nil { major = *d.Major } if d.Minor != nil { minor = *d.Minor } if d.Access == nil || *d.Access == "" { return nil, fmt.Errorf("device access at %d field canot be empty", i) } dt, err := stringToDeviceRune(t) if err != nil { return nil, err } dd := &configs.Device{ Type: dt, Major: major, Minor: minor, Permissions: *d.Access, Allow: d.Allow, } c.Resources.Devices = append(c.Resources.Devices, dd) } // append the default allowed devices to the end of the list c.Resources.Devices = append(c.Resources.Devices, allowedDevices...) if r.Memory != nil { if r.Memory.Limit != nil { c.Resources.Memory = int64(*r.Memory.Limit) } if r.Memory.Reservation != nil { c.Resources.MemoryReservation = int64(*r.Memory.Reservation) } if r.Memory.Swap != nil { c.Resources.MemorySwap = int64(*r.Memory.Swap) } if r.Memory.Kernel != nil { c.Resources.KernelMemory = int64(*r.Memory.Kernel) } if r.Memory.Swappiness != nil { swappiness := int64(*r.Memory.Swappiness) c.Resources.MemorySwappiness = &swappiness } } if r.CPU != nil { if r.CPU.Shares != nil { c.Resources.CpuShares = int64(*r.CPU.Shares) } if r.CPU.Quota != nil { c.Resources.CpuQuota = int64(*r.CPU.Quota) } if r.CPU.Period != nil { c.Resources.CpuPeriod = int64(*r.CPU.Period) } if r.CPU.RealtimeRuntime != nil { c.Resources.CpuRtRuntime = int64(*r.CPU.RealtimeRuntime) } if r.CPU.RealtimePeriod != nil { c.Resources.CpuRtPeriod = int64(*r.CPU.RealtimePeriod) } if r.CPU.Cpus != nil { c.Resources.CpusetCpus = *r.CPU.Cpus } if r.CPU.Mems != nil { c.Resources.CpusetMems = *r.CPU.Mems } } if r.Pids != nil { c.Resources.PidsLimit = *r.Pids.Limit } if r.BlockIO != nil { if r.BlockIO.Weight != nil { c.Resources.BlkioWeight = *r.BlockIO.Weight } if r.BlockIO.LeafWeight != nil { c.Resources.BlkioLeafWeight = *r.BlockIO.LeafWeight } if r.BlockIO.WeightDevice != nil { for _, wd := range r.BlockIO.WeightDevice { weightDevice := configs.NewWeightDevice(wd.Major, wd.Minor, *wd.Weight, *wd.LeafWeight) c.Resources.BlkioWeightDevice = append(c.Resources.BlkioWeightDevice, weightDevice) } } if r.BlockIO.ThrottleReadBpsDevice != nil { for _, td := range r.BlockIO.ThrottleReadBpsDevice { throttleDevice := configs.NewThrottleDevice(td.Major, td.Minor, *td.Rate) c.Resources.BlkioThrottleReadBpsDevice = append(c.Resources.BlkioThrottleReadBpsDevice, throttleDevice) } } if r.BlockIO.ThrottleWriteBpsDevice != nil { for _, td := range r.BlockIO.ThrottleWriteBpsDevice { throttleDevice := configs.NewThrottleDevice(td.Major, td.Minor, *td.Rate) c.Resources.BlkioThrottleWriteBpsDevice = append(c.Resources.BlkioThrottleWriteBpsDevice, throttleDevice) } } if r.BlockIO.ThrottleReadIOPSDevice != nil { for _, td := range r.BlockIO.ThrottleReadIOPSDevice { throttleDevice := configs.NewThrottleDevice(td.Major, td.Minor, *td.Rate) c.Resources.BlkioThrottleReadIOPSDevice = append(c.Resources.BlkioThrottleReadIOPSDevice, throttleDevice) } } if r.BlockIO.ThrottleWriteIOPSDevice != nil { for _, td := range r.BlockIO.ThrottleWriteIOPSDevice { throttleDevice := configs.NewThrottleDevice(td.Major, td.Minor, *td.Rate) c.Resources.BlkioThrottleWriteIOPSDevice = append(c.Resources.BlkioThrottleWriteIOPSDevice, throttleDevice) } } } for _, l := range r.HugepageLimits { c.Resources.HugetlbLimit = append(c.Resources.HugetlbLimit, &configs.HugepageLimit{ Pagesize: *l.Pagesize, Limit: *l.Limit, }) } if r.DisableOOMKiller != nil { c.Resources.OomKillDisable = *r.DisableOOMKiller } if r.Network != nil { if r.Network.ClassID != nil { c.Resources.NetClsClassid = string(*r.Network.ClassID) } for _, m := range r.Network.Priorities { c.Resources.NetPrioIfpriomap = append(c.Resources.NetPrioIfpriomap, &configs.IfPrioMap{ Interface: m.Name, Priority: int64(m.Priority), }) } } return c, nil } func stringToDeviceRune(s string) (rune, error) { switch s { case "a": return 'a', nil case "b": return 'b', nil case "c": return 'c', nil default: return 0, fmt.Errorf("invalid device type %q", s) } } func createDevices(spec *specs.LinuxSpec, config *configs.Config) error { // add whitelisted devices config.Devices = []*configs.Device{ { Type: 'c', Path: "/dev/null", Major: 1, Minor: 3, FileMode: 0666, Uid: 0, Gid: 0, }, { Type: 'c', Path: "/dev/random", Major: 1, Minor: 8, FileMode: 0666, Uid: 0, Gid: 0, }, { Type: 'c', Path: "/dev/full", Major: 1, Minor: 7, FileMode: 0666, Uid: 0, Gid: 0, }, { Type: 'c', Path: "/dev/tty", Major: 5, Minor: 0, FileMode: 0666, Uid: 0, Gid: 0, }, { Type: 'c', Path: "/dev/zero", Major: 1, Minor: 5, FileMode: 0666, Uid: 0, Gid: 0, }, { Type: 'c', Path: "/dev/urandom", Major: 1, Minor: 9, FileMode: 0666, Uid: 0, Gid: 0, }, } // merge in additional devices from the spec for _, d := range spec.Linux.Devices { var uid, gid uint32 if d.UID != nil { uid = *d.UID } if d.GID != nil { gid = *d.GID } dt, err := stringToDeviceRune(d.Type) if err != nil { return err } device := &configs.Device{ Type: dt, Path: d.Path, Major: d.Major, Minor: d.Minor, FileMode: *d.FileMode, Uid: uid, Gid: gid, } config.Devices = append(config.Devices, device) } return nil } func setupUserNamespace(spec *specs.LinuxSpec, config *configs.Config) error { if len(spec.Linux.UIDMappings) == 0 { return nil } // do not override the specified user namespace path if config.Namespaces.PathOf(configs.NEWUSER) == "" { config.Namespaces.Add(configs.NEWUSER, "") } create := func(m specs.IDMapping) configs.IDMap { return configs.IDMap{ HostID: int(m.HostID), ContainerID: int(m.ContainerID), Size: int(m.Size), } } for _, m := range spec.Linux.UIDMappings { config.UidMappings = append(config.UidMappings, create(m)) } for _, m := range spec.Linux.GIDMappings { config.GidMappings = append(config.GidMappings, create(m)) } rootUID, err := config.HostUID() if err != nil { return err } rootGID, err := config.HostGID() if err != nil { return err } for _, node := range config.Devices { node.Uid = uint32(rootUID) node.Gid = uint32(rootGID) } return nil } func createLibContainerRlimit(rlimit specs.Rlimit) (configs.Rlimit, error) { rl, err := strToRlimit(rlimit.Type) if err != nil { return configs.Rlimit{}, err } return configs.Rlimit{ Type: rl, Hard: uint64(rlimit.Hard), Soft: uint64(rlimit.Soft), }, nil } // parseMountOptions parses the string and returns the flags, propagation // flags and any mount data that it contains. func parseMountOptions(options []string) (int, []int, string) { var ( flag int pgflag []int data []string ) flags := map[string]struct { clear bool flag int }{ "async": {true, syscall.MS_SYNCHRONOUS}, "atime": {true, syscall.MS_NOATIME}, "bind": {false, syscall.MS_BIND}, "defaults": {false, 0}, "dev": {true, syscall.MS_NODEV}, "diratime": {true, syscall.MS_NODIRATIME}, "dirsync": {false, syscall.MS_DIRSYNC}, "exec": {true, syscall.MS_NOEXEC}, "mand": {false, syscall.MS_MANDLOCK}, "noatime": {false, syscall.MS_NOATIME}, "nodev": {false, syscall.MS_NODEV}, "nodiratime": {false, syscall.MS_NODIRATIME}, "noexec": {false, syscall.MS_NOEXEC}, "nomand": {true, syscall.MS_MANDLOCK}, "norelatime": {true, syscall.MS_RELATIME}, "nostrictatime": {true, syscall.MS_STRICTATIME}, "nosuid": {false, syscall.MS_NOSUID}, "rbind": {false, syscall.MS_BIND | syscall.MS_REC}, "relatime": {false, syscall.MS_RELATIME}, "remount": {false, syscall.MS_REMOUNT}, "ro": {false, syscall.MS_RDONLY}, "rw": {true, syscall.MS_RDONLY}, "strictatime": {false, syscall.MS_STRICTATIME}, "suid": {true, syscall.MS_NOSUID}, "sync": {false, syscall.MS_SYNCHRONOUS}, } propagationFlags := map[string]struct { clear bool flag int }{ "private": {false, syscall.MS_PRIVATE}, "shared": {false, syscall.MS_SHARED}, "slave": {false, syscall.MS_SLAVE}, "unbindable": {false, syscall.MS_UNBINDABLE}, "rprivate": {false, syscall.MS_PRIVATE | syscall.MS_REC}, "rshared": {false, syscall.MS_SHARED | syscall.MS_REC}, "rslave": {false, syscall.MS_SLAVE | syscall.MS_REC}, "runbindable": {false, syscall.MS_UNBINDABLE | syscall.MS_REC}, } for _, o := range options { // If the option does not exist in the flags table or the flag // is not supported on the platform, // then it is a data value for a specific fs type if f, exists := flags[o]; exists && f.flag != 0 { if f.clear { flag &= ^f.flag } else { flag |= f.flag } } else if f, exists := propagationFlags[o]; exists && f.flag != 0 { pgflag = append(pgflag, f.flag) } else { data = append(data, o) } } return flag, pgflag, strings.Join(data, ",") } func setupSeccomp(config *specs.Seccomp) (*configs.Seccomp, error) { if config == nil { return nil, nil } // No default action specified, no syscalls listed, assume seccomp disabled if config.DefaultAction == "" && len(config.Syscalls) == 0 { return nil, nil } newConfig := new(configs.Seccomp) newConfig.Syscalls = []*configs.Syscall{} if len(config.Architectures) > 0 { newConfig.Architectures = []string{} for _, arch := range config.Architectures { newArch, err := seccomp.ConvertStringToArch(string(arch)) if err != nil { return nil, err } newConfig.Architectures = append(newConfig.Architectures, newArch) } } // Convert default action from string representation newDefaultAction, err := seccomp.ConvertStringToAction(string(config.DefaultAction)) if err != nil { return nil, err } newConfig.DefaultAction = newDefaultAction // Loop through all syscall blocks and convert them to libcontainer format for _, call := range config.Syscalls { newAction, err := seccomp.ConvertStringToAction(string(call.Action)) if err != nil { return nil, err } newCall := configs.Syscall{ Name: call.Name, Action: newAction, Args: []*configs.Arg{}, } // Loop through all the arguments of the syscall and convert them for _, arg := range call.Args { newOp, err := seccomp.ConvertStringToOperator(string(arg.Op)) if err != nil { return nil, err } newArg := configs.Arg{ Index: arg.Index, Value: arg.Value, ValueTwo: arg.ValueTwo, Op: newOp, } newCall.Args = append(newCall.Args, &newArg) } newConfig.Syscalls = append(newConfig.Syscalls, &newCall) } return newConfig, nil } func createHooks(rspec *specs.LinuxSpec, config *configs.Config) { config.Hooks = &configs.Hooks{} for _, h := range rspec.Hooks.Prestart { cmd := configs.Command{ Path: h.Path, Args: h.Args, Env: h.Env, } config.Hooks.Prestart = append(config.Hooks.Prestart, configs.NewCommandHook(cmd)) } for _, h := range rspec.Hooks.Poststart { cmd := configs.Command{ Path: h.Path, Args: h.Args, Env: h.Env, } config.Hooks.Poststart = append(config.Hooks.Poststart, configs.NewCommandHook(cmd)) } for _, h := range rspec.Hooks.Poststop { cmd := configs.Command{ Path: h.Path, Args: h.Args, Env: h.Env, } config.Hooks.Poststop = append(config.Hooks.Poststop, configs.NewCommandHook(cmd)) } }