Merge pull request #10277 from brendandburns/health

Switch to using the official etcd health check.

pkg/tools/etcd_helper.go

@@ -17,6 +17,7 @@ limitations under the License.
 package tools
 
 import (
+	"encoding/json"
 	"errors"
 	"fmt"
 	"io/ioutil"
@@ -723,3 +724,19 @@ func NewEtcdClientStartServerIfNecessary(server string) (EtcdClient, error) {
 	servers := []string{server}
 	return etcd.NewClient(servers), nil
 }
+
+type etcdHealth struct {
+	// Note this has to be public so the json library can modify it.
+	Health string `json:health`
+}
+
+func EtcdHealthCheck(data []byte) error {
+	obj := etcdHealth{}
+	if err := json.Unmarshal(data, &obj); err != nil {
+		return err
+	}
+	if obj.Health != "true" {
+		return fmt.Errorf("Unhealthy status: %s", obj.Health)
+	}
+	return nil
+}

pkg/tools/etcd_helper_test.go

@@ -856,3 +856,32 @@ func TestPrefixEtcdKey(t *testing.T) {
 
 	assert.Equal(t, keyBefore, keyAfter, "Prefix incorrectly added by EtcdHelper")
 }
+
+func TestEtcdHealthCheck(t *testing.T) {
+	tests := []struct {
+		data      string
+		expectErr bool
+	}{
+		{
+			data:      "{\"health\": \"true\"}",
+			expectErr: false,
+		},
+		{
+			data:      "{\"health\": \"false\"}",
+			expectErr: true,
+		},
+		{
+			data:      "invalid json",
+			expectErr: true,
+		},
+	}
+	for _, test := range tests {
+		err := EtcdHealthCheck([]byte(test.data))
+		if err != nil && !test.expectErr {
+			t.Errorf("unexpected error: %v", err)
+		}
+		if err == nil && test.expectErr {
+			t.Error("unexpected non-error")
+		}
+	}
+}