1 files changed, 413 insertions, 0 deletions
diff --git a/pkg/proc/init.go b/pkg/proc/init.go
new file mode 100644
index 000000000..8ed48b60b
--- /dev/null
+++ b/pkg/proc/init.go
@@ -0,0 +1,413 @@
+/*
+Copyright The containerd Authors.
+Copyright 2018 Google LLC
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    https://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package proc
+
+import (
+	"context"
+	"encoding/json"
+	"io"
+	"path/filepath"
+	"strings"
+	"sync"
+	"syscall"
+	"time"
+
+	"github.com/containerd/console"
+	"github.com/containerd/containerd/errdefs"
+	"github.com/containerd/containerd/log"
+	"github.com/containerd/containerd/mount"
+	"github.com/containerd/containerd/runtime/proc"
+	"github.com/containerd/fifo"
+	runc "github.com/containerd/go-runc"
+	specs "github.com/opencontainers/runtime-spec/specs-go"
+	"github.com/pkg/errors"
+
+	runsc "github.com/google/gvisor-containerd-shim/pkg/go-runsc"
+)
+
+// InitPidFile name of the file that contains the init pid
+const InitPidFile = "init.pid"
+
+// Init represents an initial process for a container
+type Init struct {
+	wg sync.WaitGroup
+	initState
+
+	// mu is used to ensure that `Start()` and `Exited()` calls return in
+	// the right order when invoked in separate go routines.
+	// This is the case within the shim implementation as it makes use of
+	// the reaper interface.
+	mu sync.Mutex
+
+	waitBlock chan struct{}
+
+	WorkDir string
+
+	id       string
+	Bundle   string
+	console  console.Console
+	Platform proc.Platform
+	io       runc.IO
+	runtime  *runsc.Runsc
+	status   int
+	exited   time.Time
+	pid      int
+	closers  []io.Closer
+	stdin    io.Closer
+	stdio    proc.Stdio
+	Rootfs   string
+	IoUID    int
+	IoGID    int
+	Sandbox  bool
+	UserLog  string
+}
+
+// NewRunsc returns a new runsc instance for a process
+func NewRunsc(root, path, namespace, runtime string, config map[string]string) *runsc.Runsc {
+	if root == "" {
+		root = RunscRoot
+	}
+	return &runsc.Runsc{
+		Command:      runtime,
+		PdeathSignal: syscall.SIGKILL,
+		Log:          filepath.Join(path, "log.json"),
+		LogFormat:    runc.JSON,
+		Root:         filepath.Join(root, namespace),
+		Config:       config,
+	}
+}
+
+// New returns a new init process
+func New(id string, runtime *runsc.Runsc, stdio proc.Stdio) *Init {
+	p := &Init{
+		id:        id,
+		runtime:   runtime,
+		stdio:     stdio,
+		status:    0,
+		waitBlock: make(chan struct{}),
+	}
+	p.initState = &createdState{p: p}
+	return p
+}
+
+// Create the process with the provided config
+func (p *Init) Create(ctx context.Context, r *CreateConfig) error {
+	var (
+		err    error
+		socket *runc.Socket
+	)
+	if r.Terminal {
+		if socket, err = runc.NewTempConsoleSocket(); err != nil {
+			return errors.Wrap(err, "failed to create OCI runtime console socket")
+		}
+		defer socket.Close()
+	} else if hasNoIO(r) {
+		if p.io, err = runc.NewNullIO(); err != nil {
+			return errors.Wrap(err, "creating new NULL IO")
+		}
+	} else {
+		if p.io, err = runc.NewPipeIO(p.IoUID, p.IoGID, withConditionalIO(p.stdio)); err != nil {
+			return errors.Wrap(err, "failed to create OCI runtime io pipes")
+		}
+	}
+	pidFile := filepath.Join(p.Bundle, InitPidFile)
+	opts := &runsc.CreateOpts{
+		PidFile: pidFile,
+	}
+	if socket != nil {
+		opts.ConsoleSocket = socket
+	}
+	if p.Sandbox {
+		opts.IO = p.io
+		// UserLog is only useful for sandbox.
