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authorIan Lewis <ianmlewis@gmail.com>2020-08-17 21:44:31 -0400
committerIan Lewis <ianmlewis@gmail.com>2020-08-17 21:44:31 -0400
commitac324f646ee3cb7955b0b45a7453aeb9671cbdf1 (patch)
tree0cbc5018e8807421d701d190dc20525726c7ca76 /pkg/shim/v1/proc
parent352ae1022ce19de28fc72e034cc469872ad79d06 (diff)
parent6d0c5803d557d453f15ac6f683697eeb46dab680 (diff)
Merge branch 'master' into ip-forwarding
- Merges aleksej-paschenko's with HEAD - Adds vfs2 support for ip_forward
Diffstat (limited to 'pkg/shim/v1/proc')
-rw-r--r--pkg/shim/v1/proc/BUILD36
-rw-r--r--pkg/shim/v1/proc/deleted_state.go49
-rw-r--r--pkg/shim/v1/proc/exec.go281
-rw-r--r--pkg/shim/v1/proc/exec_state.go154
-rw-r--r--pkg/shim/v1/proc/init.go460
-rw-r--r--pkg/shim/v1/proc/init_state.go182
-rw-r--r--pkg/shim/v1/proc/io.go162
-rw-r--r--pkg/shim/v1/proc/process.go37
-rw-r--r--pkg/shim/v1/proc/types.go69
-rw-r--r--pkg/shim/v1/proc/utils.go90
10 files changed, 1520 insertions, 0 deletions
diff --git a/pkg/shim/v1/proc/BUILD b/pkg/shim/v1/proc/BUILD
new file mode 100644
index 000000000..4377306af
--- /dev/null
+++ b/pkg/shim/v1/proc/BUILD
@@ -0,0 +1,36 @@
+load("//tools:defs.bzl", "go_library")
+
+package(licenses = ["notice"])
+
+go_library(
+ name = "proc",
+ srcs = [
+ "deleted_state.go",
+ "exec.go",
+ "exec_state.go",
+ "init.go",
+ "init_state.go",
+ "io.go",
+ "process.go",
+ "types.go",
+ "utils.go",
+ ],
+ visibility = [
+ "//pkg/shim:__subpackages__",
+ "//shim:__subpackages__",
+ ],
+ deps = [
+ "//pkg/shim/runsc",
+ "@com_github_containerd_console//:go_default_library",
+ "@com_github_containerd_containerd//errdefs:go_default_library",
+ "@com_github_containerd_containerd//log:go_default_library",
+ "@com_github_containerd_containerd//mount:go_default_library",
+ "@com_github_containerd_containerd//pkg/process:go_default_library",
+ "@com_github_containerd_containerd//pkg/stdio:go_default_library",
+ "@com_github_containerd_fifo//:go_default_library",
+ "@com_github_containerd_go_runc//:go_default_library",
+ "@com_github_gogo_protobuf//types:go_default_library",
+ "@com_github_opencontainers_runtime_spec//specs-go:go_default_library",
+ "@org_golang_x_sys//unix:go_default_library",
+ ],
+)
diff --git a/pkg/shim/v1/proc/deleted_state.go b/pkg/shim/v1/proc/deleted_state.go
new file mode 100644
index 000000000..d9b970c4d
--- /dev/null
+++ b/pkg/shim/v1/proc/deleted_state.go
@@ -0,0 +1,49 @@
+// Copyright 2018 The containerd Authors.
+// Copyright 2018 The gVisor Authors.
+//
+// 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"
+ "fmt"
+
+ "github.com/containerd/console"
+ "github.com/containerd/containerd/errdefs"
+ "github.com/containerd/containerd/pkg/process"
+)
+
+type deletedState struct{}
+
+func (*deletedState) Resize(ws console.WinSize) error {
+ return fmt.Errorf("cannot resize a deleted process.ss")
+}
+
+func (*deletedState) Start(ctx context.Context) error {
+ return fmt.Errorf("cannot start a deleted process.ss")
+}
+
+func (*deletedState) Delete(ctx context.Context) error {
+ return fmt.Errorf("cannot delete a deleted process.ss: %w", errdefs.ErrNotFound)
+}
+
+func (*deletedState) Kill(ctx context.Context, sig uint32, all bool) error {
+ return fmt.Errorf("cannot kill a deleted process.ss: %w", errdefs.ErrNotFound)
+}
+
+func (*deletedState) SetExited(status int) {}
+
+func (*deletedState) Exec(ctx context.Context, path string, r *ExecConfig) (process.Process, error) {
+ return nil, fmt.Errorf("cannot exec in a deleted state")
+}
diff --git a/pkg/shim/v1/proc/exec.go b/pkg/shim/v1/proc/exec.go
new file mode 100644
index 000000000..1d1d90488
--- /dev/null
+++ b/pkg/shim/v1/proc/exec.go
@@ -0,0 +1,281 @@
+// Copyright 2018 The containerd Authors.
+// Copyright 2018 The gVisor Authors.
