Use ip from env

bridge/bridge.go

@@ -317,6 +317,7 @@ func (b *Bridge) newService(port ServicePort, isgroup bool) *Service {
 	}
 
 	// NetworkMode can point to another container (kuberenetes pods)
+	var ipFromNetworkContainer string
 	networkMode := container.HostConfig.NetworkMode
 	if networkMode != "" {
 		if strings.HasPrefix(networkMode, "container:") {
@@ -326,12 +327,37 @@ func (b *Bridge) newService(port ServicePort, isgroup bool) *Service {
 			if err != nil {
 				log.Println("unable to inspect network container:", networkContainerId[:12], err)
 			} else {
-				service.IP = networkContainer.NetworkSettings.IPAddress
-				log.Println(service.Name + ": using network container IP " + service.IP)
+				ipFromNetworkContainer = networkContainer.NetworkSettings.IPAddress
+
+				if ipFromNetworkContainer != "" {
+					service.IP = networkContainer.NetworkSettings.IPAddress
+					log.Println(service.Name + ": using network container IP " + service.IP)
+				} else {
+					log.Println(service.Name + ": network container IP address is empty")
+				}
 			}
 		}
 	}
 
+	// Grab the container IP address from docker or kubernetes env
+	log.Println("Fetch ip using "+ b.config.UseIpFromEnv  + " :" + ipFromNetworkContainer+ "'")
+	if b.config.UseIpFromEnv != "" && ipFromNetworkContainer == "" {
+		log.Println("Going to reset the ip using "+b.config.UseIpFromEnv  + "'")
+		var isIpFound bool = false
+		for _, requiredEnv := range container.Config.Env {
+			if strings.Contains(requiredEnv, b.config.UseIpFromEnv) {
+				service.IP = requiredEnv[len(b.config.UseIpFromEnv)+1:]
+				log.Println(service.Name + ": using container IP '" + service.IP + "' from env '" + b.config.UseIpFromEnv  + "'")
+				isIpFound = true
+				break
+			}
+		}
+		if isIpFound == false {
+			log.Println(service.Name + ": could not found env '" + b.config.UseIpFromEnv  +
+				"' from docker env")
+		}
+	}
+
 	if port.PortType == "udp" {
 		service.Tags = combineTags(
 			mapDefault(metadata, "tags", ""), b.config.ForceTags, "udp")

bridge/types.go

@@ -24,6 +24,7 @@ type Config struct {
 	Internal        bool
 	Explicit        bool
 	UseIpFromLabel  string
+	UseIpFromEnv    string
 	ForceTags       string
 	RefreshTtl      int
 	RefreshInterval int

docs/user/run.md

@@ -44,6 +44,7 @@ Option                           | Since | Description
 `-ttl <seconds>`                 |       | TTL for services. Default: 0, no expiry (supported backends only)
 `-ttl-refresh <seconds>`         |       | Frequency service TTLs are refreshed (supported backends only)
 `-useIpFromLabel <label>`        |       | Uses the IP address stored in the given label, which is assigned to a container, for registration with Consul
+`-useIpFromEnv <env>`        	 |       | Uses the IP address from the given environment variable, which is assigned to a container, for registration with Consul
 
 If the `-internal` option is used, Registrator will register the docker0
 internal IP and port instead of the host mapped ones.

registrator.go

@@ -23,6 +23,7 @@ var hostIp = flag.String("ip", "", "IP for ports mapped to the host")
 var internal = flag.Bool("internal", false, "Use internal ports instead of published ones")
 var explicit = flag.Bool("explicit", false, "Only register containers which have SERVICE_NAME label set")
 var useIpFromLabel = flag.String("useIpFromLabel", "", "Use IP which is stored in a label assigned to the container")
+var useIpFromEnv = flag.String("useIpFromEnv", "", "Use IP from the container environment variable")
 var refreshInterval = flag.Int("ttl-refresh", 0, "Frequency with which service TTLs are refreshed")
 var refreshTtl = flag.Int("ttl", 0, "TTL for services (default is no expiry)")
 var forceTags = flag.String("tags", "", "Append tags for all registered services")
@@ -107,6 +108,7 @@ func main() {
 		Internal:        *internal,
 		Explicit:        *explicit,
 		UseIpFromLabel:  *useIpFromLabel,
+		UseIpFromEnv:    *useIpFromEnv,
 		ForceTags:       *forceTags,
 		RefreshTtl:      *refreshTtl,
 		RefreshInterval: *refreshInterval,

registrator.iml

@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<module type="WEB_MODULE" version="4">
+  <component name="NewModuleRootManager" inherit-compiler-output="true">
+    <exclude-output />
+    <content url="file://$MODULE_DIR$" />
+    <orderEntry type="inheritedJdk" />
+    <orderEntry type="sourceFolder" forTests="false" />
+  </component>
+</module>