kubectl: kubecfg rewrite for better modularity and improved UX

pkg/kubectl/describe.go

@@ -0,0 +1,186 @@
+/*
+Copyright 2014 Google Inc. All rights reserved.
+
+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
+
+    http://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.
+*/
+
+package kubectl
+
+import (
+	"fmt"
+	"io"
+	"strings"
+	"text/tabwriter"
+
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/api"
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/client"
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/labels"
+	"github.com/golang/glog"
+)
+
+func Describe(w io.Writer, c client.Interface, resource, id string) error {
+	var str string
+	var err error
+	path, err := resolveResource(resolveToPath, resource)
+	if err != nil {
+		return err
+	}
+	switch path {
+	case "pods":
+		str, err = describePod(w, c, id)
+	case "replicationControllers":
+		str, err = describeReplicationController(w, c, id)
+	case "services":
+		str, err = describeService(w, c, id)
+	case "minions":
+		str, err = describeMinion(w, c, id)
+	}
+
+	if err != nil {
+		return err
+	}
+
+	_, err = fmt.Fprintf(w, str)
+	return err
+}
+
+func describePod(w io.Writer, c client.Interface, id string) (string, error) {
+	pod, err := c.GetPod(api.NewDefaultContext(), id)
+	if err != nil {
+		return "", err
+	}
+
+	return tabbedString(func(out *tabwriter.Writer) error {
+		fmt.Fprintf(out, "ID:\t%s\n", pod.ID)
+		fmt.Fprintf(out, "Image(s):\t%s\n", makeImageList(pod.DesiredState.Manifest))
+		fmt.Fprintf(out, "Host:\t%s\n", pod.CurrentState.Host+"/"+pod.CurrentState.HostIP)
+		fmt.Fprintf(out, "Labels:\t%s\n", formatLabels(pod.Labels))
+		fmt.Fprintf(out, "Status:\t%s\n", string(pod.CurrentState.Status))
+		fmt.Fprintf(out, "Replication Controllers:\t%s\n", getReplicationControllersForLabels(c, labels.Set(pod.Labels)))
+		return nil
+	})
+}
+
+func describeReplicationController(w io.Writer, c client.Interface, id string) (string, error) {
+	rc, err := c.GetReplicationController(api.NewDefaultContext(), id)
+	if err != nil {
+		return "", err
+	}
+
+	running, waiting, terminated, err := getPodStatusForReplicationController(c, rc)
+	if err != nil {
+		return "", err
+	}
+
+	return tabbedString(func(out *tabwriter.Writer) error {
+		fmt.Fprintf(out, "ID:\t%s\n", rc.ID)
+		fmt.Fprintf(out, "Image(s):\t%s\n", makeImageList(rc.DesiredState.PodTemplate.DesiredState.Manifest))
+		fmt.Fprintf(out, "Selector:\t%s\n", formatLabels(rc.DesiredState.ReplicaSelector))
+		fmt.Fprintf(out, "Labels:\t%s\n", formatLabels(rc.Labels))
+		fmt.Fprintf(out, "Replicas:\t%d current / %d desired\n", rc.CurrentState.Replicas, rc.DesiredState.Replicas)
+		fmt.Fprintf(out, "Pods Status:\t%d Running / %d Waiting / %d Terminated\n", running, waiting, terminated)
+		return nil
+	})
+}
+
+func describeService(w io.Writer, c client.Interface, id string) (string, error) {
+	s, err := c.GetService(api.NewDefaultContext(), id)
+	if err != nil {
+		return "", err
+	}
+
+	return tabbedString(func(out *tabwriter.Writer) error {
+		fmt.Fprintf(out, "ID:\t%s\n", s.ID)
+		fmt.Fprintf(out, "Labels:\t%s\n", formatLabels(s.Labels))
+		fmt.Fprintf(out, "Selector:\t%s\n", formatLabels(s.Selector))
+		fmt.Fprintf(out, "Port:\t%d\n", s.Port)
+		return nil
+	})
+}
+
+func describeMinion(w io.Writer, c client.Interface, id string) (string, error) {
+	m, err := getMinion(c, id)
+	if err != nil {
+		return "", err
+	}
+
+	return tabbedString(func(out *tabwriter.Writer) error {
+		fmt.Fprintf(out, "ID:\t%s\n", m.ID)
+		return nil
+	})
+}
+
+// client.Interface doesn't have GetMinion(id) yet so we hack it up.
+func getMinion(c client.Interface, id string) (*api.Minion, error) {
+	minionList, err := c.ListMinions()
+	if err != nil {
+		glog.Fatalf("Error getting minion info: %v\n", err)
+	}
+
+	for _, m := range minionList.Items {
+		if id == m.TypeMeta.ID {
+			return &m, nil
+		}
+	}
+	return nil, fmt.Errorf("Minion %s not found", id)
+}
+
+// Get all replication controllers whose selectors would match a given set of
+// labels.
+// TODO Move this to pkg/client and ideally implement it server-side (instead
+// of getting all RC's and searching through them manually).
+func getReplicationControllersForLabels(c client.Interface, labelsToMatch labels.Labels) string {
+	// Get all replication controllers.
+	rcs, err := c.ListReplicationControllers(api.NewDefaultContext(), labels.Everything())
+	if err != nil {
+		glog.Fatalf("Error getting replication controllers: %v\n", err)
+	}
+
+	// Find the ones that match labelsToMatch.
+	var matchingRCs []api.ReplicationController
+	for _, rc := range rcs.Items {
+		selector := labels.SelectorFromSet(rc.DesiredState.ReplicaSelector)
+		if selector.Matches(labelsToMatch) {
+			matchingRCs = append(matchingRCs, rc)
+		}
+	}
+
+	// Format the matching RC's into strings.
+	var rcStrings []string
+	for _, rc := range matchingRCs {
+		rcStrings = append(rcStrings, fmt.Sprintf("%s (%d/%d replicas created)", rc.ID, rc.CurrentState.Replicas, rc.DesiredState.Replicas))
+	}
+
+	list := strings.Join(rcStrings, ", ")
+	if list == "" {
+		return "<none>"
+	}
+	return list
+}
+
+func getPodStatusForReplicationController(kubeClient client.Interface, rc *api.ReplicationController) (running, waiting, terminated int, err error) {
+	rcPods, err := kubeClient.ListPods(api.NewDefaultContext(), labels.SelectorFromSet(rc.DesiredState.ReplicaSelector))
+	if err != nil {
+		return
+	}
+	for _, pod := range rcPods.Items {
+		if pod.CurrentState.Status == api.PodRunning {
+			running++
+		} else if pod.CurrentState.Status == api.PodWaiting {
+			waiting++
+		} else if pod.CurrentState.Status == api.PodTerminated {
+			terminated++
+		}
+	}
+	return
+}