From 478d51c8272c4ff5e07a4daf0821b745e502bea9 Mon Sep 17 00:00:00 2001
From: Manuel de Brito Fontes <aledbf@gmail.com>
Date: Sat, 26 Nov 2016 21:09:59 -0300
Subject: [PATCH] Add healthz checker

---
 controllers/nginx/pkg/cmd/controller/nginx.go | 19 ++++++++++++++++
 core/pkg/ingress/controller/controller.go     | 22 -------------------
 core/pkg/ingress/controller/launch.go         |  6 ++++-
 core/pkg/ingress/doc.go                       |  8 +++++++
 core/pkg/ingress/types.go                     |  5 +++++
 5 files changed, 37 insertions(+), 23 deletions(-)

diff --git a/controllers/nginx/pkg/cmd/controller/nginx.go b/controllers/nginx/pkg/cmd/controller/nginx.go
index 92ff980c9..b2a4cec94 100644
--- a/controllers/nginx/pkg/cmd/controller/nginx.go
+++ b/controllers/nginx/pkg/cmd/controller/nginx.go
@@ -20,6 +20,7 @@ import (
 	"bytes"
 	"fmt"
 	"io/ioutil"
+	"net/http"
 	"os"
 	"os/exec"
 
@@ -252,6 +253,24 @@ func (n NGINXController) OnUpdate(cmap *api.ConfigMap, ingressCfg ingress.Config
 	}, n.testTemplate)
 }
 
+// Name returns the healthcheck name
+func (n NGINXController) Name() string {
+	return "Ingress Controller"
+}
+
+// Check returns if the nginx healthz endpoint is returning ok (status code 200)
+func (n NGINXController) Check(_ *http.Request) error {
+	res, err := http.Get("http://127.0.0.1:18080/healthz")
+	if err != nil {
+		return err
+	}
+	defer res.Body.Close()
+	if res.StatusCode != 200 {
+		return fmt.Errorf("Ingress controller is not healthy")
+	}
+	return nil
+}
+
 // http://graphics.stanford.edu/~seander/bithacks.html#RoundUpPowerOf2
 // https://play.golang.org/p/TVSyCcdxUh
 func nextPowerOf2(v int) int {
diff --git a/core/pkg/ingress/controller/controller.go b/core/pkg/ingress/controller/controller.go
index 1306e4e01..73ed53e18 100644
--- a/core/pkg/ingress/controller/controller.go
+++ b/core/pkg/ingress/controller/controller.go
@@ -18,7 +18,6 @@ package controller
 
 import (
 	"fmt"
-	"net/http"
 	"reflect"
 	"sort"
 	"strconv"
@@ -35,7 +34,6 @@ import (
 	unversionedcore "k8s.io/kubernetes/pkg/client/clientset_generated/internalclientset/typed/core/internalversion"
 	"k8s.io/kubernetes/pkg/client/record"
 	"k8s.io/kubernetes/pkg/fields"
-	"k8s.io/kubernetes/pkg/healthz"
 	"k8s.io/kubernetes/pkg/util/flowcontrol"
 	"k8s.io/kubernetes/pkg/util/intstr"
 
@@ -78,8 +76,6 @@ var (
 
 // GenericController holds the boilerplate code required to build an Ingress controlller.
 type GenericController struct {
-	healthz.HealthzChecker
-
 	cfg *Configuration
 
 	ingController  *cache.Controller
@@ -283,24 +279,6 @@ func (ic *GenericController) controllersInSync() bool {
 		ic.mapController.HasSynced()
 }
 
-// Name returns the healthcheck name
-func (ic GenericController) Name() string {
-	return "Ingress Controller"
-}
-
-// Check returns if the nginx healthz endpoint is returning ok (status code 200)
-func (ic GenericController) Check(_ *http.Request) error {
-	res, err := http.Get("http://127.0.0.1:18080/healthz")
-	if err != nil {
-		return err
-	}
-	defer res.Body.Close()
-	if res.StatusCode != 200 {
-		return fmt.Errorf("Ingress controller is not healthy")
-	}
-	return nil
-}
-
 // Info returns information about the backend
 func (ic GenericController) Info() *ingress.BackendInfo {
 	return ic.cfg.Backend.Info()
diff --git a/core/pkg/ingress/controller/launch.go b/core/pkg/ingress/controller/launch.go
index 41dbaf284..b21c648bf 100644
--- a/core/pkg/ingress/controller/launch.go
+++ b/core/pkg/ingress/controller/launch.go
@@ -155,7 +155,11 @@ func NewIngressController(backend ingress.Controller) *GenericController {
 
 func registerHandlers(enableProfiling bool, port int, ic *GenericController) {
 	mux := http.NewServeMux()
-	healthz.InstallHandler(mux, ic)
+	// expose health check endpoint (/healthz)
+	healthz.InstallHandler(mux,
+		healthz.PingHealthz,
+		ic.cfg.Backend,
+	)
 
 	mux.Handle("/metrics", prometheus.Handler())
 
diff --git a/core/pkg/ingress/doc.go b/core/pkg/ingress/doc.go
index 54ddb718f..068cdaecc 100644
--- a/core/pkg/ingress/doc.go
+++ b/core/pkg/ingress/doc.go
@@ -55,6 +55,14 @@ package ingress
 //     return ingress.NewStandardDefaults()
 // }
 //
+// func (n DummyController) Name() string {
+// 	   return "dummy Controller"
+// }
+//
+// func (n DummyController) Check(_ *http.Request) error {
+//     return nil
+// }
+//
 // func (dc DummyController) Info() *BackendInfo {
 //     Name: "dummy",
 //   Release: "0.0.0",
diff --git a/core/pkg/ingress/types.go b/core/pkg/ingress/types.go
index c1dfc0fa2..7a0f5929a 100644
--- a/core/pkg/ingress/types.go
+++ b/core/pkg/ingress/types.go
@@ -18,6 +18,7 @@ package ingress
 
 import (
 	"k8s.io/kubernetes/pkg/api"
+	"k8s.io/kubernetes/pkg/healthz"
 
 	"k8s.io/ingress/core/pkg/ingress/annotations/auth"
 	"k8s.io/ingress/core/pkg/ingress/annotations/authreq"
@@ -40,6 +41,10 @@ var (
 // Controller holds the methods to handle an Ingress backend
 // TODO (#18): Make sure this is sufficiently supportive of other backends.
 type Controller interface {
+	// HealthzChecker returns is a named healthz check that returns the ingress
+	// controller status
+	healthz.HealthzChecker
+
 	// Reload takes a byte array representing the new loadbalancer configuration,
 	// and returns a byte array containing any output/errors from the backend and
 	// if a reload was required.