+		opts.UserLog = p.UserLog
+	}
+	if err := p.runtime.Create(ctx, r.ID, r.Bundle, opts); err != nil {
+		return p.runtimeError(err, "OCI runtime create failed")
+	}
+	if r.Stdin != "" {
+		sc, err := fifo.OpenFifo(ctx, r.Stdin, syscall.O_WRONLY|syscall.O_NONBLOCK, 0)
+		if err != nil {
+			return errors.Wrapf(err, "failed to open stdin fifo %s", r.Stdin)
+		}
+		p.stdin = sc
+		p.closers = append(p.closers, sc)
+	}
+	var copyWaitGroup sync.WaitGroup
+	if socket != nil {
+		console, err := socket.ReceiveMaster()
+		if err != nil {
+			return errors.Wrap(err, "failed to retrieve console master")
+		}
+		console, err = p.Platform.CopyConsole(ctx, console, r.Stdin, r.Stdout, r.Stderr, &p.wg, &copyWaitGroup)
+		if err != nil {
+			return errors.Wrap(err, "failed to start console copy")
+		}
+		p.console = console
+	} else if !hasNoIO(r) {
+		if err := copyPipes(ctx, p.io, r.Stdin, r.Stdout, r.Stderr, &p.wg, &copyWaitGroup); err != nil {
+			return errors.Wrap(err, "failed to start io pipe copy")
+		}
+	}
+
+	copyWaitGroup.Wait()
+	pid, err := runc.ReadPidFile(pidFile)
+	if err != nil {
+		return errors.Wrap(err, "failed to retrieve OCI runtime container pid")
+	}
+	p.pid = pid
+	return nil
+}
+
+// Wait for the process to exit
+func (p *Init) Wait() {
+	<-p.waitBlock
+}
+
+// ID of the process
+func (p *Init) ID() string {
+	return p.id
+}
+
+// Pid of the process
+func (p *Init) Pid() int {
+	return p.pid
+}
+
+// ExitStatus of the process
+func (p *Init) ExitStatus() int {
+	p.mu.Lock()
+	defer p.mu.Unlock()
+	return p.status
+}
+
+// ExitedAt at time when the process exited
+func (p *Init) ExitedAt() time.Time {
+	p.mu.Lock()
+	defer p.mu.Unlock()
+	return p.exited
+}
+
+// Status of the process
+func (p *Init) Status(ctx context.Context) (string, error) {
+	p.mu.Lock()
+	defer p.mu.Unlock()
+	c, err := p.runtime.State(ctx, p.id)
+	if err != nil {
+		if strings.Contains(err.Error(), "does not exist") {
+			return "stopped", nil
+		}
+		return "", p.runtimeError(err, "OCI runtime state failed")
+	}
+	return p.convertStatus(c.Status), nil
+}
+
+func (p *Init) start(context context.Context) error {
+	var cio runc.IO
+	if !p.Sandbox {
+		cio = p.io
+	}
+	if err := p.runtime.Start(context, p.id, cio); err != nil {
+		return p.runtimeError(err, "OCI runtime start failed")
+	}
+	go func() {
+		status, err := p.runtime.Wait(context, p.id)
+		if err != nil {
+			log.G(context).WithError(err).Errorf("Failed to wait for container %q", p.id)
+			// TODO(random-liu): Handle runsc kill error.
+			if err := p.killAll(context); err != nil {
+				log.G(context).WithError(err).Errorf("Failed to kill container %q", p.id)
+			}
+			status = internalErrorCode
+		}
+		ExitCh <- Exit{
+			Timestamp: time.Now(),
+			ID:        p.id,
+			Status:    status,
+		}
+	}()
+	return nil
+}
+
+func (p *Init) setExited(status int) {
+	p.exited = time.Now()
+	p.status = status
+	p.Platform.ShutdownConsole(context.Background(), p.console)
+	close(p.waitBlock)
+}
+
+func (p *Init) delete(context context.Context) error {
+	p.killAll(context)
+	p.wg.Wait()
+	err := p.runtime.Delete(context, p.id, nil)
+	// ignore errors if a runtime has already deleted the process
+	// but we still hold metadata and pipes
+	//
+	// this is common during a checkpoint, runc will delete the container state
+	// after a checkpoint and the container will no longer exist within runc
+	if err != nil {
+		if strings.Contains(err.Error(), "does not exist") {
+			err = nil
+		} else {
+			err = p.runtimeError(err, "failed to delete task")
+		}
+	}
+	if p.io != nil {
+		for _, c := range p.closers {
+			c.Close()
+		}
+		p.io.Close()
+	}
+	if err2 := mount.UnmountAll(p.Rootfs, 0); err2 != nil {
+		log.G(context).WithError(err2).Warn("failed to cleanup rootfs mount")
+		if err == nil {
+			err = errors.Wrap(err2, "failed rootfs umount")
+		}
+	}
+	return err
+}
+
+func (p *Init) resize(ws console.WinSize) error {
+	if p.console == nil {
+		return nil
+	}
+	return p.console.Resize(ws)
+}
+
+func (p *Init) kill(context context.Context, signal uint32, all bool) error {
+	var (
+		killErr error
+		backoff = 100 * time.Millisecond
+	)
+	timeout := 1 * time.Second
+	for start := time.Now(); time.Now().Sub(start) < timeout; {
+		c, err := p.runtime.State(context, p.id)
+		if err != nil {
+			if strings.Contains(err.Error(), "does not exist") {
+				return errors.Wrapf(errdefs.ErrNotFound, "no such process")
+			}
+			return p.runtimeError(err, "OCI runtime state failed")
+		}
+		// For runsc, signal only works when container is running state.
