From 8d904c60949e310893a25c8af3636b0151334dd4 Mon Sep 17 00:00:00 2001
From: ChrisMcKenzie <c.mckenzie@datascience.com>
Date: Fri, 6 Oct 2017 15:24:50 -0700
Subject: [PATCH] added support for useIpFromNetwork

---
 bridge/bridge.go | 16 ++++++++++++++--
 bridge/types.go  | 19 ++++++++++---------
 registrator.go   | 20 +++++++++++---------
 3 files changed, 35 insertions(+), 20 deletions(-)

diff --git a/bridge/bridge.go b/bridge/bridge.go
index f02ca99c9..42ca030a8 100644
--- a/bridge/bridge.go
+++ b/bridge/bridge.go
@@ -202,7 +202,7 @@ func (b *Bridge) add(containerId string, quiet bool) {
 
 	// Extract configured host port mappings, relevant when using --net=host
 	for port, _ := range container.Config.ExposedPorts {
-		published := []dockerapi.PortBinding{ {"0.0.0.0", port.Port()}, }
+		published := []dockerapi.PortBinding{{"0.0.0.0", port.Port()}}
 		ports[string(port)] = servicePort(container, port, published)
 	}
 
@@ -309,13 +309,25 @@ func (b *Bridge) newService(port ServicePort, isgroup bool) *Service {
 				service.IP = containerIp
 			}
 			log.Println("using container IP " + service.IP + " from label '" +
-				b.config.UseIpFromLabel  + "'")
+				b.config.UseIpFromLabel + "'")
 		} else {
 			log.Println("Label '" + b.config.UseIpFromLabel +
 				"' not found in container configuration")
 		}
 	}
 
+	if b.config.UseIpFromNetwork != "" {
+		containerNetwork, ok := container.NetworkSettings.Networks[b.config.UseIpFromNetwork]
+		if ok {
+			service.IP = containerNetwork.IPAddress
+			log.Printf("using container IP %s from network '%s'",
+				service.IP, b.config.UseIpFromLabel)
+		} else {
+			log.Printf("Network '%s' not found in container configuration.",
+				b.config.UseIpFromNetwork)
+		}
+	}
+
 	// NetworkMode can point to another container (kuberenetes pods)
 	networkMode := container.HostConfig.NetworkMode
 	if networkMode != "" {
diff --git a/bridge/types.go b/bridge/types.go
index e643ed3f5..e87ca391a 100644
--- a/bridge/types.go
+++ b/bridge/types.go
@@ -20,15 +20,16 @@ type RegistryAdapter interface {
 }
 
 type Config struct {
-	HostIp          string
-	Internal        bool
-	Explicit        bool
-	UseIpFromLabel  string
-	ForceTags       string
-	RefreshTtl      int
-	RefreshInterval int
-	DeregisterCheck string
-	Cleanup         bool
+	HostIp           string
+	Internal         bool
+	Explicit         bool
+	UseIpFromNetwork string
+	UseIpFromLabel   string
+	ForceTags        string
+	RefreshTtl       int
+	RefreshInterval  int
+	DeregisterCheck  string
+	Cleanup          bool
 }
 
 type Service struct {
diff --git a/registrator.go b/registrator.go
index 0b449b41b..686a6b663 100644
--- a/registrator.go
+++ b/registrator.go
@@ -22,6 +22,7 @@ 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 useIpFromNetwork = flag.String("useIpFromNetwork", "", "Use IP that is assigned on to a containers network")
 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")
@@ -98,15 +99,16 @@ func main() {
 	}
 
 	b, err := bridge.New(docker, flag.Arg(0), bridge.Config{
-		HostIp:          *hostIp,
-		Internal:        *internal,
-		Explicit:        *explicit,
-		UseIpFromLabel:  *useIpFromLabel,
-		ForceTags:       *forceTags,
-		RefreshTtl:      *refreshTtl,
-		RefreshInterval: *refreshInterval,
-		DeregisterCheck: *deregister,
-		Cleanup:         *cleanup,
+		HostIp:           *hostIp,
+		Internal:         *internal,
+		Explicit:         *explicit,
+		UseIpFromNetwork: *useIpFromNetwork,
+		UseIpFromLabel:   *useIpFromLabel,
+		ForceTags:        *forceTags,
+		RefreshTtl:       *refreshTtl,
+		RefreshInterval:  *refreshInterval,
+		DeregisterCheck:  *deregister,
+		Cleanup:          *cleanup,
 	})
 
 	assert(err)