cri-o/server/container_exec.go
Antonio Murdaca b211061016
copy using bytes pools
Vendor and use docker/pkg/pools.
pools are used to lower the number of memory allocations and reuse buffers when
processing large streams operations..

The use of pools.Copy avoids io.Copy's internal buffer allocation.
This commit replaces io.Copy with pools.Copy to avoid the allocation of
buffers in io.Copy.

Signed-off-by: Antonio Murdaca <runcom@redhat.com>
2017-06-12 12:53:23 +02:00

107 lines
2.6 KiB
Go

package server
import (
"fmt"
"io"
"os"
"os/exec"
"github.com/Sirupsen/logrus"
"github.com/docker/docker/pkg/pools"
"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"
utilexec "k8s.io/kubernetes/pkg/util/exec"
"k8s.io/kubernetes/pkg/util/term"
)
// Exec prepares a streaming endpoint to execute a command in the container.
func (s *Server) Exec(ctx context.Context, req *pb.ExecRequest) (*pb.ExecResponse, error) {
logrus.Debugf("ExecRequest %+v", req)
resp, err := s.GetExec(req)
if err != nil {
return nil, fmt.Errorf("unable to prepare exec endpoint")
}
return resp, nil
}
// Exec endpoint for streaming.Runtime
func (ss streamService) Exec(containerID string, cmd []string, stdin io.Reader, stdout, stderr 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")
}
args := []string{"exec"}
if tty {
args = append(args, "-t")
}
args = append(args, c.Name())
args = append(args, cmd...)
execCmd := exec.Command(ss.runtimeServer.runtime.Path(c), args...)
var cmdErr error
if tty {
p, err := kubecontainer.StartPty(execCmd)
if err != nil {
return err
}
defer p.Close()
// make sure to close the stdout stream
defer stdout.Close()
kubecontainer.HandleResizing(resize, func(size term.Size) {
term.SetSize(p.Fd(), size)
})
if stdin != nil {
go pools.Copy(p, stdin)
}
if stdout != nil {
go pools.Copy(stdout, p)
}
cmdErr = execCmd.Wait()
} else {
if stdin != nil {
// Use an os.Pipe here as it returns true *os.File objects.
// This way, if you run 'kubectl exec <pod> -i bash' (no tty) and type 'exit',
// the call below to execCmd.Run() can unblock because its Stdin is the read half
// of the pipe.
r, w, err := os.Pipe()
if err != nil {
return err
}
go pools.Copy(w, stdin)
execCmd.Stdin = r
}
if stdout != nil {
execCmd.Stdout = stdout
}
if stderr != nil {
execCmd.Stderr = stderr
}
cmdErr = execCmd.Run()
}
if exitErr, ok := cmdErr.(*exec.ExitError); ok {
return &utilexec.ExitErrorWrapper{ExitError: exitErr}
}
return cmdErr
}