diff options
author | Fabricio Voznika <fvoznika@google.com> | 2021-01-12 17:50:33 -0800 |
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committer | gVisor bot <gvisor-bot@google.com> | 2021-01-12 17:54:10 -0800 |
commit | 8b0f0b4d11e0938eec8da411323b2ce35976ab56 (patch) | |
tree | aab8e37ca51133da5bfa4a055ea0dfa0bda514cf /pkg/shim/proc/io.go | |
parent | be2b9d75d75e0e7371cd868589d57f4ddee44781 (diff) |
Delete shim v1
gvisor-containerd-shim is not compatible with containerd 1.1 or earlier.
Starting from containerd 1.2, shim v2 is the preferred interface.
PiperOrigin-RevId: 351485556
Diffstat (limited to 'pkg/shim/proc/io.go')
-rw-r--r-- | pkg/shim/proc/io.go | 162 |
1 files changed, 162 insertions, 0 deletions
diff --git a/pkg/shim/proc/io.go b/pkg/shim/proc/io.go new file mode 100644 index 000000000..34d825fb7 --- /dev/null +++ b/pkg/shim/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 +} |