refactor(kubeprobes): refactor code

- refactored types, interfaces, options etc.
- added new options dedicated for `StatefulProbe`s

costants.go

@@ -0,0 +1,7 @@
+package kubeprobes
+
+const (
+	defaultLivenessPath  string = "/live"
+	defaultReadinessPath string = "/ready"
+	verboseOutputFlag    string = "v"
+)

options.go

@@ -0,0 +1,67 @@
+package kubeprobes
+
+type option struct {
+	fn func(*kubeprobes)
+}
+
+func (o *option) apply(kp *kubeprobes) {
+	o.fn(kp)
+}
+
+// WithLivenessProbes adds given probe functions to the set of liveness probes.
+func WithLivenessProbes(probes ...ProbeFunction) Option {
+	return &option{
+		fn: func(kp *kubeprobes) {
+			kp.livenessProbes = append(kp.livenessProbes, probes...)
+		},
+	}
+}
+
+// WithLivenessStatefulProbes adds given [StatefulProbe]s to the set of liveness probes.
+func WithLivenessStatefulProbes(probes ...*StatefulProbe) Option {
+	return &option{
+		fn: func(kp *kubeprobes) {
+			for _, p := range probes {
+				kp.livenessProbes = append(kp.livenessProbes, p.GetProbeFunction())
+			}
+		},
+	}
+}
+
+// WithLivenessPath sets custom path for liveness probe (default is "/live").
+func WithLivenessPath(path string) Option {
+	return &option{
+		fn: func(kp *kubeprobes) {
+			kp.pathLive = path
+		},
+	}
+}
+
+// WithReadinessProbes adds given probe functions to the set of readiness probes.
+func WithReadinessProbes(probes ...ProbeFunction) Option {
+	return &option{
+		fn: func(kp *kubeprobes) {
+			kp.readinessProbes = append(kp.readinessProbes, probes...)
+		},
+	}
+}
+
+// WithReadinessProbes adds given [StatefulProbe]s to the set of readiness probes.
+func WithReadinessStatefulProbes(probes ...*StatefulProbe) Option {
+	return &option{
+		fn: func(kp *kubeprobes) {
+			for _, p := range probes {
+				kp.readinessProbes = append(kp.readinessProbes, p.GetProbeFunction())
+			}
+		},
+	}
+}
+
+// WithReadinessPath sets custom path for readiness probe (default is "/ready").
+func WithReadinessPath(path string) Option {
+	return &option{
+		fn: func(kp *kubeprobes) {
+			kp.pathReady = path
+		},
+	}
+}

probes.go

@@ -1,6 +1,8 @@
 package kubeprobes
 
 import (
+	"errors"
+	"fmt"
 	"net/http"
 	"strings"
 )
@@ -8,57 +10,97 @@ import (
 type kubeprobes struct {
 	livenessProbes  []ProbeFunction
 	readinessProbes []ProbeFunction
+
+	pathLive  string
+	pathReady string
 }
 
-// ServeHTTP implements http.Handler interface
+// New returns a new instance of a Kubernetes probes with given options.
+func New(options ...Option) (Kubeprobes, error) {
+	kp := &kubeprobes{
+		livenessProbes:  []ProbeFunction{},
+		readinessProbes: []ProbeFunction{},
+		pathLive:        "/live",
+		pathReady:       "/ready",
+	}
+
+	for _, option := range options {
+		option.apply(kp)
+	}
+
+	if err := kp.validate(); err != nil {
+		return nil, err
+	}
+	return kp, nil
+}
+
+func (kp *kubeprobes) validate() error {
+	errs := []error{}
+
+	if kp.pathLive == "" {
+		errs = append(
+			errs,
+			fmt.Errorf("liveness probe path must not be empty"),
+		)
+	}
+
+	if kp.pathReady == "" {
+		errs = append(
+			errs,
+			fmt.Errorf("readiness probe path must not be empty"),
+		)
+	}
+
+	if !strings.HasPrefix(kp.pathLive, "/") {
+		errs = append(
+			errs,
+			fmt.Errorf("liveness probe path must start with slash (current: %q)", kp.pathLive),
+		)
+	}
+
+	if !strings.HasPrefix(kp.pathReady, "/") {
+		errs = append(
+			errs,
+			fmt.Errorf("readiness probe path must start with slash (current: %q)", kp.pathReady),
+		)
+	}
+
+	if kp.pathLive == kp.pathReady {
+		errs = append(
+			errs,
+			fmt.Errorf("liveness and readiness probes have the same values (both %q)", kp.pathLive),
+		)
+	}
+
+	return errors.Join(errs...)
+}
+
+func (kp *kubeprobes) handleLiveness(w http.ResponseWriter, _ *http.Request) {
+	sq := newStatusQuery(kp.livenessProbes)
+	if sq.isAllGreen() {
+		w.WriteHeader(http.StatusOK)
+	} else {
+		w.WriteHeader(http.StatusServiceUnavailable)
+	}
+}
+
+func (kp *kubeprobes) handleReadiness(w http.ResponseWriter, _ *http.Request) {
+	sq := newStatusQuery(append(kp.livenessProbes, kp.readinessProbes...))
+	if sq.isAllGreen() {
+		w.WriteHeader(http.StatusOK)
+	} else {
+		w.WriteHeader(http.StatusServiceUnavailable)
+	}
+}
+
+// ServeHTTP implements Kubeprobes.
 func (kp *kubeprobes) ServeHTTP(w http.ResponseWriter, r *http.Request) {
-	subs := strings.Split(strings.TrimSuffix(r.URL.Path, "/"), "/")
-	switch subs[len(subs)-1] {
-	case "live":
-		sq := newStatusQuery(kp.livenessProbes)
-		if sq.isAllGreen() {
-			w.WriteHeader(http.StatusOK)
-		} else {
-			w.WriteHeader(http.StatusServiceUnavailable)
-		}
-	case "ready":
-		sq := newStatusQuery(append(kp.livenessProbes, kp.readinessProbes...))
-		if sq.isAllGreen() {
-			w.WriteHeader(http.StatusOK)
-		} else {
-			w.WriteHeader(http.StatusServiceUnavailable)
-		}
+	switch r.URL.Path {
+	case kp.pathLive:
+		kp.handleLiveness(w, r)
+	case kp.pathReady:
+		kp.handleReadiness(w, r)
 	default:
 		w.WriteHeader(http.StatusNotFound)
 	}
 }
-
-type option func(*kubeprobes)
-
-// New returns a new instance of a Kubernetes probes
-func New(options ...option) *kubeprobes {
-	kp := &kubeprobes{
-		livenessProbes:  []ProbeFunction{},
-		readinessProbes: []ProbeFunction{},
-	}
-
-	for _, option := range options {
-		option(kp)
-	}
-
-	return kp
-}
-
-// WithLivenessProbes adds given liveness probes to the set of probes
-func WithLivenessProbes(probes ...ProbeFunction) option {
-	return func(kp *kubeprobes) {
-		kp.livenessProbes = append(kp.livenessProbes, probes...)
-	}
-}
-
-// WithReadinessProbes adds given readiness probes to the set of probes
-func WithReadinessProbes(probes ...ProbeFunction) option {
-	return func(kp *kubeprobes) {
-		kp.readinessProbes = append(kp.readinessProbes, probes...)
-	}
-}