+//
+// 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"
+ "fmt"
+ "io"
+ "os"
+ "path/filepath"
+ "sync"
+ "syscall"
+ "time"
+
+ "github.com/containerd/console"
+ "github.com/containerd/containerd/errdefs"
+ "github.com/containerd/containerd/pkg/stdio"
+ "github.com/containerd/fifo"
+ runc "github.com/containerd/go-runc"
+ specs "github.com/opencontainers/runtime-spec/specs-go"
+ "golang.org/x/sys/unix"
+
+ "gvisor.dev/gvisor/pkg/shim/runsc"
+)
+
+type execProcess struct {
+ wg sync.WaitGroup
+
+ execState execState
+
+ mu sync.Mutex
+ id string
+ console console.Console
+ io runc.IO
+ status int
+ exited time.Time
+ pid int
+ internalPid int
+ closers []io.Closer
+ stdin io.Closer
+ stdio stdio.Stdio
+ path string
+ spec specs.Process
+
+ parent *Init
+ waitBlock chan struct{}
+}
+
+func (e *execProcess) Wait() {
+ <-e.waitBlock
+}
+
+func (e *execProcess) ID() string {
+ return e.id
+}
+
+func (e *execProcess) Pid() int {
+ e.mu.Lock()
+ defer e.mu.Unlock()
+ return e.pid
+}
+
+func (e *execProcess) ExitStatus() int {
+ e.mu.Lock()
+ defer e.mu.Unlock()
+ return e.status
+}
+
+func (e *execProcess) ExitedAt() time.Time {
+ e.mu.Lock()
+ defer e.mu.Unlock()
+ return e.exited
+}
+
+func (e *execProcess) SetExited(status int) {
+ e.mu.Lock()
+ defer e.mu.Unlock()
+
+ e.execState.SetExited(status)
+}
+
+func (e *execProcess) setExited(status int) {
+ e.status = status
+ e.exited = time.Now()
+ e.parent.Platform.ShutdownConsole(context.Background(), e.console)
+ close(e.waitBlock)
+}
+
+func (e *execProcess) Delete(ctx context.Context) error {
+ e.mu.Lock()
+ defer e.mu.Unlock()
+
+ return e.execState.Delete(ctx)
+}
+
+func (e *execProcess) delete(ctx context.Context) error {
+ e.wg.Wait()
+ if e.io != nil {
+ for _, c := range e.closers {
+ c.Close()
+ }
+ e.io.Close()
+ }
+ pidfile := filepath.Join(e.path, fmt.Sprintf("%s.pid", e.id))
+ // silently ignore error
+ os.Remove(pidfile)
+ internalPidfile := filepath.Join(e.path, fmt.Sprintf("%s-internal.pid", e.id))
+ // silently ignore error
+ os.Remove(internalPidfile)
+ return nil
+}
+
+func (e *execProcess) Resize(ws console.WinSize) error {
+ e.mu.Lock()
+ defer e.mu.Unlock()
+
+ return e.execState.Resize(ws)
+}
+
+func (e *execProcess) resize(ws console.WinSize) error {
+ if e.console == nil {
+ return nil
+ }
+ return e.console.Resize(ws)
+}
+
+func (e *execProcess) Kill(ctx context.Context, sig uint32, _ bool) error {
+ e.mu.Lock()
+ defer e.mu.Unlock()
+
+ return e.execState.Kill(ctx, sig, false)
+}
+
+func (e *execProcess) kill(ctx context.Context, sig uint32, _ bool) error {
+ internalPid := e.internalPid
+ if internalPid != 0 {
+ if err := e.parent.runtime.Kill(ctx, e.parent.id, int(sig), &runsc.KillOpts{
+ Pid: internalPid,
+ }); err != nil {
+ // If this returns error, consider the process has
+ // already stopped.
+ //
+ // TODO: Fix after signal handling is fixed.
+ return fmt.Errorf("%s: %w", err.Error(), errdefs.ErrNotFound)
+ }
+ }
+ return nil
+}
+
+func (e *execProcess) Stdin() io.Closer {
+ return e.stdin
+}
+
+func (e *execProcess) Stdio() stdio.Stdio {
+ return e.stdio
+}
+
+func (e *execProcess) Start(ctx context.Context) error {
+ e.mu.Lock()
+ defer e.mu.Unlock()
+
+ return e.execState.Start(ctx)
+}
+
+func (e *execProcess) start(ctx context.Context) (err error) {
+ var (
+ socket *runc.Socket
+ pidfile = filepath.Join(e.path, fmt.Sprintf("%s.pid", e.id))
+ internalPidfile = filepath.Join(e.path, fmt.Sprintf("%s-internal.pid", e.id))
+ )
+ if e.stdio.Terminal {
+ if socket, err = runc.NewTempConsoleSocket(); err != nil {
+ return fmt.Errorf("failed to create runc console socket: %w", err)
+ }
+ defer socket.Close()
+ } else if e.stdio.IsNull() {
+ if e.io, err = runc.NewNullIO(); err != nil {
+ return fmt.Errorf("creating new NULL IO: %w", err)
+ }
+ } else {
+ if e.io, err = runc.NewPipeIO(e.parent.IoUID, e.parent.IoGID, withConditionalIO(e.stdio)); err != nil {
+ return fmt.Errorf("failed to create runc io pipes: %w", err)
+ }
+ }
+ opts := &runsc.ExecOpts{
+ PidFile: pidfile,
+ InternalPidFile: internalPidfile,
+ IO: e.io,
+ Detach: true,
+ }
+ if socket != nil {
+ opts.ConsoleSocket = socket
+ }
+ eventCh := e.parent.Monitor.Subscribe()
+ defer func() {
+ // Unsubscribe if an error is returned.
