cri-o/server/container_attach.go
Mrunal Patel 8f5f7aa5e2 Add code to handle CRI attach
A goroutine is started to forward terminal resize requests
from the resize channel. Also, data is copied back/forth
between stdin, stdout, stderr streams and the attach socket
for the container.

Signed-off-by: Mrunal Patel <mpatel@redhat.com>
2017-06-06 07:36:52 -07:00

111 lines
2.8 KiB
Go

package server
import (
"fmt"
"io"
"io/ioutil"
"net"
"os"
"path/filepath"
"syscall"
"github.com/Sirupsen/logrus"
"github.com/kubernetes-incubator/cri-o/oci"
"golang.org/x/net/context"
pb "k8s.io/kubernetes/pkg/kubelet/api/v1alpha1/runtime"
kubecontainer "k8s.io/kubernetes/pkg/kubelet/container"
"k8s.io/kubernetes/pkg/util/term"
)
// Attach prepares a streaming endpoint to attach to a running container.
func (s *Server) Attach(ctx context.Context, req *pb.AttachRequest) (*pb.AttachResponse, error) {
logrus.Debugf("AttachRequest %+v", req)
resp, err := s.GetAttach(req)
if err != nil {
return nil, fmt.Errorf("unable to prepare attach endpoint")
}
return resp, nil
}
// Attach endpoint for streaming.Runtime
func (ss streamService) Attach(containerID string, inputStream io.Reader, outputStream, errorStream io.WriteCloser, tty bool, resize <-chan term.Size) error {
c := ss.runtimeServer.GetContainer(containerID)
if c == nil {
return fmt.Errorf("could not find container %q", containerID)
}
if err := ss.runtimeServer.runtime.UpdateStatus(c); err != nil {
return err
}
cState := ss.runtimeServer.runtime.ContainerStatus(c)
if !(cState.Status == oci.ContainerStateRunning || cState.Status == oci.ContainerStateCreated) {
return fmt.Errorf("container is not created or running")
}
controlPath := filepath.Join(c.BundlePath(), "ctl")
controlFile, err := os.OpenFile(controlPath, syscall.O_WRONLY, 0)
if err != nil {
return fmt.Errorf("failed to open container ctl file: %v", err)
}
kubecontainer.HandleResizing(resize, func(size term.Size) {
logrus.Infof("Got a resize event: %+v", size)
_, err := fmt.Fprintf(controlFile, "%d %d %d\n", 1, size.Height, size.Width)
if err != nil {
logrus.Infof("Failed to write to control file to resize terminal: %v", err)
}
})
attachSocketPath := filepath.Join("/var/run/crio", c.ID(), "attach")
conn, err := net.Dial("unix", attachSocketPath)
if err != nil {
return fmt.Errorf("failed to connect to container %s attach socket: %v", c.ID(), err)
}
defer conn.Close()
receiveStdout := make(chan error)
if outputStream != nil || errorStream != nil {
go func() {
receiveStdout <- redirectResponseToOutputStream(tty, outputStream, errorStream, conn)
}()
}
stdinDone := make(chan struct{})
go func() {
if inputStream != nil {
io.Copy(conn, inputStream)
}
close(stdinDone)
}()
select {
case err := <-receiveStdout:
return err
case <-stdinDone:
if outputStream != nil || errorStream != nil {
return <-receiveStdout
}
}
return nil
}
func redirectResponseToOutputStream(tty bool, outputStream, errorStream io.Writer, conn io.Reader) error {
if outputStream == nil {
outputStream = ioutil.Discard
}
if errorStream == nil {
// errorStream = ioutil.Discard
}
var err error
if tty {
_, err = io.Copy(outputStream, conn)
} else {
// TODO
}
return err
}