+		// If the container is not in running state, directly return
+		// "no such process"
+		if p.convertStatus(c.Status) == "stopped" {
+			return errors.Wrapf(errdefs.ErrNotFound, "no such process")
+		}
+		killErr = p.runtime.Kill(context, p.id, int(signal), &runsc.KillOpts{
+			All: all,
+		})
+		if killErr == nil {
+			return nil
+		}
+		time.Sleep(backoff)
+		backoff *= 2
+	}
+	return p.runtimeError(killErr, "kill timeout")
+}
+
+// KillAll processes belonging to the init process
+func (p *Init) KillAll(context context.Context) error {
+	p.mu.Lock()
+	defer p.mu.Unlock()
+	return p.killAll(context)
+}
+
+func (p *Init) killAll(context context.Context) error {
+	p.runtime.Kill(context, p.id, int(syscall.SIGKILL), &runsc.KillOpts{
+		All: true,
+	})
+	// Ignore error handling for `runsc kill --all` for now.
+	// * If it doesn't return error, it is good;
+	// * If it returns error, consider the container has already stopped.
+	// TODO: Fix `runsc kill --all` error handling.
+	return nil
+}
+
+// Stdin of the process
+func (p *Init) Stdin() io.Closer {
+	return p.stdin
+}
+
+// Runtime returns the OCI runtime configured for the init process
+func (p *Init) Runtime() *runsc.Runsc {
+	return p.runtime
+}
+
+// exec returns a new exec'd process
+func (p *Init) exec(context context.Context, path string, r *ExecConfig) (proc.Process, error) {
+	// process exec request
+	var spec specs.Process
+	if err := json.Unmarshal(r.Spec.Value, &spec); err != nil {
+		return nil, err
+	}
+	spec.Terminal = r.Terminal
+
+	e := &execProcess{
+		id:     r.ID,
+		path:   path,
+		parent: p,
+		spec:   spec,
+		stdio: proc.Stdio{
+			Stdin:    r.Stdin,
+			Stdout:   r.Stdout,
+			Stderr:   r.Stderr,
+			Terminal: r.Terminal,
+		},
+		waitBlock: make(chan struct{}),
+	}
+	e.State = &execCreatedState{p: e}
+	return e, nil
+}
+
+// Stdio of the process
+func (p *Init) Stdio() proc.Stdio {
+	return p.stdio
+}
+
+func (p *Init) runtimeError(rErr error, msg string) error {
+	if rErr == nil {
+		return nil
+	}
+
+	rMsg, err := getLastRuntimeError(p.runtime)
+	switch {
+	case err != nil:
+		return errors.Wrapf(rErr, "%s: %s (%s)", msg, "unable to retrieve OCI runtime error", err.Error())
+	case rMsg == "":
+		return errors.Wrap(rErr, msg)
+	default:
+		return errors.Errorf("%s: %s", msg, rMsg)
+	}
+}
+
+func (p *Init) convertStatus(status string) string {
+	if status == "created" && !p.Sandbox && p.status == internalErrorCode {
+		// Treat start failure state for non-root container as stopped.
+		return "stopped"
+	}
+	return status
+}
+
+func withConditionalIO(c proc.Stdio) runc.IOOpt {
+	return func(o *runc.IOOption) {
+		o.OpenStdin = c.Stdin != ""
+		o.OpenStdout = c.Stdout != ""
+		o.OpenStderr = c.Stderr != ""
+	}
+}