+ if err != nil {
+ e.parent.Monitor.Unsubscribe(eventCh)
+ }
+ }()
+ if err := e.parent.runtime.Exec(ctx, e.parent.id, e.spec, opts); err != nil {
+ close(e.waitBlock)
+ return e.parent.runtimeError(err, "OCI runtime exec failed")
+ }
+ if e.stdio.Stdin != "" {
+ sc, err := fifo.OpenFifo(context.Background(), e.stdio.Stdin, syscall.O_WRONLY|syscall.O_NONBLOCK, 0)
+ if err != nil {
+ return fmt.Errorf("failed to open stdin fifo %s: %w", e.stdio.Stdin, err)
+ }
+ e.closers = append(e.closers, sc)
+ e.stdin = sc
+ }
+ ctx, cancel := context.WithTimeout(ctx, 30*time.Second)
+ defer cancel()
+ if socket != nil {
+ console, err := socket.ReceiveMaster()
+ if err != nil {
+ return fmt.Errorf("failed to retrieve console master: %w", err)
+ }
+ if e.console, err = e.parent.Platform.CopyConsole(ctx, console, e.stdio.Stdin, e.stdio.Stdout, e.stdio.Stderr, &e.wg); err != nil {
+ return fmt.Errorf("failed to start console copy: %w", err)
+ }
+ } else if !e.stdio.IsNull() {
+ if err := copyPipes(ctx, e.io, e.stdio.Stdin, e.stdio.Stdout, e.stdio.Stderr, &e.wg); err != nil {
+ return fmt.Errorf("failed to start io pipe copy: %w", err)
+ }
+ }
+ pid, err := runc.ReadPidFile(opts.PidFile)
+ if err != nil {
+ return fmt.Errorf("failed to retrieve OCI runtime exec pid: %w", err)
+ }
+ e.pid = pid
+ internalPid, err := runc.ReadPidFile(opts.InternalPidFile)
+ if err != nil {
+ return fmt.Errorf("failed to retrieve OCI runtime exec internal pid: %w", err)
+ }
+ e.internalPid = internalPid
+ go func() {
+ defer e.parent.Monitor.Unsubscribe(eventCh)
+ for event := range eventCh {
+ if event.Pid == e.pid {
+ ExitCh <- Exit{
+ Timestamp: event.Timestamp,
+ ID: e.id,
+ Status: event.Status,
+ }
+ break
+ }
+ }
+ }()
+ return nil
+}
+
+func (e *execProcess) Status(ctx context.Context) (string, error) {
+ e.mu.Lock()
+ defer e.mu.Unlock()
+ // if we don't have a pid then the exec process has just been created
+ if e.pid == 0 {
+ return "created", nil
+ }
+ // if we have a pid and it can be signaled, the process is running
+ // TODO(random-liu): Use `runsc kill --pid`.
+ if err := unix.Kill(e.pid, 0); err == nil {
+ return "running", nil
+ }
+ // else if we have a pid but it can nolonger be signaled, it has stopped
+ return "stopped", nil
+}
diff --git a/pkg/shim/v1/proc/exec_state.go b/pkg/shim/v1/proc/exec_state.go
new file mode 100644
index 000000000..4dcda8b44
--- /dev/null
+++ b/pkg/shim/v1/proc/exec_state.go
@@ -0,0 +1,154 @@
+// Copyright 2018 The containerd Authors.
+// Copyright 2018 The gVisor Authors.
