VOL-1723 - add readiness probe capability to rw-core

Change-Id: I1cf42e88712586f140a2dfa9d0b638b48261caac
diff --git a/common/probe/probe_test.go b/common/probe/probe_test.go
new file mode 100644
index 0000000..18c4835
--- /dev/null
+++ b/common/probe/probe_test.go
@@ -0,0 +1,372 @@
+/*
+ * Copyright 2019-present Open Networking Foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package probe
+
+import (
+	"context"
+	"encoding/json"
+	"github.com/opencord/voltha-go/common/log"
+	"github.com/stretchr/testify/assert"
+	"io/ioutil"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+)
+
+func init() {
+	log.AddPackage(log.JSON, log.WarnLevel, nil)
+}
+
+func TestServiceStatusString(t *testing.T) {
+	assert.Equal(t, "Unknown", ServiceStatusUnknown.String(), "ServiceStatusUnknown")
+	assert.Equal(t, "Preparing", ServiceStatusPreparing.String(), "ServiceStatusPreparing")
+	assert.Equal(t, "Prepared", ServiceStatusPrepared.String(), "ServiceStatusPrepared")
+	assert.Equal(t, "Running", ServiceStatusRunning.String(), "ServiceStatusRunning")
+	assert.Equal(t, "Stopped", ServiceStatusStopped.String(), "ServiceStatusStopped")
+	assert.Equal(t, "Failed", ServiceStatusFailed.String(), "ServiceStatusFailed")
+}
+
+func AlwaysTrue(map[string]ServiceStatus) bool {
+	return true
+}
+
+func AlwaysFalse(map[string]ServiceStatus) bool {
+	return false
+}
+
+func TestWithFuncs(t *testing.T) {
+	p := (&Probe{}).WithReadyFunc(AlwaysTrue).WithHealthFunc(AlwaysFalse)
+
+	assert.NotNil(t, p.readyFunc, "ready func not set")
+	assert.True(t, p.readyFunc(nil), "ready func not set correctly")
+	assert.NotNil(t, p.healthFunc, "health func not set")
+	assert.False(t, p.healthFunc(nil), "health func not set correctly")
+}
+
+func TestWithReadyFuncOnly(t *testing.T) {
+	p := (&Probe{}).WithReadyFunc(AlwaysTrue)
+
+	assert.NotNil(t, p.readyFunc, "ready func not set")
+	assert.True(t, p.readyFunc(nil), "ready func not set correctly")
+	assert.Nil(t, p.healthFunc, "health func set")
+}
+
+func TestWithHealthFuncOnly(t *testing.T) {
+	p := (&Probe{}).WithHealthFunc(AlwaysTrue)
+
+	assert.Nil(t, p.readyFunc, "ready func set")
+	assert.NotNil(t, p.healthFunc, "health func not set")
+	assert.True(t, p.healthFunc(nil), "health func not set correctly")
+}
+
+func TestRegisterOneService(t *testing.T) {
+	p := &Probe{}
+
+	p.RegisterService("one")
+
+	assert.Equal(t, 1, len(p.status), "wrong number of services")
+
+	_, ok := p.status["one"]
+	assert.True(t, ok, "service not found")
+}
+
+func TestRegisterMultipleServices(t *testing.T) {
+	p := &Probe{}
+
+	p.RegisterService("one", "two", "three", "four")
+
+	assert.Equal(t, 4, len(p.status), "wrong number of services")
+
+	_, ok := p.status["one"]
+	assert.True(t, ok, "service one not found")
+	_, ok = p.status["two"]
+	assert.True(t, ok, "service two not found")
+	_, ok = p.status["three"]
+	assert.True(t, ok, "service three not found")
+	_, ok = p.status["four"]
+	assert.True(t, ok, "service four not found")
+}
+
+func TestRegisterMultipleServicesIncremental(t *testing.T) {
+	p := &Probe{}
+
+	p.RegisterService("one")
+	p.RegisterService("two")
+	p.RegisterService("three", "four")
