Add IP look up if the Cloud Provider is not null

Add Instance info to the Cloud Provider interface

pkg/cloudprovider/cloud.go

@@ -16,10 +16,16 @@ limitations under the License.
 
 package cloudprovider
 
+import (
+	"net"
+)
+
 // CloudInterface is an abstract, pluggable interface for cloud providers
 type Interface interface {
 	// TCPLoadBalancer returns a balancer interface, or nil if none is supported.  Returns an error if one occurs.
 	TCPLoadBalancer() (TCPLoadBalancer, error)
+	// Instances returns an instances interface, or nil if none is supported.  Returns an error if one occurs.
+	Instances() (Instances, error)
 }
 
 type TCPLoadBalancer interface {
@@ -29,3 +35,7 @@ type TCPLoadBalancer interface {
 	UpdateTCPLoadBalancer(name, region string, hosts []string) error
 	DeleteTCPLoadBalancer(name, region string) error
 }
+
+type Instances interface {
+	IPAddress(name string) (net.IP, error)
+}

pkg/cloudprovider/gce.go

@@ -19,6 +19,7 @@ package cloudprovider
 import (
 	"fmt"
 	"io/ioutil"
+	"net"
 	"net/http"
 	"strconv"
 	"strings"
@@ -82,6 +83,10 @@ func (gce *GCECloud) TCPLoadBalancer() (TCPLoadBalancer, error) {
 	return gce, nil
 }
 
+func (gce *GCECloud) Instances() (Instances, error) {
+	return gce, nil
+}
+
 func makeHostLink(projectID, zone, host string) string {
 	ix := strings.Index(host, ".")
 	if ix != -1 {
@@ -162,3 +167,15 @@ func (gce *GCECloud) DeleteTCPLoadBalancer(name, region string) error {
 	_, err = gce.service.TargetPools.Delete(gce.projectID, region, name).Do()
 	return err
 }
+
+func (gce *GCECloud) IPAddress(instance string) (net.IP, error) {
+	res, err := gce.service.Instances.Get(gce.projectID, gce.zone, instance).Do()
+	if err != nil {
+		return nil, err
+	}
+	ip := net.ParseIP(res.NetworkInterfaces[0].AccessConfigs[0].NatIP)
+	if ip == nil {
+		return nil, fmt.Errorf("Invalid network IP: %s", res.NetworkInterfaces[0].AccessConfigs[0].NatIP)
+	}
+	return ip, nil
+}