+//
+// 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"
+ "fmt"
+
+ "github.com/containerd/console"
+)
+
+type execState interface {
+ Resize(console.WinSize) error
+ Start(context.Context) error
+ Delete(context.Context) error
+ Kill(context.Context, uint32, bool) error
+ SetExited(int)
+}
+
+type execCreatedState struct {
+ p *execProcess
+}
+
+func (s *execCreatedState) transition(name string) error {
+ switch name {
+ case "running":
+ s.p.execState = &execRunningState{p: s.p}
+ case "stopped":
+ s.p.execState = &execStoppedState{p: s.p}
+ case "deleted":
+ s.p.execState = &deletedState{}
+ default:
+ return fmt.Errorf("invalid state transition %q to %q", stateName(s), name)
+ }
+ return nil
+}
+
+func (s *execCreatedState) Resize(ws console.WinSize) error {
+ return s.p.resize(ws)
+}
+
+func (s *execCreatedState) Start(ctx context.Context) error {
+ if err := s.p.start(ctx); err != nil {
+ return err
+ }
+ return s.transition("running")
+}
+
+func (s *execCreatedState) Delete(ctx context.Context) error {
+ if err := s.p.delete(ctx); err != nil {
+ return err
+ }
+ return s.transition("deleted")
+}
+
+func (s *execCreatedState) Kill(ctx context.Context, sig uint32, all bool) error {
+ return s.p.kill(ctx, sig, all)
+}
+
+func (s *execCreatedState) SetExited(status int) {
+ s.p.setExited(status)
+
+ if err := s.transition("stopped"); err != nil {
+ panic(err)
+ }
+}
+
+type execRunningState struct {
+ p *execProcess
+}
+
+func (s *execRunningState) transition(name string) error {
+ switch name {
+ case "stopped":
+ s.p.execState = &execStoppedState{p: s.p}
+ default:
+ return fmt.Errorf("invalid state transition %q to %q", stateName(s), name)
+ }
+ return nil
+}
+
+func (s *execRunningState) Resize(ws console.WinSize) error {
+ return s.p.resize(ws)
+}
+
+func (s *execRunningState) Start(ctx context.Context) error {
+ return fmt.Errorf("cannot start a running process")
+}
+
+func (s *execRunningState) Delete(ctx context.Context) error {
+ return fmt.Errorf("cannot delete a running process")
+}
+
+func (s *execRunningState) Kill(ctx context.Context, sig uint32, all bool) error {
+ return s.p.kill(ctx, sig, all)
+}
+
+func (s *execRunningState) SetExited(status int) {
+ s.p.setExited(status)
+
+ if err := s.transition("stopped"); err != nil {
+ panic(err)
+ }
+}
+
+type execStoppedState struct {
+ p *execProcess
+}
+
+func (s *execStoppedState) transition(name string) error {
+ switch name {
+ case "deleted":
+ s.p.execState = &deletedState{}
+ default:
+ return fmt.Errorf("invalid state transition %q to %q", stateName(s), name)
+ }
+ return nil
+}
+
+func (s *execStoppedState) Resize(ws console.WinSize) error {
+ return fmt.Errorf("cannot resize a stopped container")
+}
+
+func (s *execStoppedState) Start(ctx context.Context) error {
+ return fmt.Errorf("cannot start a stopped process")
+}
+
+func (s *execStoppedState) Delete(ctx context.Context) error {
+ if err := s.p.delete(ctx); err != nil {
+ return err
+ }
+ return s.transition("deleted")
+}
+
+func (s *execStoppedState) Kill(ctx context.Context, sig uint32, all bool) error {
+ return s.p.kill(ctx, sig, all)
+}
+
+func (s *execStoppedState) SetExited(status int) {
+ // no op
+}
diff --git a/pkg/shim/v1/proc/init.go b/pkg/shim/v1/proc/init.go
new file mode 100644
index 000000000..dab3123d6
--- /dev/null
+++ b/pkg/shim/v1/proc/init.go
@@ -0,0 +1,460 @@
+// Copyright 2018 The containerd Authors.
+// Copyright 2018 The gVisor Authors.
+//
+// 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"
+ "fmt"
+ "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/pkg/process"
+ "github.com/containerd/containerd/pkg/stdio"
+ "github.com/containerd/fifo"
+ runc "github.com/containerd/go-runc"
+ specs "github.com/opencontainers/runtime-spec/specs-go"
+
+ "gvisor.dev/gvisor/pkg/shim/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 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 stdio.Platform
+ io runc.IO
+ runtime *runsc.Runsc
+ status int
+ exited time.Time
+ pid int
+ closers []io.Closer
+ stdin io.Closer
+ stdio stdio.Stdio
+ Rootfs string
+ IoUID int
+ IoGID int
+ Sandbox bool
+ UserLog string
+ Monitor ProcessMonitor
+}
+
+// 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 stdio.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) (err error) {
+ var socket *runc.Socket
+ if r.Terminal {
+ if socket, err = runc.NewTempConsoleSocket(); err != nil {
+ return fmt.Errorf("failed to create OCI runtime console socket: %w", err)
+ }
+ defer socket.Close()
+ } else if hasNoIO(r) {
+ if p.io, err = runc.NewNullIO(); err != nil {
+ return fmt.Errorf("creating new NULL IO: %w", err)
+ }
+ } else {
+ if p.io, err = runc.NewPipeIO(p.IoUID, p.IoGID, withConditionalIO(p.stdio)); err != nil {
+ return fmt.Errorf("failed to create OCI runtime io pipes: %w", err)
+ }
+ }
+ 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(context.Background(), r.Stdin, syscall.O_WRONLY|syscall.O_NONBLOCK, 0)
+ if err != nil {
+ return fmt.Errorf("failed to open stdin fifo %s: %w", r.Stdin, err)
+ }
+ p.stdin = sc
+ p.closers = append(p.closers, sc)
+ }
+ ctx, cancel := context.WithTimeout(ctx, 30*time.Second)
+ defer cancel()
+ if socket != nil {
+ console, err := socket.ReceiveMaster()
+ if err != nil {
+ return fmt.Errorf("failed to retrieve console master: %w", err)
+ }
+ console, err = p.Platform.CopyConsole(ctx, console, r.Stdin, r.Stdout, r.Stderr, &p.wg)
+ if err != nil {
+ return fmt.Errorf("failed to start console copy: %w", err)
+ }
+ p.console = console
+ } else if !hasNoIO(r) {
+ if err := copyPipes(ctx, p.io, r.Stdin, r.Stdout, r.Stderr, &p.wg); err != nil {
+ return fmt.Errorf("failed to start io pipe copy: %w", err)
+ }
+ }
+ pid, err := runc.ReadPidFile(pidFile)
+ if err != nil {
+ return fmt.Errorf("failed to retrieve OCI runtime container pid: %w", err)
+ }
+ p.pid = pid
+ return nil
+}
+
+// Wait waits for the process to exit.
