containerd/cio/io_unix.go
Daniel Nephin 7d4337e738 Reduce the number of IO constructors
Signed-off-by: Daniel Nephin <dnephin@gmail.com>
2017-12-11 15:07:09 -05:00

127 lines
2.8 KiB
Go

// +build !windows
package cio
import (
"context"
"io"
"io/ioutil"
"os"
"path/filepath"
"sync"
"syscall"
"github.com/containerd/fifo"
"github.com/pkg/errors"
)
// NewFIFOSetInDir returns a new FIFOSet with paths in a temporary directory under root
func NewFIFOSetInDir(root, id string, terminal bool) (*FIFOSet, error) {
if root != "" {
if err := os.MkdirAll(root, 0700); err != nil {
return nil, err
}
}
dir, err := ioutil.TempDir(root, "")
if err != nil {
return nil, err
}
closer := func() error {
return os.RemoveAll(dir)
}
return NewFIFOSet(Config{
Stdin: filepath.Join(dir, id+"-stdin"),
Stdout: filepath.Join(dir, id+"-stdout"),
Stderr: filepath.Join(dir, id+"-stderr"),
Terminal: terminal,
}, closer), nil
}
func copyIO(fifos *FIFOSet, ioset *Streams) (*cio, error) {
var ctx, cancel = context.WithCancel(context.Background())
pipes, err := openFifos(ctx, fifos)
if err != nil {
cancel()
return nil, err
}
if fifos.Stdin != "" {
go func() {
io.Copy(pipes.Stdin, ioset.Stdin)
pipes.Stdin.Close()
}()
}
var wg = &sync.WaitGroup{}
wg.Add(1)
go func() {
io.Copy(ioset.Stdout, pipes.Stdout)
pipes.Stdout.Close()
wg.Done()
}()
if !fifos.Terminal {
wg.Add(1)
go func() {
io.Copy(ioset.Stderr, pipes.Stderr)
pipes.Stderr.Close()
wg.Done()
}()
}
return &cio{
config: fifos.Config,
wg: wg,
closers: append(pipes.closers(), fifos),
cancel: cancel,
}, nil
}
func openFifos(ctx context.Context, fifos *FIFOSet) (pipes, error) {
var err error
defer func() {
if err != nil {
fifos.Close()
}
}()
var f pipes
if fifos.Stdin != "" {
if f.Stdin, err = fifo.OpenFifo(ctx, fifos.Stdin, syscall.O_WRONLY|syscall.O_CREAT|syscall.O_NONBLOCK, 0700); err != nil {
return f, errors.Wrapf(err, "failed to open stdin fifo")
}
}
if fifos.Stdout != "" {
if f.Stdout, err = fifo.OpenFifo(ctx, fifos.Stdout, syscall.O_RDONLY|syscall.O_CREAT|syscall.O_NONBLOCK, 0700); err != nil {
f.Stdin.Close()
return f, errors.Wrapf(err, "failed to open stdout fifo")
}
}
if fifos.Stderr != "" {
if f.Stderr, err = fifo.OpenFifo(ctx, fifos.Stderr, syscall.O_RDONLY|syscall.O_CREAT|syscall.O_NONBLOCK, 0700); err != nil {
f.Stdin.Close()
f.Stdout.Close()
return f, errors.Wrapf(err, "failed to open stderr fifo")
}
}
return f, nil
}
// NewDirectIO returns an IO implementation that exposes the IO streams as io.ReadCloser
// and io.WriteCloser.
func NewDirectIO(ctx context.Context, fifos *FIFOSet) (*DirectIO, error) {
ctx, cancel := context.WithCancel(ctx)
pipes, err := openFifos(ctx, fifos)
return &DirectIO{
pipes: pipes,
cio: cio{
config: fifos.Config,
closers: append(pipes.closers(), fifos),
cancel: cancel,
},
}, err
}
func (p *pipes) closers() []io.Closer {
return []io.Closer{p.Stdin, p.Stdout, p.Stderr}
}