Added tests for health checks (#3)

health/dnsprobecheck_test.go

@@ -0,0 +1,13 @@
+package health
+
+import (
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestDNSProbeCheck(t *testing.T) {
+	assert.NoError(t, DNSProbeCheck("google.com", 5*time.Second)())
+	assert.Error(t, DNSProbeCheck("never.ever.where.com", 5*time.Second)())
+}

health/handler.go

@@ -61,10 +61,10 @@ func (ch *checksHandler) healthEndpoint(rw http.ResponseWriter, r *http.Request)
 }
 
 func (ch *checksHandler) readyEndpoint(rw http.ResponseWriter, r *http.Request) {
-	ch.handle(rw, r, ch.readinessChecks)
+	ch.handle(rw, r, ch.readinessChecks, ch.livenessChecks)
 }
 
-func (ch *checksHandler) handle(rw http.ResponseWriter, r *http.Request, checks map[string]Check) {
+func (ch *checksHandler) handle(rw http.ResponseWriter, r *http.Request, checksSets ...map[string]Check) {
 	if r.Method != http.MethodGet {
 		http.Error(rw, http.StatusText(http.StatusMethodNotAllowed), http.StatusMethodNotAllowed)
 		return
@@ -74,18 +74,22 @@ func (ch *checksHandler) handle(rw http.ResponseWriter, r *http.Request, checks
 	status := http.StatusOK
 	ch.lock.RLock()
 	defer ch.lock.RUnlock()
-	for name, check := range checks {
-		if check == nil {
-			continue
-		}
-		if err := check(); err != nil {
-			status = http.StatusServiceUnavailable
-			errors[name] = err
+
+	for _, checks := range checksSets {
+		for name, check := range checks {
+			if check == nil {
+				continue
+			}
+			if err := check(); err != nil {
+				status = http.StatusServiceUnavailable
+				errors[name] = err
+			}
 		}
 	}
-
 	rw.WriteHeader(status)
 
+	return
+
 	// Uncomment to write errors and get non-empty response
 	// rw.Header().Set("Content-Type", "application/json; charset=utf-8")
 	// if status == http.StatusOK {

health/handler_test.go

@@ -0,0 +1,107 @@
+package health
+
+import (
+	"errors"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestNewHandler(t *testing.T) {
+	var tests = []struct {
+		name         string
+		method       string
+		path         string
+		failHealth   bool
+		failReady    bool
+		expectedCode int
+	}{
+		{
+			name:         "Non-existent URL",
+			method:       http.MethodPost,
+			path:         "/neverwhere",
+			expectedCode: http.StatusNotFound,
+		},
+		{
+			name:         "POST Method not allowed health",
+			method:       http.MethodPost,
+			path:         "/healthz",
+			expectedCode: http.StatusMethodNotAllowed,
+		},
+		{
+			name:         "POST Method not allowed ready",
+			method:       http.MethodPost,
+			path:         "/ready",
+			expectedCode: http.StatusMethodNotAllowed,
+		},
+		{
+			name:         "No checks health",
+			method:       http.MethodGet,
+			path:         "/healthz",
+			expectedCode: http.StatusOK,
+		},
+		{
+			name:         "No checks ready",
+			method:       http.MethodGet,
+			path:         "/ready",
+			expectedCode: http.StatusOK,
+		},
+		{
+			name:         "Health succeed Ready fail health",
+			method:       http.MethodGet,
+			path:         "/healthz",
+			expectedCode: http.StatusOK,
+			failReady:    true,
+		},
+		{
+			name:         "Health succeed Ready fail ready",
+			method:       http.MethodGet,
+			path:         "/ready",
+			expectedCode: http.StatusServiceUnavailable,
+			failReady:    true,
+		},
+		{
+			name:         "Health fail Ready succeed health",
+			method:       http.MethodGet,
+			path:         "/healthz",
+			expectedCode: http.StatusServiceUnavailable,
+			failHealth:   true,
+		},
+		{
+			name:         "Health fail Ready succeed ready",
+			method:       http.MethodGet,
+			path:         "/ready",
+			expectedCode: http.StatusServiceUnavailable,
+			failHealth:   true,
+		},
+	}
+
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			h := NewChecksHandler("/healthz", "/ready")
+
+			if test.failHealth {
+				h.AddLiveness("Liveness check test", func() error {
+					return errors.New("Liveness check failed")
+				})
+			}
+
+			if test.failReady {
+				h.AddReadiness("Readiness check test", func() error {
+					return errors.New("Readiness check failed")
+				})
+			}
+
+			req, err := http.NewRequest(test.method, test.path, nil)
+			assert.NoError(t, err)
+
+			reqStr := test.method + " " + test.path
+			httpRecorder := httptest.NewRecorder()
+			h.Handler().ServeHTTP(httpRecorder, req)
+			assert.Equal(t, test.expectedCode, httpRecorder.Code,
+				"Result codes don't match %q. [%s]", reqStr, test.name)
+		})
+	}
+}

health/httpgetcheck_test.go

@@ -0,0 +1,14 @@
+package health
+
+import (
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestHTTPGetCheck(t *testing.T) {
+	assert.NoError(t, HTTPGetCheck("http://httpbin.org/get", 5*time.Second)(), "Simple HTTP GET request shouldn't fail")
+	assert.Error(t, HTTPGetCheck("http://httpbin.org/relative-redirect/:1", 5*time.Second)(), "Redirrect is not HTTP 200: OK")
+	assert.Error(t, HTTPGetCheck("http://httpbin.org/nonexistent", 5*time.Second)(), "Non-existing site exists")
+}