+func (p *Init) Wait() {
+ <-p.waitBlock
+}
+
+// ID returns the ID of the process.
+func (p *Init) ID() string {
+ return p.id
+}
+
+// Pid returns the PID of the process.
+func (p *Init) Pid() int {
+ return p.pid
+}
+
+// ExitStatus returns the exit status of the process.
+func (p *Init) ExitStatus() int {
+ p.mu.Lock()
+ defer p.mu.Unlock()
+ return p.status
+}
+
+// ExitedAt returns the time when the process exited.
+func (p *Init) ExitedAt() time.Time {
+ p.mu.Lock()
+ defer p.mu.Unlock()
+ return p.exited
+}
+
+// Status returns the 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
+}
+
+// Start starts the init process.
+func (p *Init) Start(ctx context.Context) error {
+ p.mu.Lock()
+ defer p.mu.Unlock()
+
+ return p.initState.Start(ctx)
+}
+
+func (p *Init) start(ctx context.Context) error {
+ var cio runc.IO
+ if !p.Sandbox {
+ cio = p.io
+ }
+ if err := p.runtime.Start(ctx, p.id, cio); err != nil {
+ return p.runtimeError(err, "OCI runtime start failed")
+ }
+ go func() {
+ status, err := p.runtime.Wait(context.Background(), p.id)
+ if err != nil {
+ log.G(ctx).WithError(err).Errorf("Failed to wait for container %q", p.id)
+ // TODO(random-liu): Handle runsc kill error.
+ if err := p.killAll(ctx); err != nil {
+ log.G(ctx).WithError(err).Errorf("Failed to kill container %q", p.id)
+ }
+ status = internalErrorCode
+ }
+ ExitCh <- Exit{
+ Timestamp: time.Now(),
+ ID: p.id,
+ Status: status,
+ }
+ }()
+ return nil
+}
+
+// SetExited set the exit stauts of the init process.
+func (p *Init) SetExited(status int) {
+ p.mu.Lock()
+ defer p.mu.Unlock()
+
+ p.initState.SetExited(status)
+}
+
+func (p *Init) setExited(status int) {
+ p.exited = time.Now()
+ p.status = status
+ p.Platform.ShutdownConsole(context.Background(), p.console)
+ close(p.waitBlock)
+}
+
+// Delete deletes the init process.
+func (p *Init) Delete(ctx context.Context) error {
+ p.mu.Lock()
+ defer p.mu.Unlock()
+
+ return p.initState.Delete(ctx)
+}
+
+func (p *Init) delete(ctx context.Context) error {
+ p.killAll(ctx)
+ p.wg.Wait()
+ err := p.runtime.Delete(ctx, 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(ctx).WithError(err2).Warn("failed to cleanup rootfs mount")
+ if err == nil {
+ err = fmt.Errorf("failed rootfs umount: %w", err2)
+ }
+ }
+ return err
+}
+
+// Resize resizes the init processes console.
+func (p *Init) Resize(ws console.WinSize) error {
+ p.mu.Lock()
+ defer p.mu.Unlock()
+
+ if p.console == nil {
+ return nil
+ }
+ return p.console.Resize(ws)
+}
+
+func (p *Init) resize(ws console.WinSize) error {
+ if p.console == nil {
+ return nil
+ }
+ return p.console.Resize(ws)
+}
+
+// Kill kills the init process.
+func (p *Init) Kill(ctx context.Context, signal uint32, all bool) error {
+ p.mu.Lock()
+ defer p.mu.Unlock()
+
+ return p.initState.Kill(ctx, signal, all)
+}
+
+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 fmt.Errorf("no such process: %w", errdefs.ErrNotFound)
+ }
+ 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 fmt.Errorf("no such process: %w", errdefs.ErrNotFound)
+ }
+ 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 kills all 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 returns the 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 child process.
+func (p *Init) Exec(ctx context.Context, path string, r *ExecConfig) (process.Process, error) {
+ p.mu.Lock()
+ defer p.mu.Unlock()
+
+ return p.initState.Exec(ctx, path, r)
+}
+
+// exec returns a new exec'd process.
+func (p *Init) exec(ctx context.Context, path string, r *ExecConfig) (process.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: stdio.Stdio{
+ Stdin: r.Stdin,
+ Stdout: r.Stdout,
+ Stderr: r.Stderr,
+ Terminal: r.Terminal,
+ },
+ waitBlock: make(chan struct{}),
+ }
+ e.execState = &execCreatedState{p: e}
+ return e, nil
+}
+
+// Stdio returns the stdio of the process.
