diff options
Diffstat (limited to 'vendor/github.com/opencontainers/runc/libcontainer/factory_linux.go')
-rw-r--r-- | vendor/github.com/opencontainers/runc/libcontainer/factory_linux.go | 325 |
1 files changed, 325 insertions, 0 deletions
diff --git a/vendor/github.com/opencontainers/runc/libcontainer/factory_linux.go b/vendor/github.com/opencontainers/runc/libcontainer/factory_linux.go new file mode 100644 index 000000000..42b6f5a05 --- /dev/null +++ b/vendor/github.com/opencontainers/runc/libcontainer/factory_linux.go @@ -0,0 +1,325 @@ +// +build linux + +package libcontainer + +import ( + "encoding/json" + "fmt" + "os" + "path/filepath" + "regexp" + "runtime/debug" + "strconv" + + "github.com/docker/docker/pkg/mount" + "github.com/opencontainers/runc/libcontainer/cgroups" + "github.com/opencontainers/runc/libcontainer/cgroups/fs" + "github.com/opencontainers/runc/libcontainer/cgroups/rootless" + "github.com/opencontainers/runc/libcontainer/cgroups/systemd" + "github.com/opencontainers/runc/libcontainer/configs" + "github.com/opencontainers/runc/libcontainer/configs/validate" + "github.com/opencontainers/runc/libcontainer/utils" + + "golang.org/x/sys/unix" +) + +const ( + stateFilename = "state.json" + execFifoFilename = "exec.fifo" +) + +var idRegex = regexp.MustCompile(`^[\w+-\.]+$`) + +// InitArgs returns an options func to configure a LinuxFactory with the +// provided init binary path and arguments. +func InitArgs(args ...string) func(*LinuxFactory) error { + return func(l *LinuxFactory) (err error) { + if len(args) > 0 { + // Resolve relative paths to ensure that its available + // after directory changes. + if args[0], err = filepath.Abs(args[0]); err != nil { + return newGenericError(err, ConfigInvalid) + } + } + + l.InitArgs = args + return nil + } +} + +// SystemdCgroups is an options func to configure a LinuxFactory to return +// containers that use systemd to create and manage cgroups. +func SystemdCgroups(l *LinuxFactory) error { + l.NewCgroupsManager = func(config *configs.Cgroup, paths map[string]string) cgroups.Manager { + return &systemd.Manager{ + Cgroups: config, + Paths: paths, + } + } + return nil +} + +// Cgroupfs is an options func to configure a LinuxFactory to return +// containers that use the native cgroups filesystem implementation to +// create and manage cgroups. +func Cgroupfs(l *LinuxFactory) error { + l.NewCgroupsManager = func(config *configs.Cgroup, paths map[string]string) cgroups.Manager { + return &fs.Manager{ + Cgroups: config, + Paths: paths, + } + } + return nil +} + +// RootlessCgroups is an options func to configure a LinuxFactory to +// return containers that use the "rootless" cgroup manager, which will +// fail to do any operations not possible to do with an unprivileged user. +// It should only be used in conjunction with rootless containers. +func RootlessCgroups(l *LinuxFactory) error { + l.NewCgroupsManager = func(config *configs.Cgroup, paths map[string]string) cgroups.Manager { + return &rootless.Manager{ + Cgroups: config, + Paths: paths, + } + } + return nil +} + +// TmpfsRoot is an option func to mount LinuxFactory.Root to tmpfs. +func TmpfsRoot(l *LinuxFactory) error { + mounted, err := mount.Mounted(l.Root) + if err != nil { + return err + } + if !mounted { + if err := unix.Mount("tmpfs", l.Root, "tmpfs", 0, ""); err != nil { + return err + } + } + return nil +} + +// CriuPath returns an option func to configure a LinuxFactory with the +// provided criupath +func CriuPath(criupath string) func(*LinuxFactory) error { + return func(l *LinuxFactory) error { + l.CriuPath = criupath + return nil + } +} + +// New returns a linux based container factory based in the root directory and +// configures the factory with the provided option funcs. +func New(root string, options ...func(*LinuxFactory) error) (Factory, error) { + if root != "" { + if err := os.MkdirAll(root, 0700); err != nil { + return nil, newGenericError(err, SystemError) + } + } + l := &LinuxFactory{ + Root: root, + InitArgs: []string{"/proc/self/exe", "init"}, + Validator: validate.New(), + CriuPath: "criu", + } + Cgroupfs(l) + for _, opt := range options { + if err := opt(l); err != nil { + return nil, err + } + } + return l, nil +} + +// LinuxFactory implements the default factory interface for linux based systems. +type LinuxFactory struct { + // Root directory for the factory to store state. + Root string + + // InitArgs are arguments for calling the init responsibilities for spawning + // a container. + InitArgs []string + + // CriuPath is the path to the criu binary used for checkpoint and restore of + // containers. + CriuPath string + + // Validator provides validation to container configurations. + Validator validate.Validator + + // NewCgroupsManager returns an initialized cgroups manager for a single container. + NewCgroupsManager func(config *configs.Cgroup, paths map[string]string) cgroups.Manager +} + +func (l *LinuxFactory) Create(id string, config *configs.Config) (Container, error) { + if