+
+	assert.Equal(t, 4, len(p.status), "wrong number of services")
+
+	_, ok := p.status["one"]
+	assert.True(t, ok, "service one not found")
+	_, ok = p.status["two"]
+	assert.True(t, ok, "service two not found")
+	_, ok = p.status["three"]
+	assert.True(t, ok, "service three not found")
+	_, ok = p.status["four"]
+	assert.True(t, ok, "service four not found")
+}
+
+func TestRegisterMultipleServicesDuplicates(t *testing.T) {
+	p := &Probe{}
+
+	p.RegisterService("one", "one", "one", "two")
+
+	assert.Equal(t, 2, len(p.status), "wrong number of services")
+
+	_, ok := p.status["one"]
+	assert.True(t, ok, "service one not found")
+	_, ok = p.status["two"]
+	assert.True(t, ok, "service two not found")
+}
+
+func TestRegisterMultipleServicesDuplicatesIncremental(t *testing.T) {
+	p := &Probe{}
+
+	p.RegisterService("one")
+	p.RegisterService("one")
+	p.RegisterService("one", "two")
+
+	assert.Equal(t, 2, len(p.status), "wrong number of services")
+
+	_, ok := p.status["one"]
+	assert.True(t, ok, "service one not found")
+	_, ok = p.status["two"]
+	assert.True(t, ok, "service two not found")
+}
+
+func TestUpdateStatus(t *testing.T) {
+	p := &Probe{}
+
+	p.RegisterService("one", "two")
+	p.UpdateStatus("one", ServiceStatusRunning)
+
+	assert.Equal(t, ServiceStatusRunning, p.status["one"], "status not set")
+	assert.Equal(t, ServiceStatusUnknown, p.status["two"], "status set")
+}
+
+func TestRegisterOverwriteStatus(t *testing.T) {
+	p := &Probe{}
+
+	p.RegisterService("one", "two")
+	p.UpdateStatus("one", ServiceStatusRunning)
+
+	assert.Equal(t, ServiceStatusRunning, p.status["one"], "status not set")
+	assert.Equal(t, ServiceStatusUnknown, p.status["two"], "status set")
+
+	p.RegisterService("one", "three")
+	assert.Equal(t, 3, len(p.status), "wrong number of services")
+	assert.Equal(t, ServiceStatusRunning, p.status["one"], "status overridden")
+	assert.Equal(t, ServiceStatusUnknown, p.status["two"], "status set")
+	assert.Equal(t, ServiceStatusUnknown, p.status["three"], "status set")
+}
+
+func TestDetailzWithServies(t *testing.T) {
+	p := (&Probe{}).WithReadyFunc(AlwaysTrue).WithHealthFunc(AlwaysTrue)
+	p.RegisterService("one", "two")
+
+	req := httptest.NewRequest("GET", "http://example.com/detailz", nil)
+	w := httptest.NewRecorder()
+	p.detailzFunc(w, req)
+	resp := w.Result()
+	body, _ := ioutil.ReadAll(resp.Body)
+
+	assert.Equal(t, http.StatusOK, resp.StatusCode, "invalid status code for no services")
+	assert.Equal(t, "application/json", resp.Header.Get("Content-Type"), "wrong content type")
+	var vals map[string]string
+	err := json.Unmarshal(body, &vals)
+	assert.Nil(t, err, "unable to unmarshal values")
+	assert.Equal(t, "Unknown", vals["one"], "wrong value")
+	assert.Equal(t, "Unknown", vals["two"], "wrong value")
+}
+
+func TestReadzNoServices(t *testing.T) {
+	p := (&Probe{}).WithReadyFunc(AlwaysTrue)
+	req := httptest.NewRequest("GET", "http://example.com/readz", nil)
+	w := httptest.NewRecorder()
+	p.readzFunc(w, req)
+	resp := w.Result()
+
+	assert.Equal(t, http.StatusTeapot, resp.StatusCode, "invalid status code for no services")
+}
+
+func TestReadzWithServices(t *testing.T) {