probes_test.go

@@ -50,9 +50,9 @@ func TestKubeprobes(t *testing.T) {
 		},
 	}
 
-	kp := New(
-		WithLivenessProbes(live.GetProbeFunction()),
-		WithReadinessProbes(ready.GetProbeFunction()),
+	kp, _ := New(
+		WithLivenessStatefulProbes(live),
+		WithReadinessStatefulProbes(ready),
 	)
 
 	srv := httptest.NewServer(kp)
@@ -65,8 +65,8 @@ func TestKubeprobes(t *testing.T) {
 			test.livenessProbeTransformation(t, live)
 			test.readinessProbeTransformation(t, ready)
 
-			liveStatus := getStatusFromEndpoint(t, client, srv.URL+"/live")
-			readyStatus := getStatusFromEndpoint(t, client, srv.URL+"/ready")
+			liveStatus := getStatusFromEndpoint(t, client, srv.URL+defaultLivenessPath)
+			readyStatus := getStatusFromEndpoint(t, client, srv.URL+defaultReadinessPath)
 			otherStatus := getStatusFromEndpoint(t, client, srv.URL+"/something")
 
 			if liveStatus != test.expectedLiveStatus {

query.go

@@ -2,11 +2,6 @@ package kubeprobes
 
 import "sync"
 
-// ProbeFunction is a function that determines whether
-// the given metric may be marked as correctly functioning.
-// It not, the error should be returned.
-type ProbeFunction func() error
-
 type statusQuery struct {
 	allGreen bool
 	mux      sync.Mutex

stateful_probe.go

@@ -5,13 +5,13 @@ import (
 	"sync"
 )
 
-var errProbeDown = errors.New("DOWN")
+var errProbeDown = errors.New("probe is down")
 
 // StatefulProbe represents the simple probe that can be either
 // marked as "up" (healthy) or "down" (unhealthy).
 type StatefulProbe struct {
-	status bool
 	mux    sync.Mutex
+	status bool
 }
 
 // NewStatefulProbe returns a new instance of a stateful probe
@@ -19,19 +19,19 @@ type StatefulProbe struct {
 // The probe is initially marked as "down".
 func NewStatefulProbe() *StatefulProbe {
 	return &StatefulProbe{
-		status: false,
 		mux:    sync.Mutex{},
+		status: false,
 	}
 }
 
-// MarkAsUp marks the probe as healthy
+// MarkAsUp marks the probe as healthy.
 func (sp *StatefulProbe) MarkAsUp() {
 	sp.mux.Lock()
 	defer sp.mux.Unlock()
 	sp.status = true
 }
 
-// MarkAsDown marks the probe as unhealthy
+// MarkAsDown marks the probe as unhealthy.
 func (sp *StatefulProbe) MarkAsDown() {
 	sp.mux.Lock()
 	defer sp.mux.Unlock()

types.go

@@ -0,0 +1,18 @@
+package kubeprobes
+
+import "net/http"
+
+// Kubeprobes represents liveness & readiness probes handler.
+type Kubeprobes interface {
+	http.Handler
+}
+
+// Option represents a [Kubeprobes] constructor option.
+type Option interface {
+	apply(kp *kubeprobes)
+}
+
+// ProbeFunction is a function that determines whether
+// the given metric may be marked as correctly functioning.
+// It not, the error should be returned.
+type ProbeFunction func() error