construct master URIs from MasterInfo.Address if present; prefer /state over /state.json

pkg/cloudprovider/providers/mesos/client.go

@@ -19,6 +19,7 @@ package mesos
 import (
 	"encoding/binary"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"io/ioutil"
 	"net"
@@ -37,7 +38,7 @@ import (
 
 const defaultClusterName = "mesos"
 
-var noLeadingMasterError = fmt.Errorf("there is no current leading master available to query")
+var noLeadingMasterError = errors.New("there is no current leading master available to query")
 
 type mesosClient struct {
 	masterLock    sync.RWMutex
@@ -136,17 +137,11 @@ func createMesosClient(
 	client.state.refill = client.pollMasterForState
 	first := true
 	if err := md.Detect(detector.OnMasterChanged(func(info *mesos.MasterInfo) {
-		client.masterLock.Lock()
-		defer client.masterLock.Unlock()
-		if info == nil {
-			client.master = ""
-		} else if host := info.GetHostname(); host != "" {
-			client.master = host
-		} else {
-			client.master = unpackIPv4(info.GetIp())
-		}
-		if len(client.master) > 0 {
-			client.master = fmt.Sprintf("%s:%d", client.master, info.GetPort())
+		host, port := extractMasterAddress(info)
+		if len(host) > 0 {
+			client.masterLock.Lock()
+			defer client.masterLock.Unlock()
+			client.master = fmt.Sprintf("%s:%d", host, port)
 			if first {
 				first = false
 				close(initialMaster)
@@ -160,6 +155,28 @@ func createMesosClient(
 	return client, nil
 }
 
+func extractMasterAddress(info *mesos.MasterInfo) (host string, port int) {
+	if info != nil {
+		host = info.GetAddress().GetHostname()
+		if host == "" {
+			host = info.GetAddress().GetIp()
+		}
+
+		if host != "" {
+			// use port from Address
+			port = int(info.GetAddress().GetPort())
+		} else {
+			// deprecated: get host and port directly from MasterInfo (and not Address)
+			host = info.GetHostname()
+			if host == "" {
+				host = unpackIPv4(info.GetIp())
+			}
+			port = int(info.GetPort())
+		}
+	}
+	return
+}
+
 func unpackIPv4(ip uint32) string {
 	octets := make([]byte, 4, 4)
 	binary.BigEndian.PutUint32(octets, ip)
@@ -198,20 +215,8 @@ func (c *mesosClient) pollMasterForState(ctx context.Context) (*mesosState, erro
 
 	//TODO(jdef) should not assume master uses http (what about https?)
 
-	uri := fmt.Sprintf("http://%s/state.json", master)
-	req, err := http.NewRequest("GET", uri, nil)
-	if err != nil {
-		return nil, err
-	}
 	var state *mesosState
-	err = c.httpDo(ctx, req, func(res *http.Response, err error) error {
-		if err != nil {
-			return err
-		}
-		defer res.Body.Close()
-		if res.StatusCode != 200 {
-			return fmt.Errorf("HTTP request failed with code %d: %v", res.StatusCode, res.Status)
-		}
+	successHandler := func(res *http.Response) error {
 		blob, err1 := ioutil.ReadAll(res.Body)
 		if err1 != nil {
 			return err1
@@ -219,8 +224,51 @@ func (c *mesosClient) pollMasterForState(ctx context.Context) (*mesosState, erro
 		log.V(3).Infof("Got mesos state, content length %v", len(blob))
 		state, err1 = parseMesosState(blob)
 		return err1
-	})
-	return state, err
+	}
+	// thinking here is that we may get some other status codes from mesos at some point:
+	// - authentication
+	// - redirection (possibly from http to https)
+	// ...
+	for _, tt := range []struct {
+		uri      string
+		handlers map[int]func(*http.Response) error
+	}{
+		{
+			uri: fmt.Sprintf("http://%s/state", master),
+			handlers: map[int]func(*http.Response) error{
+				200: successHandler,
+			},
+		},
+		{
+			uri: fmt.Sprintf("http://%s/state.json", master),
+			handlers: map[int]func(*http.Response) error{
+				200: successHandler,
+			},
+		},
+	} {
+		req, err := http.NewRequest("GET", tt.uri, nil)
+		if err != nil {
+			return nil, err
+		}
+		err = c.httpDo(ctx, req, func(res *http.Response, err error) error {
+			if err != nil {
+				return err
+			}
+			defer res.Body.Close()
+			if handler, ok := tt.handlers[res.StatusCode]; ok {
+				err1 := handler(res)
+				if err1 != nil {
+					return err1
+				}
+			}
+			// no handler for this error code, proceed to the next connection type
+			return nil
+		})
+		if state != nil || err != nil {
+			return state, err
+		}
+	}
+	return nil, errors.New("failed to sync with Mesos master")
 }
 
 func parseMesosState(blob []byte) (*mesosState, error) {