fix(restore): restore REST API pre-check for CVR creation (#38) (#39)

Signed-off-by: mayank <[email protected]>

pkg/cstor/api_service.go

@@ -0,0 +1,118 @@
+/*
+Copyright 2019 The OpenEBS Authors.
+
+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 cstor
+
+import (
+	"bytes"
+	"io/ioutil"
+	"net/http"
+	"strconv"
+	"time"
+
+	"github.com/pkg/errors"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+)
+
+// httpRestCall execute REST API over HTTP
+func (p *Plugin) httpRestCall(url, reqtype string, data []byte) ([]byte, error) {
+	req, err := http.NewRequest(reqtype, url, bytes.NewBuffer(data))
+	if err != nil {
+		return nil, err
+	}
+	req.Header.Add("Content-Type", "application/json")
+
+	c := &http.Client{
+		Timeout: 60 * time.Second,
+	}
+
+	resp, err := c.Do(req)
+	if err != nil {
+		return nil, errors.Errorf("Error when connecting to maya-apiserver : %s", err.Error())
+	}
+
+	defer func() {
+		if err := resp.Body.Close(); err != nil {
+			p.Log.Warnf("Failed to close response : %s", err.Error())
+		}
+	}()
+
+	respdata, err := ioutil.ReadAll(resp.Body)
+	if err != nil {
+		return nil, errors.Errorf("Unable to read response from maya-apiserver : %s", err.Error())
+	}
+
+	code := resp.StatusCode
+	if code != http.StatusOK {
+		return nil, errors.Errorf("Status error{%v}", http.StatusText(code))
+	}
+	return respdata, nil
+}
+
+// getMapiAddr return maya API server's ip address
+func (p *Plugin) getMapiAddr() string {
+	var openebsNs string
+
+	// check if user has provided openebs namespace
+	if p.namespace != "" {
+		openebsNs = p.namespace
+	} else {
+		openebsNs = metav1.NamespaceAll
+	}
+
+	svclist, err := p.K8sClient.
+		CoreV1().
+		Services(openebsNs).
+		List(
+			metav1.ListOptions{
+				LabelSelector: mayaAPIServiceLabel,
+			},
+		)
+
+	if err != nil {
+		p.Log.Errorf("Error getting maya-apiservice : %v", err.Error())
+		return ""
+	}
+
+	if len(svclist.Items) != 0 {
+		goto fetchip
+	}
+
+	// There are no any services having MayaApiService Label
+	// Let's try to find by name only..
+	svclist, err = p.K8sClient.
+		CoreV1().
+		Services(openebsNs).
+		List(
+			metav1.ListOptions{
+				FieldSelector: "metadata.name=" + mayaAPIServiceName,
+			})
+	if err != nil {
+		p.Log.Errorf("Error getting IP Address for service{%s} : %v", mayaAPIServiceName, err.Error())
+		return ""
+	}
+
+fetchip:
+	for _, s := range svclist.Items {
+		if len(s.Spec.ClusterIP) != 0 {
+			// update the namespace
+			p.namespace = s.Namespace
+			return "http://" + s.Spec.ClusterIP + ":" + strconv.FormatInt(int64(s.Spec.Ports[0].Port), 10)
+		}
+	}
+
+	return ""
+}