+func (p *Init) Stdio() stdio.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 fmt.Errorf("%s: %w (unable to retrieve OCI runtime error: %v)", msg, rErr, err)
+ case rMsg == "":
+ return fmt.Errorf("%s: %w", msg, rErr)
+ default:
+ return fmt.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 stdio.Stdio) runc.IOOpt {
+ return func(o *runc.IOOption) {
+ o.OpenStdin = c.Stdin != ""
+ o.OpenStdout = c.Stdout != ""
+ o.OpenStderr = c.Stderr != ""
+ }
+}
diff --git a/pkg/shim/v1/proc/init_state.go b/pkg/shim/v1/proc/init_state.go
new file mode 100644
index 000000000..9233ecc85
--- /dev/null
+++ b/pkg/shim/v1/proc/init_state.go
@@ -0,0 +1,182 @@
+// Copyright 2018 The containerd Authors.
+// Copyright 2018 The gVisor Authors.
+//
+// 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"
+ "fmt"
+
+ "github.com/containerd/console"
+ "github.com/containerd/containerd/errdefs"
+ "github.com/containerd/containerd/pkg/process"
+)
+
+type initState interface {
+ Resize(console.WinSize) error
+ Start(context.Context) error
+ Delete(context.Context) error
+ Exec(context.Context, string, *ExecConfig) (process.Process, error)
+ Kill(context.Context, uint32, bool) error
+ SetExited(int)
+}
+
+type createdState struct {
+ p *Init
+}
+
+func (s *createdState) transition(name string) error {
+ switch name {
+ case "running":
+ s.p.initState = &runningState{p: s.p}
+ case "stopped":
+ s.p.initState = &stoppedState{p: s.p}
+ case "deleted":
+ s.p.initState = &deletedState{}
+ default:
+ return fmt.Errorf("invalid state transition %q to %q", stateName(s), name)
+ }
+ return nil
+}
+
+func (s *createdState) Resize(ws console.WinSize) error {
+ return s.p.resize(ws)
+}
+
+func (s *createdState) Start(ctx context.Context) error {
+ if err := s.p.start(ctx); err != nil {
+ // Containerd doesn't allow deleting container in created state.
+ // However, for gvisor, a non-root container in created state can
+ // only go to running state. If the container can't be started,
+ // it can only stay in created state, and never be deleted.
+ // To work around that, we treat non-root container in start failure
+ // state as stopped.
+ if !s.p.Sandbox {
+ s.p.io.Close()
+ s.p.setExited(internalErrorCode)
+ if err := s.transition("stopped"); err != nil {
+ panic(err)
+ }
+ }
+ return err
+ }
+ return s.transition("running")
+}
+
+func (s *createdState) Delete(ctx context.Context) error {
+ if err := s.p.delete(ctx); err != nil {
+ return err
+ }
+ return s.transition("deleted")
+}
+
+func (s *createdState) Kill(ctx context.Context, sig uint32, all bool) error {
+ return s.p.kill(ctx, sig, all)
+}
+
+func (s *createdState) SetExited(status int) {
+ s.p.setExited(status)
+
+ if err := s.transition("stopped"); err != nil {
+ panic(err)
+ }
+}
+
+func (s *createdState) Exec(ctx context.Context, path string, r *ExecConfig) (process.Process, error) {
+ return s.p.exec(ctx, path, r)
+}
+
+type runningState struct {
+ p *Init
+}
+
+func (s *runningState) transition(name string) error {
+ switch name {
+ case "stopped":
+ s.p.initState = &stoppedState{p: s.p}
+ default:
+ return fmt.Errorf("invalid state transition %q to %q", stateName(s), name)
+ }
+ return nil
+}
+
+func (s *runningState) Resize(ws console.WinSize) error {
+ return s.p.resize(ws)
+}
+
+func (s *runningState) Start(ctx context.Context) error {
+ return fmt.Errorf("cannot start a running process.ss")
+}
+
+func (s *runningState) Delete(ctx context.Context) error {
+ return fmt.Errorf("cannot delete a running process.ss")
+}
+
+func (s *runningState) Kill(ctx context.Context, sig uint32, all bool) error {
+ return s.p.kill(ctx, sig, all)
+}
+
+func (s *runningState) SetExited(status int) {
+ s.p.setExited(status)
+
+ if err := s.transition("stopped"); err != nil {
+ panic(err)
+ }
+}
+
+func (s *runningState) Exec(ctx context.Context, path string, r *ExecConfig) (process.Process, error) {
+ return s.p.exec(ctx, path, r)
+}
+
+type stoppedState struct {
+ p *Init
+}
+
+func (s *stoppedState) transition(name string) error {
+ switch name {
+ case "deleted":
+ s.p.initState = &deletedState{}
+ default:
+ return fmt.Errorf("invalid state transition %q to %q", stateName(s), name)
+ }
+ return nil
+}
+
+func (s *stoppedState) Resize(ws console.WinSize) error {
+ return fmt.Errorf("cannot resize a stopped container")
+}
+
+func (s *stoppedState) Start(ctx context.Context) error {
+ return fmt.Errorf("cannot start a stopped process.ss")
+}
+
+func (s *stoppedState) Delete(ctx context.Context) error {
+ if err := s.p.delete(ctx); err != nil {
+ return err
+ }
+ return s.transition("deleted")
+}
+
+func (s *stoppedState) Kill(ctx context.Context, sig uint32, all bool) error {
+ return errdefs.ToGRPCf(errdefs.ErrNotFound, "process.ss %s not found", s.p.id)
+}
+
+func (s *stoppedState) SetExited(status int) {
+ // no op
+}
+
+func (s *stoppedState) Exec(ctx context.Context, path string, r *ExecConfig) (process.Process, error) {
+ return nil, fmt.Errorf("cannot exec in a stopped state")
+}
diff --git a/pkg/shim/v1/proc/io.go b/pkg/shim/v1/proc/io.go
new file mode 100644
index 000000000..34d825fb7
--- /dev/null
+++ b/pkg/shim/v1/proc/io.go
@@ -0,0 +1,162 @@
+// Copyright 2018 The containerd Authors.
