Fix for http client call to wireserver (#431)

* modified wireserver call to non-blocking. Fixed logging issue in ipam

* fixed ut

* addressing review comments

* used inithttpclient function

cni/ipam/ipam.go

@@ -19,11 +19,6 @@ import (
 	cniTypesCurr "github.com/containernetworking/cni/pkg/types/current"
 )
 
-const (
-	// Plugin name.
-	name = "azure-vnet-ipam"
-)
-
 var (
 	ipv4DefaultRouteDstPrefix = net.IPNet{net.IPv4zero, net.IPv4Mask(0, 0, 0, 0)}
 )
@@ -35,7 +30,7 @@ type ipamPlugin struct {
 }
 
 // NewPlugin creates a new ipamPlugin object.
-func NewPlugin(config *common.PluginConfig) (*ipamPlugin, error) {
+func NewPlugin(name string, config *common.PluginConfig) (*ipamPlugin, error) {
 	// Setup base plugin.
 	plugin, err := cni.NewPlugin(name, config.Version)
 	if err != nil {

cni/ipam/ipam_test.go

@@ -51,7 +51,7 @@ func TestMain(m *testing.M) {
 	}
 
 	// Create the plugin.
-	plugin, err = NewPlugin(&config)
+	plugin, err = NewPlugin("ipamtest", &config)
 	if err != nil {
 		fmt.Printf("Failed to create IPAM plugin, err:%v.\n", err)
 		return

cni/ipam/plugin/main.go

@@ -10,6 +10,11 @@ import (
 	"github.com/Azure/azure-container-networking/cni"
 	"github.com/Azure/azure-container-networking/cni/ipam"
 	"github.com/Azure/azure-container-networking/common"
+	"github.com/Azure/azure-container-networking/log"
+)
+
+const (
+	name = "azure-vnet-ipam"
 )
 
 // Version is populated by make during build.
@@ -20,7 +25,16 @@ func main() {
 	var config common.PluginConfig
 	config.Version = version
 
-	ipamPlugin, err := ipam.NewPlugin(&config)
+	log.SetName(name)
+	log.SetLevel(log.LevelInfo)
+	if err := log.SetTarget(log.TargetLogfile); err != nil {
+		fmt.Printf("Failed to setup cni logging: %v\n", err)
+		return
+	}
+
+	defer log.Close()
+
+	ipamPlugin, err := ipam.NewPlugin(name, &config)
 	if err != nil {
 		fmt.Printf("Failed to create IPAM plugin, err:%v.\n", err)
 		os.Exit(1)

ipam/azure.go

@@ -5,6 +5,7 @@ package ipam
 
 import (
 	"encoding/xml"
+	"fmt"
 	"net"
 	"net/http"
 	"strings"
@@ -17,9 +18,12 @@ import (
 const (
 	// Host URL to query.
 	azureQueryUrl = "http://168.63.129.16/machine/plugins?comp=nmagent&type=getinterfaceinfov1"
-
 	// Minimum time interval between consecutive queries.
 	azureQueryInterval = 10 * time.Second
+	// http connection timeout
+	httpConnectionTimeout = 10
+	// http response header timeout
+	responseHeaderTimeout = 10
 )
 
 // Microsoft Azure IPAM configuration source.
@@ -84,14 +88,27 @@ func (s *azureSource) refresh() error {
 		return err
 	}
 
+	httpClient := common.InitHttpClient(httpConnectionTimeout, responseHeaderTimeout)
+	if httpClient == nil {
+		log.Errorf("[ipam] Failed intializing http client")
+		return fmt.Errorf("Error intializing http client")
+	}
+
+	log.Printf("[ipam] Wireserver call %v to retrieve IP List", s.queryUrl)
 	// Fetch configuration.
-	resp, err := http.Get(s.queryUrl)
+	resp, err := httpClient.Get(s.queryUrl)
 	if err != nil {
+		log.Printf("[ipam] wireserver call failed with: %v", err)
 		return err
 	}
 
 	defer resp.Body.Close()
 
+	if resp.StatusCode != http.StatusOK {
+		log.Errorf("[ipam] http return error code for wireserver call %+v", resp)
+		return fmt.Errorf("wireserver http error %+v", resp)
+	}
+
 	// Decode XML document.
 	var doc common.XmlDocument
 	decoder := xml.NewDecoder(resp.Body)