Add handler path optional customisation w/ go mod support

Signed-off-by: Chris Reeves <hello@chris.reeves.io>

go.mod

@@ -0,0 +1,17 @@
+module github.com/krak3n/healthcheck
+
+go 1.12
+
+require (
+	github.com/beorn7/perks v0.0.0-20160804104726-4c0e84591b9a
+	github.com/davecgh/go-spew v1.1.0
+	github.com/golang/protobuf v1.0.0
+	github.com/matttproud/golang_protobuf_extensions v1.0.0
+	github.com/pmezard/go-difflib v1.0.0
+	github.com/prometheus/client_golang v0.0.0-20180223144718-c3324c1198cf
+	github.com/prometheus/client_model v0.0.0-20171117100541-99fa1f4be8e5
+	github.com/prometheus/common v0.0.0-20180228092548-6fb6fce6f8b7
+	github.com/prometheus/procfs v0.0.0-20180306113821-7186fbf4eb22
+	github.com/stretchr/testify v1.2.1
+	gopkg.in/DATA-DOG/go-sqlmock.v1 v1.3.0
+)

go.sum

@@ -0,0 +1,22 @@
+github.com/beorn7/perks v0.0.0-20160804104726-4c0e84591b9a h1:BtpsbiV638WQZwhA98cEZw2BsbnQJrbd0BI7tsy0W1c=
+github.com/beorn7/perks v0.0.0-20160804104726-4c0e84591b9a/go.mod h1:Dwedo/Wpr24TaqPxmxbtue+5NUziq4I4S80YR8gNf3Q=
+github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
+github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/golang/protobuf v1.0.0 h1:lsek0oXi8iFE9L+EXARyHIjU5rlWIhhTkjDz3vHhWWQ=
+github.com/golang/protobuf v1.0.0/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
+github.com/matttproud/golang_protobuf_extensions v1.0.0 h1:YNOwxxSJzSUARoD9KRZLzM9Y858MNGCOACTvCW9TSAc=
+github.com/matttproud/golang_protobuf_extensions v1.0.0/go.mod h1:D8He9yQNgCq6Z5Ld7szi9bcBfOoFv/3dc6xSMkL2PC0=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/prometheus/client_golang v0.0.0-20180223144718-c3324c1198cf h1:YtiXRsgYGXlAj+EHLMjLfsk5jrMpY/E3nmhIyUijV4E=
+github.com/prometheus/client_golang v0.0.0-20180223144718-c3324c1198cf/go.mod h1:7SWBe2y4D6OKWSNQJUaRYU/AaXPKyh/dDVn+NZz0KFw=
+github.com/prometheus/client_model v0.0.0-20171117100541-99fa1f4be8e5 h1:cLL6NowurKLMfCeQy4tIeph12XNQWgANCNvdyrOYKV4=
+github.com/prometheus/client_model v0.0.0-20171117100541-99fa1f4be8e5/go.mod h1:MbSGuTsp3dbXC40dX6PRTWyKYBIrTGTE9sqQNg2J8bo=
+github.com/prometheus/common v0.0.0-20180228092548-6fb6fce6f8b7 h1:M7FNIWkkGynttTfTsqQSWnhqzNS5ubqaXSJT7oGDfgI=
+github.com/prometheus/common v0.0.0-20180228092548-6fb6fce6f8b7/go.mod h1:daVV7qP5qjZbuso7PdcryaAu0sAZbrN9i7WWcTMWvro=
+github.com/prometheus/procfs v0.0.0-20180306113821-7186fbf4eb22 h1:jDQlbutSgD69Ul07voXv2yCaFilf4/jjNoUhmOIrR1k=
+github.com/prometheus/procfs v0.0.0-20180306113821-7186fbf4eb22/go.mod h1:c3At6R/oaqEKCNdg8wHV1ftS6bRYblBhIjjI8uT2IGk=
+github.com/stretchr/testify v1.2.1 h1:52QO5WkIUcHGIR7EnGagH88x1bUzqGXTC5/1bDTUQ7U=
+github.com/stretchr/testify v1.2.1/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXfy6kDkUVs=
+gopkg.in/DATA-DOG/go-sqlmock.v1 v1.3.0 h1:FVCohIoYO7IJoDDVpV2pdq7SgrMH6wHnuTyrdrxJNoY=
+gopkg.in/DATA-DOG/go-sqlmock.v1 v1.3.0/go.mod h1:OdE7CF6DbADk7lN8LIKRzRJTTZXIjtWgA5THM5lhBAw=

handler.go

@@ -20,6 +20,35 @@ import (
 	"sync"
 )
 
+// default configuration
+var defaultConfig = config{
+	LivenessPath:  "/live",
+	ReadinessPath: "/ready",
+}
+
+// handler configuration
+type config struct {
+	LivenessPath  string
+	ReadinessPath string
+}
+
+// A HandlerOption function can configure the healthcheck handler
+type HandlerOption func(c *config)
+
+// WithLivenessPath configures the liveness URL path
+func WithLivenessPath(p string) HandlerOption {
+	return func(c *config) {
+		c.LivenessPath = p
+	}
+}
+
+// WithReadinessPath configures the readiness URL path
+func WithReadinessPath(p string) HandlerOption {
+	return func(c *config) {
+		c.ReadinessPath = p
+	}
+}
+
 // basicHandler is a basic Handler implementation.
 type basicHandler struct {
 	http.ServeMux
@@ -29,13 +58,19 @@ type basicHandler struct {
 }
 
 // NewHandler creates a new basic Handler
-func NewHandler() Handler {
+func NewHandler(opts ...HandlerOption) Handler {
 	h := &basicHandler{
 		livenessChecks:  make(map[string]Check),
 		readinessChecks: make(map[string]Check),
 	}
-	h.Handle("/live", http.HandlerFunc(h.LiveEndpoint))
-	h.Handle("/ready", http.HandlerFunc(h.ReadyEndpoint))
+
+	cfg := defaultConfig
+	for _, opt := range opts {
+		opt(&cfg)
+	}
+
+	h.Handle(cfg.LivenessPath, http.HandlerFunc(h.LiveEndpoint))
+	h.Handle(cfg.ReadinessPath, http.HandlerFunc(h.ReadyEndpoint))
 	return h
 }
 

handler_test.go

@@ -28,6 +28,7 @@ func TestNewHandler(t *testing.T) {
 		name       string
 		method     string
 		path       string
+		opts       []HandlerOption
 		live       bool
 		ready      bool
 		expect     int
@@ -120,10 +121,33 @@ func TestNewHandler(t *testing.T) {
 			expect:     http.StatusServiceUnavailable,
 			expectBody: "{}\n",
 		},
+		{
+			name:       "with custom live path should succeed",
+			method:     "GET",
+			path:       "/_live",
+			opts:       []HandlerOption{WithLivenessPath("/_live")},
+			live:       true,
+			ready:      true,
+			expect:     http.StatusOK,
+			expectBody: "{}\n",
+		},
+		{
+			name:       "with custom ready path should succeed",
+			method:     "GET",
+			path:       "/_readiness",
+			opts:       []HandlerOption{WithLivenessPath("/_readiness")},
+			live:       true,
+			ready:      true,
+			expect:     http.StatusOK,
+			expectBody: "{}\n",
+		},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
 			h := NewHandler()
+			if tt.opts != nil {
+				h = NewHandler(tt.opts...)
+			}
 
 			if !tt.live {
 				h.AddLivenessCheck("test-liveness-check", func() error {