+// Copyright 2018 The gVisor Authors.
+//
+// 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"
+ "fmt"
+ "io"
+ "os"
+ "sync"
+ "sync/atomic"
+ "syscall"
+
+ "github.com/containerd/containerd/log"
+ "github.com/containerd/fifo"
+ runc "github.com/containerd/go-runc"
+)
+
+// TODO(random-liu): This file can be a util.
+
+var bufPool = sync.Pool{
+ New: func() interface{} {
+ buffer := make([]byte, 32<<10)
+ return &buffer
+ },
+}
+
+func copyPipes(ctx context.Context, rio runc.IO, stdin, stdout, stderr string, wg *sync.WaitGroup) error {
+ var sameFile *countingWriteCloser
+ for _, i := range []struct {
+ name string
+ dest func(wc io.WriteCloser, rc io.Closer)
+ }{
+ {
+ name: stdout,
+ dest: func(wc io.WriteCloser, rc io.Closer) {
+ wg.Add(1)
+ go func() {
+ p := bufPool.Get().(*[]byte)
+ defer bufPool.Put(p)
+ if _, err := io.CopyBuffer(wc, rio.Stdout(), *p); err != nil {
+ log.G(ctx).Warn("error copying stdout")
+ }
+ wg.Done()
+ wc.Close()
+ if rc != nil {
+ rc.Close()
+ }
+ }()
+ },
+ }, {
+ name: stderr,
+ dest: func(wc io.WriteCloser, rc io.Closer) {
+ wg.Add(1)
+ go func() {
+ p := bufPool.Get().(*[]byte)
+ defer bufPool.Put(p)
+ if _, err := io.CopyBuffer(wc, rio.Stderr(), *p); err != nil {
+ log.G(ctx).Warn("error copying stderr")
+ }
+ wg.Done()
+ wc.Close()
+ if rc != nil {
+ rc.Close()
+ }
+ }()
+ },
+ },
+ } {
+ ok, err := isFifo(i.name)
+ if err != nil {
+ return err
+ }
+ var (
+ fw io.WriteCloser
+ fr io.Closer
+ )
+ if ok {
+ if fw, err = fifo.OpenFifo(ctx, i.name, syscall.O_WRONLY, 0); err != nil {
+ return fmt.Errorf("gvisor-containerd-shim: opening %s failed: %s", i.name, err)
+ }
+ if fr, err = fifo.OpenFifo(ctx, i.name, syscall.O_RDONLY, 0); err != nil {
+ return fmt.Errorf("gvisor-containerd-shim: opening %s failed: %s", i.name, err)
+ }
+ } else {
+ if sameFile != nil {
+ sameFile.count++
+ i.dest(sameFile, nil)
+ continue
+ }
+ if fw, err = os.OpenFile(i.name, syscall.O_WRONLY|syscall.O_APPEND, 0); err != nil {
+ return fmt.Errorf("gvisor-containerd-shim: opening %s failed: %s", i.name, err)
+ }
+ if stdout == stderr {
+ sameFile = &countingWriteCloser{
+ WriteCloser: fw,
+ count: 1,
+ }
+ }
+ }
+ i.dest(fw, fr)
+ }
+ if stdin == "" {
+ return nil
+ }
+ f, err := fifo.OpenFifo(context.Background(), stdin, syscall.O_RDONLY|syscall.O_NONBLOCK, 0)
+ if err != nil {
+ return fmt.Errorf("gvisor-containerd-shim: opening %s failed: %s", stdin, err)
+ }
+ go func() {
+ p := bufPool.Get().(*[]byte)
+ defer bufPool.Put(p)
+
+ io.CopyBuffer(rio.Stdin(), f, *p)
+ rio.Stdin().Close()
+ f.Close()
+ }()
+ return nil
+}
+
+// countingWriteCloser masks io.Closer() until close has been invoked a certain number of times.
+type countingWriteCloser struct {
+ io.WriteCloser
+ count int64
+}
+
+func (c *countingWriteCloser) Close() error {
+ if atomic.AddInt64(&c.count, -1) > 0 {
+ return nil
+ }
+ return c.WriteCloser.Close()
+}
+
+// isFifo checks if a file is a fifo.
