gvisor/pkg/shim/service_linux.go

110 lines
2.6 KiB
Go

// 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.
//go:build linux
// +build linux
package shim
import (
"context"
"fmt"
"io"
"sync"
"github.com/containerd/console"
"github.com/containerd/fifo"
"golang.org/x/sys/unix"
)
type linuxPlatform struct {
epoller *console.Epoller
}
func (p *linuxPlatform) CopyConsole(ctx context.Context, console console.Console, stdin, stdout, stderr string, wg *sync.WaitGroup) (console.Console, error) {
if p.epoller == nil {
return nil, fmt.Errorf("uninitialized epoller")
}
epollConsole, err := p.epoller.Add(console)
if err != nil {
return nil, err
}
if stdin != "" {
in, err := fifo.OpenFifo(context.Background(), stdin, unix.O_RDONLY|unix.O_NONBLOCK, 0)
if err != nil {
return nil, err
}
go func() {
p := bufPool.Get().(*[]byte)
defer bufPool.Put(p)
io.CopyBuffer(epollConsole, in, *p)
}()
}
outw, err := fifo.OpenFifo(ctx, stdout, unix.O_WRONLY, 0)
if err != nil {
return nil, err
}
outr, err := fifo.OpenFifo(ctx, stdout, unix.O_RDONLY, 0)
if err != nil {
return nil, err
}
wg.Add(1)
go func() {
p := bufPool.Get().(*[]byte)
defer bufPool.Put(p)
io.CopyBuffer(outw, epollConsole, *p)
epollConsole.Close()
outr.Close()
outw.Close()
wg.Done()
}()
return epollConsole, nil
}
func (p *linuxPlatform) ShutdownConsole(ctx context.Context, cons console.Console) error {
if p.epoller == nil {
return fmt.Errorf("uninitialized epoller")
}
epollConsole, ok := cons.(*console.EpollConsole)
if !ok {
return fmt.Errorf("expected EpollConsole, got %#v", cons)
}
return epollConsole.Shutdown(p.epoller.CloseConsole)
}
func (p *linuxPlatform) Close() error {
return p.epoller.Close()
}
// initialize a single epoll fd to manage our consoles. `initPlatform` should
// only be called once.
func (s *service) initPlatform() error {
if s.platform != nil {
return nil
}
epoller, err := console.NewEpoller()
if err != nil {
return fmt.Errorf("failed to initialize epoller: %w", err)
}
s.platform = &linuxPlatform{
epoller: epoller,
}
go epoller.Wait()
return nil
}