Merge pull request #4 from technosophos/fix/3-blank-my-ip

fix(aboutme): prevent IP from being blank

Author: technosophos

aboutme/aboutme.go

@@ -12,6 +12,7 @@ package aboutme
 
 import (
 	"errors"
+	"fmt"
 	"net"
 	"os"
 	"strings"
@@ -120,6 +121,16 @@ func (me *Me) init() error {
 	me.Labels = p.Labels
 	me.Annotations = me.Annotations
 
+	// FIXME: It appears that sometimes the k8s API server does not set the
+	// PodIP, even though the pod is issued an IP. We need to figure out why,
+	// and if this is an expected case. In the meantime, we get the IP by
+	// scanning interfaces.
+	if me.IP == "" {
+		// We swallow the error, letting me.IP set the interface address to
+		// 0.0.0.0.
+		me.IP, _ = MyIP()
+	}
+
 	return nil
 }
 
@@ -164,7 +175,21 @@ func (me *Me) findPodInNamespaces() (*api.Pod, string, error) {
 // Because this queries the interfaces, not the Kube API server, this could,
 // in theory, return an IP address different from Me.IP.
 func MyIP() (string, error) {
-	iface, err := net.InterfaceByName("eth0")
+
+	maxIface := 5
+	var err error
+	for i := 0; i < maxIface; i++ {
+		var ip string
+		ip, err = IPByInterface(fmt.Sprintf("eth%d", i))
+		if err == nil {
+			return ip, nil
+		}
+	}
+
+	return "0.0.0.0", err
+}
+func IPByInterface(name string) (string, error) {
+	iface, err := net.InterfaceByName(name)
 	if err != nil {
 		return "", err
 	}

aboutme/aboutme_test.go

@@ -3,6 +3,7 @@ package aboutme
 import (
 	"net"
 	"os"
+	"strings"
 	"testing"
 
 	"k8s.io/kubernetes/pkg/client/unversioned"
@@ -43,6 +44,57 @@ func TestShuntEnv(t *testing.T) {
 	}
 }
 
+func TestMyIPLocal(t *testing.T) {
+	// This version does not require running inside of k8s.
+	ip, _ := MyIP()
+	if len(ip) == 0 {
+		t.Error("Expected a string, got empty")
+	}
+	octets := strings.Split(ip, ".")
+	if len(octets) != 4 {
+		t.Errorf("Expected 4 octets, got %d", len(octets))
+	}
+}
+
+func TestByInterfaceEth0(t *testing.T) {
+	if _, err := net.InterfaceByName("eth0"); err != nil {
+		t.Skip("Host operating system does not have an eth0 device to test.")
+	}
+
+	ip, err := IPByInterface("eth0")
+	if err != nil {
+		t.Errorf("Failed to get eth0: %s", err)
+	}
+	if len(ip) == 0 {
+		t.Error("IP address is empty.")
+	}
+
+	if ip == "0.0.0.0" {
+		t.Error("Got generic IP instead of real one.")
+	}
+
+}
+
+func TestByInterfaceEn0(t *testing.T) {
+	// This works on most Macs.
+	if _, err := net.InterfaceByName("en0"); err != nil {
+		t.Skip("Host operating system does not have an en0 device to test.")
+	}
+
+	ip, err := IPByInterface("en0")
+	if err != nil {
+		t.Errorf("Failed to get en0: %s", err)
+	}
+	if len(ip) == 0 {
+		t.Error("IP address is empty.")
+	}
+
+	if ip == "0.0.0.0" {
+		t.Error("Got generic IP instead of real one.")
+	}
+
+}
+
 func TestMyIP(t *testing.T) {
 	if _, err := net.InterfaceByName("eth0"); err != nil {
 		t.Skip("Host operating system does not have an eth0 device to test.")