From 33381a783a899b24d9c2d7b29808257adc07f1db Mon Sep 17 00:00:00 2001
From: Alex Ellis <alexellis2@gmail.com>
Date: Thu, 27 Jul 2017 12:24:37 +0100
Subject: [PATCH] External alert-handler support.

---
 gateway/plugin/external.go | 31 +++++++++++++++++++++++++++++++
 gateway/server.go          |  5 ++++-
 2 files changed, 35 insertions(+), 1 deletion(-)
 create mode 100644 gateway/plugin/external.go

diff --git a/gateway/plugin/external.go b/gateway/plugin/external.go
new file mode 100644
index 00000000..ded64c81
--- /dev/null
+++ b/gateway/plugin/external.go
@@ -0,0 +1,31 @@
+package plugin
+
+import (
+	"net/url"
+
+	"github.com/alexellis/faas/gateway/handlers"
+)
+
+func NewExternalServiceQuery(externalURL url.URL) handlers.ServiceQuery {
+	return ExternalServiceQuery{
+		URL: externalURL,
+	}
+}
+
+type ExternalServiceQuery struct {
+	URL url.URL
+}
+
+// GetReplicas replica count for function
+func (s ExternalServiceQuery) GetReplicas(serviceName string) (uint64, uint64, error) {
+	var err error
+
+	return 0, 0, err
+}
+
+// SetReplicas update the replica count
+func (s ExternalServiceQuery) SetReplicas(serviceName string, count uint64) error {
+	var err error
+
+	return err
+}
diff --git a/gateway/server.go b/gateway/server.go
index 450ed885..4817cc67 100644
--- a/gateway/server.go
+++ b/gateway/server.go
@@ -14,6 +14,7 @@ import (
 	"github.com/Sirupsen/logrus"
 	internalHandlers "github.com/alexellis/faas/gateway/handlers"
 	"github.com/alexellis/faas/gateway/metrics"
+	"github.com/alexellis/faas/gateway/plugin"
 	"github.com/alexellis/faas/gateway/types"
 	"github.com/docker/docker/client"
 	"github.com/prometheus/client_golang/prometheus"
@@ -69,7 +70,9 @@ func main() {
 
 		faasHandlers.Proxy = makeHandler(reverseProxy, &metricsOptions)
 		faasHandlers.RoutelessProxy = makeHandler(reverseProxy, &metricsOptions)
-		faasHandlers.Alert = makeHandler(reverseProxy, &metricsOptions)
+
+		faasHandlers.Alert = internalHandlers.MakeAlertHandler(plugin.NewExternalServiceQuery(*config.FunctionsProviderURL))
+
 		faasHandlers.ListFunctions = makeHandler(reverseProxy, &metricsOptions)
 		faasHandlers.DeployFunction = makeHandler(reverseProxy, &metricsOptions)
 		faasHandlers.DeleteFunction = makeHandler(reverseProxy, &metricsOptions)