Merge pull request #30 from Nitro/relistan/allow-disabling-ips

Adds a configuration setting to force the old haproxy.cfg behavior

config.go

@@ -20,6 +20,7 @@ type HAproxyConfig struct {
 	Disable      bool   `toml:"disable"`
 	User         string `toml:"user"`
 	Group        string `toml:"group"`
+	UseHostnames bool   `toml:"use_hostnames"`
 }
 
 type ServicesConfig struct {

docker/s6/services/sidecar.svc/run

@@ -22,6 +22,11 @@ if [[ -n "$BIND_IP" ]]; then
 	sed -i.bak 's~^bind_ip *=.*$~bind_ip = "'"$BIND_IP"'"~' sidecar.toml
 fi
 
+# If we're disabling IP addresses in the HAproxy configs
+if [[ -n "$USE_HOSTNAMES" ]]; then
+	sed -i.bak 's~^use_hostnames *=.*$~use_hostnames = "'"$USE_HOSTNAMES"'"~' sidecar.toml
+fi
+
 BIND_IP=`grep bind_ip sidecar.toml | grep -o "[0-9]*\.[0-9]*\.[0-9]*\.[0-9]*"`
 
 # If there's a BIND_IP and we don't already have it, add the

docker/sidecar.docker.toml

@@ -20,6 +20,7 @@ config_file   = "/etc/haproxy.cfg"
 pid_file      = "/var/run/haproxy.pid"
 user          = "haproxy"
 group         = "haproxy"
+use_hostnames = false
 
 [listeners]
 urls = [ "http://192.168.168.168:7778/update" ]

haproxy/haproxy.go

@@ -31,6 +31,7 @@ type HAproxy struct {
 	PidFile      string `toml:"pid_file"`
 	User         string `toml:"user"`
 	Group        string `toml:"group"`
+	UseHostnames bool   `toml:"use_hostnames"`
 	eventChannel chan catalog.ChangeEvent
 }
 
@@ -100,7 +101,13 @@ func findPortForService(svcPort string, svc *service.Service) string {
 }
 
 // Find the matching IP address when given a ServicePort
-func findIpForService(svcPort string, svc *service.Service) string {
+func (h *HAproxy) findIpForService(svcPort string, svc *service.Service) string {
+	// We can turn off using IP addresses in the config, which is sometimes
+	// necessary (e.g. w/Docker for Mac).
+	if h.UseHostnames {
+		return svc.Hostname
+	}
+
 	matchPort, err := strconv.ParseInt(svcPort, 10, 64)
 	if err != nil {
 		log.Errorf("Invalid value from template ('%s') can't parse as int64: %s", svcPort, err.Error())
@@ -151,7 +158,7 @@ func (h *HAproxy) WriteConfig(state *catalog.ServicesState, output io.Writer) er
 			return ports[k]
 		},
 		"portFor":      findPortForService,
-		"ipFor":        findIpForService,
+		"ipFor":        h.findIpForService,
 		"bindIP":       func() string { return h.BindIP },
 		"sanitizeName": sanitizeName,
 	}

haproxy/haproxy_test.go

@@ -105,6 +105,22 @@ func Test_HAproxy(t *testing.T) {
 			So(result["some-svc"], ShouldEqual, "tcp")
 		})
 
+		Convey("findIpForService() returns hostnames when UseHostnames is set", func() {
+			proxy.UseHostnames = true
+			svc := services[0]
+			result := proxy.findIpForService("8080", &svc)
+
+			So(result, ShouldEqual, "indomitable")
+		})
+
+		Convey("findIpForService() returns IP addresses when UseHostnames is false", func() {
+			proxy.UseHostnames = false
+			svc := services[0]
+			result := proxy.findIpForService("8080", &svc)
+
+			So(result, ShouldEqual, "127.0.0.1")
+		})
+
 		Convey("servicesWithPorts() groups services by name and port", func() {
 			badSvc := service.Service{
 				ID:       "0000bad00000",
@@ -192,11 +208,11 @@ func Test_HAproxy(t *testing.T) {
 		Convey("Reload() returns an error when it fails", func() {
 			proxy.ReloadCmd = "sh -c 'exit 1'"
 			err := proxy.Reload()
-			So(err.Error(), ShouldEqual, "exit status 1")
+			So(err.Error(), ShouldContainSubstring, "exit status 1")
 
 			proxy.ReloadCmd = "yomomma"
 			err = proxy.Reload()
-			So(err.Error(), ShouldEqual, "exit status 127")
+			So(err.Error(), ShouldContainSubstring, "exit status 127")
 		})
 
 		Convey("WriteAndReload() bubbles up errors on failure", func() {

main.go

@@ -65,6 +65,8 @@ func configureHAproxy(config Config) *haproxy.HAproxy {
 		proxy.Group = config.HAproxy.Group
 	}
 
+	proxy.UseHostnames = config.HAproxy.UseHostnames
+
 	return proxy
 }
 

sidecar.example.toml

@@ -48,6 +48,12 @@ template_file = "views/haproxy.cfg"
 config_file   = "/etc/haproxy.cfg"
 pid_file      = "/var/run/haproxy.pid"
 
+# This setting will force HAproxy configs to be written
+# using hostnames rather than IP addresses. This can be
+# required when using Docker for Mac, for example, or
+# in a situation where there is some address remapping.
+use_hostnames = false
+
 # URLs can be subscribed to Sidecar state change events.
 # Each URL in the list will be posted to with a copy
 # of the event, which contains the service that changed