Command exec inside the Pod method

pkg/controller/controller.go

@@ -18,6 +18,7 @@ import (
 )
 
 type Config struct {
+	RestConfig          *rest.Config
 	KubeClient          *kubernetes.Clientset
 	RestClient          *rest.RESTClient
 	EtcdClient          etcdclient.KeysAPI

pkg/controller/exec.go

@@ -0,0 +1,61 @@
+package controller
+
+import (
+	"bytes"
+	"fmt"
+
+	"k8s.io/client-go/pkg/api"
+	"k8s.io/kubernetes/pkg/client/unversioned/remotecommand"
+	remotecommandconsts "k8s.io/apimachinery/pkg/util/remotecommand"
+
+	"github.bus.zalan.do/acid/postgres-operator/pkg/spec"
+)
+
+func (c *Controller) ExecCommand(podName spec.NamespacedName, command []string) (string, error) {
+	var (
+		execOut bytes.Buffer
+		execErr bytes.Buffer
+	)
+
+	pod, err := c.KubeClient.Pods(podName.Namespace).Get(podName.Name)
+	if err != nil {
+		return "", fmt.Errorf("Can't get Pod info: %s", err)
+	}
+
+	if len(pod.Spec.Containers) != 1 {
+		return "", fmt.Errorf("Can't determine which container to use")
+	}
+
+	req := c.RestClient.Post().
+		Resource("pods").
+		Name(podName.Name).
+		Namespace(podName.Namespace).
+		SubResource("exec")
+	req.VersionedParams(&api.PodExecOptions{
+		Container: pod.Spec.Containers[0].Name,
+		Command:   command,
+		Stdout:    true,
+		Stderr:    true,
+	}, api.ParameterCodec)
+
+	exec, err := remotecommand.NewExecutor(c.RestConfig, "POST", req.URL())
+	if err != nil {
+		return "", fmt.Errorf("Failed to init executor: %s", err)
+	}
+
+	err = exec.Stream(remotecommand.StreamOptions{
+		SupportedProtocols: remotecommandconsts.SupportedStreamingProtocols,
+		Stdout:             &execOut,
+		Stderr:             &execErr,
+	})
+
+	if err != nil {
+		return "", fmt.Errorf("Can't execute: %s", err)
+	}
+
+	if execErr.Len() > 0 {
+		return "", fmt.Errorf("Stderr: %s", execErr.String())
+	}
+
+	return execOut.String(), nil
+}