Refactor container io code

Signed-off-by: Lantao Liu <lantaol@google.com>
2017-11-10 18:34:09 +00:00
parent b6de04772d
commit e41b6d3c24
8 changed files with 400 additions and 402 deletions
--- a/pkg/server/io/helpers.go
+++ b/pkg/server/io/helpers.go
@@ -0,0 +1,148 @@
+/*
+Copyright 2017 The Kubernetes 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
+
+    http://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 io
+
+import (
+	"io"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"sync"
+	"syscall"
+
+	"github.com/containerd/containerd"
+	"github.com/containerd/fifo"
+	"golang.org/x/net/context"
+)
+
+// AttachOptions specifies how to attach to a container.
+type AttachOptions struct {
+	Stdin     io.Reader
+	Stdout    io.WriteCloser
+	Stderr    io.WriteCloser
+	Tty       bool
+	StdinOnce bool
+	// CloseStdin is the function to close container stdin.
+	CloseStdin func() error
+}
+
+// StreamType is the type of the stream, stdout/stderr.
+type StreamType string
+
+const (
+	// Stdin stream type.
+	Stdin StreamType = "stdin"
+	// Stdout stream type.
+	Stdout StreamType = "stdout"
+	// Stderr stream type.
+	Stderr StreamType = "stderr"
+)
+
+type wgCloser struct {
+	ctx    context.Context
+	wg     *sync.WaitGroup
+	set    []io.Closer
+	cancel context.CancelFunc
+}
+
+func (g *wgCloser) Wait() {
+	g.wg.Wait()
+}
+
+func (g *wgCloser) Close() {
+	for _, f := range g.set {
+		f.Close()
+	}
+}
+
+func (g *wgCloser) Cancel() {
+	g.cancel()
+}
+
+// newFifos creates fifos directory for a container.
+func newFifos(root, id string, tty, stdin bool) (*containerd.FIFOSet, error) {
+	root = filepath.Join(root, "io")
+	if err := os.MkdirAll(root, 0700); err != nil {
+		return nil, err
+	}
+	dir, err := ioutil.TempDir(root, "")
+	if err != nil {
+		return nil, err
+	}
+	fifos := &containerd.FIFOSet{
+		Dir:      dir,
+		In:       filepath.Join(dir, id+"-stdin"),
+		Out:      filepath.Join(dir, id+"-stdout"),
+		Err:      filepath.Join(dir, id+"-stderr"),
+		Terminal: tty,
+	}
+	if !stdin {
+		fifos.In = ""
+	}
+	return fifos, nil
+}
+
+type stdioPipes struct {
+	stdin  io.WriteCloser
+	stdout io.ReadCloser
+	stderr io.ReadCloser
+}
+
+// newStdioPipes creates actual fifos for stdio.
+func newStdioPipes(fifos *containerd.FIFOSet) (_ *stdioPipes, _ *wgCloser, err error) {
+	var (
+		f           io.ReadWriteCloser
+		set         []io.Closer
+		ctx, cancel = context.WithCancel(context.Background())
+		p           = &stdioPipes{}
+	)
+	defer func() {
+		if err != nil {
+			for _, f := range set {
+				f.Close()
+			}
+			cancel()
+		}
+	}()
+
+	if fifos.In != "" {
+		if f, err = fifo.OpenFifo(ctx, fifos.In, syscall.O_WRONLY|syscall.O_CREAT|syscall.O_NONBLOCK, 0700); err != nil {
+			return nil, nil, err
+		}
+		p.stdin = f
+		set = append(set, f)
+	}
+
+	if f, err = fifo.OpenFifo(ctx, fifos.Out, syscall.O_RDONLY|syscall.O_CREAT|syscall.O_NONBLOCK, 0700); err != nil {
+		return nil, nil, err
+	}
+	p.stdout = f
+	set = append(set, f)
+
+	if f, err = fifo.OpenFifo(ctx, fifos.Err, syscall.O_RDONLY|syscall.O_CREAT|syscall.O_NONBLOCK, 0700); err != nil {
+		return nil, nil, err
+	}
+	p.stderr = f
+	set = append(set, f)
+
+	return p, &wgCloser{
+		wg:     &sync.WaitGroup{},
+		set:    set,
+		ctx:    ctx,
+		cancel: cancel,
+	}, nil
+}