+//
+// If the file does not exist then it returns false.
+func isFifo(path string) (bool, error) {
+ stat, err := os.Stat(path)
+ if err != nil {
+ if os.IsNotExist(err) {
+ return false, nil
+ }
+ return false, err
+ }
+ if stat.Mode()&os.ModeNamedPipe == os.ModeNamedPipe {
+ return true, nil
+ }
+ return false, nil
+}
diff --git a/pkg/shim/v1/proc/process.go b/pkg/shim/v1/proc/process.go
new file mode 100644
index 000000000..d462c3eef
--- /dev/null
+++ b/pkg/shim/v1/proc/process.go
@@ -0,0 +1,37 @@
+// Copyright 2018 The containerd Authors.
+// Copyright 2018 The gVisor Authors.
+//
+// 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 (
+ "fmt"
+)
+
+// RunscRoot is the path to the root runsc state directory.
+const RunscRoot = "/run/containerd/runsc"
+
+func stateName(v interface{}) string {
+ switch v.(type) {
+ case *runningState, *execRunningState:
+ return "running"
+ case *createdState, *execCreatedState:
+ return "created"
+ case *deletedState:
+ return "deleted"
+ case *stoppedState:
+ return "stopped"
+ }
+ panic(fmt.Errorf("invalid state %v", v))
+}
diff --git a/pkg/shim/v1/proc/types.go b/pkg/shim/v1/proc/types.go
new file mode 100644
index 000000000..2b0df4663
--- /dev/null
+++ b/pkg/shim/v1/proc/types.go
@@ -0,0 +1,69 @@
+// Copyright 2018 The containerd Authors.
+// Copyright 2018 The gVisor Authors.
+//
+// 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 (
+ "time"
+
+ runc "github.com/containerd/go-runc"
+ "github.com/gogo/protobuf/types"
+)
+
+// Mount holds filesystem mount configuration.
+type Mount struct {
+ Type string
+ Source string
+ Target string
+ Options []string
+}
+
+// CreateConfig hold task creation configuration.
+type CreateConfig struct {
+ ID string
+ Bundle string
+ Runtime string
+ Rootfs []Mount
+ Terminal bool
+ Stdin string
+ Stdout string
+ Stderr string
+ Options *types.Any
+}
+
+// ExecConfig holds exec creation configuration.
+type ExecConfig struct {
+ ID string
+ Terminal bool
+ Stdin string
+ Stdout string
+ Stderr string
+ Spec *types.Any
+}
+
+// Exit is the type of exit events.
+type Exit struct {
+ Timestamp time.Time
+ ID string
+ Status int
+}
+
+// ProcessMonitor monitors process exit changes.
+type ProcessMonitor interface {
+ // Subscribe to process exit changes
+ Subscribe() chan runc.Exit
+ // Unsubscribe to process exit changes
+ Unsubscribe(c chan runc.Exit)
+}
diff --git a/pkg/shim/v1/proc/utils.go b/pkg/shim/v1/proc/utils.go
new file mode 100644
index 000000000..716de2f59
--- /dev/null
+++ b/pkg/shim/v1/proc/utils.go
@@ -0,0 +1,90 @@
+// Copyright 2018 The containerd Authors.
+// Copyright 2018 The gVisor Authors.
+//
+// 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 (
+ "encoding/json"
+ "io"
+ "os"
+ "strings"
+ "time"
+
+ "gvisor.dev/gvisor/pkg/shim/runsc"
+)
+
+const (
+ internalErrorCode = 128
+ bufferSize = 32
+)
+
+// ExitCh is the exit events channel for containers and exec processes
+// inside the sandbox.
+var ExitCh = make(chan Exit, bufferSize)
+
+// TODO(mlaventure): move to runc package?
+func getLastRuntimeError(r *runsc.Runsc) (string, error) {
+ if r.Log == "" {
+ return "", nil
+ }
+
+ f, err := os.OpenFile(r.Log, os.O_RDONLY, 0400)
+ if err != nil {
+ return "", err
+ }
+
+ var (
+ errMsg string
+ log struct {
+ Level string
+ Msg string
+ Time time.Time
+ }
+ )
+
+ dec := json.NewDecoder(f)
+ for err = nil; err == nil; {
+ if err = dec.Decode(&log); err != nil && err != io.EOF {
+ return "", err
+ }
+ if log.Level == "error" {
+ errMsg = strings.TrimSpace(log.Msg)
+ }
+ }
+
+ return errMsg, nil
+}
+
+func copyFile(to, from string) error {
+ ff, err := os.Open(from)
+ if err != nil {
+ return err
+ }
+ defer ff.Close()
+ tt, err := os.Create(to)
+ if err != nil {
+ return err
+ }
+ defer tt.Close()
+
+ p := bufPool.Get().(*[]byte)
+ defer bufPool.Put(p)
+ _, err = io.CopyBuffer(tt, ff, *p)
+ return err
+}
+
+func hasNoIO(r *CreateConfig) bool {
+ return r.Stdin == "" && r.Stdout == "" && r.Stderr == ""
+}