l.Root == "" { + return nil, newGenericError(fmt.Errorf("invalid root"), ConfigInvalid) + } + if err := l.validateID(id); err != nil { + return nil, err + } + if err := l.Validator.Validate(config); err != nil { + return nil, newGenericError(err, ConfigInvalid) + } + containerRoot := filepath.Join(l.Root, id) + if _, err := os.Stat(containerRoot); err == nil { + return nil, newGenericError(fmt.Errorf("container with id exists: %v", id), IdInUse) + } else if !os.IsNotExist(err) { + return nil, newGenericError(err, SystemError) + } + if err := os.MkdirAll(containerRoot, 0711); err != nil { + return nil, newGenericError(err, SystemError) + } + if err := os.Chown(containerRoot, unix.Geteuid(), unix.Getegid()); err != nil { + return nil, newGenericError(err, SystemError) + } + if config.Rootless { + RootlessCgroups(l) + } + c := &linuxContainer{ + id: id, + root: containerRoot, + config: config, + initArgs: l.InitArgs, + criuPath: l.CriuPath, + cgroupManager: l.NewCgroupsManager(config.Cgroups, nil), + } + c.state = &stoppedState{c: c} + return c, nil +} + +func (l *LinuxFactory) Load(id string) (Container, error) { + if l.Root == "" { + return nil, newGenericError(fmt.Errorf("invalid root"), ConfigInvalid) + } + containerRoot := filepath.Join(l.Root, id) + state, err := l.loadState(containerRoot, id) + if err != nil { + return nil, err + } + r := &nonChildProcess{ + processPid: state.InitProcessPid, + processStartTime: state.InitProcessStartTime, + fds: state.ExternalDescriptors, + } + // We have to use the RootlessManager. + if state.Rootless { + RootlessCgroups(l) + } + c := &linuxContainer{ + initProcess: r, + initProcessStartTime: state.InitProcessStartTime, + id: id, + config: &state.Config, + initArgs: l.InitArgs, + criuPath: l.CriuPath, + cgroupManager: l.NewCgroupsManager(state.Config.Cgroups, state.CgroupPaths), + root: containerRoot, + created: state.Created, + } + c.state = &loadedState{c: c} + if err := c.refreshState(); err != nil { + return nil, err + } + return c, nil +} + +func (l *LinuxFactory) Type() string { + return "libcontainer" +} + +// StartInitialization loads a container by opening the pipe fd from the parent to read the configuration and state +// This is a low level implementation detail of the reexec and should not be consumed externally +func (l *LinuxFactory) StartInitialization() (err error) { + var ( + pipefd, rootfd int + consoleSocket *os.File + envInitPipe = os.Getenv("_LIBCONTAINER_INITPIPE") + envStateDir = os.Getenv("_LIBCONTAINER_STATEDIR") + envConsole = os.Getenv("_LIBCONTAINER_CONSOLE") + ) + + // Get the INITPIPE. + pipefd, err = strconv.Atoi(envInitPipe) + if err != nil { + return fmt.Errorf("unable to convert _LIBCONTAINER_INITPIPE=%s to int: %s", envInitPipe, err) + } + + var ( + pipe = os.NewFile(uintptr(pipefd), "pipe") + it = initType(os.Getenv("_LIBCONTAINER_INITTYPE")) + ) + defer pipe.Close() + + // Only init processes have STATEDIR. + rootfd = -1 + if it == initStandard { + if rootfd, err = strconv.Atoi(envStateDir); err != nil { + return fmt.Errorf("unable to convert _LIBCONTAINER_STATEDIR=%s to int: %s", envStateDir, err) + } + } + + if envConsole != "" { + console, err := strconv.Atoi(envConsole) + if err != nil { + return fmt.Errorf("unable to convert _LIBCONTAINER_CONSOLE=%s to int: %s", envConsole, err) + } + consoleSocket = os.NewFile(uintptr(console), "console-socket") + defer consoleSocket.Close() + } + + // clear the current process's environment to clean any libcontainer + // specific env vars. + os.Clearenv() + + defer func() { + // We have an error during the initialization of the container's init, + // send it back to the parent process in the form of an initError. + if werr := utils.WriteJSON(pipe, syncT{procError}); werr != nil { + fmt.Fprintln(os.Stderr, err) + return + } + if werr := utils.WriteJSON(pipe, newSystemError(err)); werr != nil { + fmt.Fprintln(os.Stderr, err) + return + } + }() + defer func() { + if e := recover(); e != nil { + err = fmt.Errorf("panic from initialization: %v, %v", e, string(debug.Stack())) + } + }() + + i, err := newContainerInit(it, pipe, consoleSocket, rootfd) + if err != nil { + return err + } + + // If Init succeeds, syscall.Exec will not return, hence none of the defers will be called. + return i.Init() +} + +func (l *LinuxFactory) loadState(root, id string) (*State, error) { + f, err := os.Open(filepath.Join(root, stateFilename)) + if err != nil { + if os.IsNotExist(err) { + return nil, newGenericError(fmt.Errorf("container %q does not exist", id), ContainerNotExists) + } + return nil, newGenericError(err, SystemError) + } + defer f.Close() + var state *State + if err := json.NewDecoder(f).Decode(&state); err != nil { + return nil, newGenericError(err, SystemError) + } + return state, nil +} + +func (l *LinuxFactory) validateID(id string) error { + if !idRegex.MatchString(id) { + return newGenericError(fmt.Errorf("invalid id format: %v", id), InvalidIdFormat) + } + + return nil +} |