+	p := (&Probe{}).WithReadyFunc(AlwaysTrue).WithHealthFunc(AlwaysTrue)
+	p.RegisterService("one", "two")
+
+	req := httptest.NewRequest("GET", "http://example.com/readz", nil)
+	w := httptest.NewRecorder()
+	p.readzFunc(w, req)
+	resp := w.Result()
+	assert.Equal(t, http.StatusTeapot, resp.StatusCode, "invalid status code for no services")
+}
+
+func TestReadzNpServicesDefault(t *testing.T) {
+	p := &Probe{}
+
+	req := httptest.NewRequest("GET", "http://example.com/readz", nil)
+	w := httptest.NewRecorder()
+	p.readzFunc(w, req)
+	resp := w.Result()
+	assert.Equal(t, http.StatusTeapot, resp.StatusCode, "invalid status code")
+}
+
+func TestReadzWithServicesDefault(t *testing.T) {
+	p := &Probe{}
+	p.RegisterService("one", "two")
+	p.UpdateStatus("one", ServiceStatusRunning)
+	p.UpdateStatus("two", ServiceStatusRunning)
+
+	req := httptest.NewRequest("GET", "http://example.com/readz", nil)
+	w := httptest.NewRecorder()
+	p.readzFunc(w, req)
+	resp := w.Result()
+	assert.Equal(t, http.StatusOK, resp.StatusCode, "invalid status code")
+}
+
+func TestReadzWithServicesDefaultOne(t *testing.T) {
+	p := &Probe{}
+	p.RegisterService("one", "two")
+	p.UpdateStatus("one", ServiceStatusRunning)
+
+	req := httptest.NewRequest("GET", "http://example.com/readz", nil)
+	w := httptest.NewRecorder()
+	p.readzFunc(w, req)
+	resp := w.Result()
+	assert.Equal(t, http.StatusTeapot, resp.StatusCode, "invalid status code")
+}
+
+func TestHealthzNoServices(t *testing.T) {
+	p := (&Probe{}).WithReadyFunc(AlwaysTrue)
+	req := httptest.NewRequest("GET", "http://example.com/healthz", nil)
+	w := httptest.NewRecorder()
+	p.healthzFunc(w, req)
+	resp := w.Result()
+
+	assert.Equal(t, http.StatusTeapot, resp.StatusCode, "invalid status code for no services")
+}
+
+func TestHealthzWithServices(t *testing.T) {
+	p := (&Probe{}).WithReadyFunc(AlwaysTrue).WithHealthFunc(AlwaysTrue)
+	p.RegisterService("one", "two")
+
+	req := httptest.NewRequest("GET", "http://example.com/healthz", nil)
+	w := httptest.NewRecorder()
+	p.healthzFunc(w, req)
+	resp := w.Result()
+	assert.Equal(t, http.StatusTeapot, resp.StatusCode, "invalid status code for no services")
+}
+
+func TestHealthzNoServicesDefault(t *testing.T) {
+	p := &Probe{}
+
+	req := httptest.NewRequest("GET", "http://example.com/healthz", nil)
+	w := httptest.NewRecorder()
+	p.healthzFunc(w, req)
+	resp := w.Result()
+	assert.Equal(t, http.StatusTeapot, resp.StatusCode, "invalid status code")
+}
+
+func TestHealthzWithServicesDefault(t *testing.T) {
+	p := &Probe{}
+	p.RegisterService("one", "two")
+	p.UpdateStatus("one", ServiceStatusRunning)
+	p.UpdateStatus("two", ServiceStatusRunning)
+
+	req := httptest.NewRequest("GET", "http://example.com/healthz", nil)
+	w := httptest.NewRecorder()
+	p.healthzFunc(w, req)
+	resp := w.Result()
+	assert.Equal(t, http.StatusOK, resp.StatusCode, "invalid status code")
+}
+
+func TestHealthzWithServicesDefaultFailed(t *testing.T) {
+	p := &Probe{}
+	p.RegisterService("one", "two")
+	p.UpdateStatus("one", ServiceStatusFailed)
+
+	req := httptest.NewRequest("GET", "http://example.com/healthz", nil)
+	w := httptest.NewRecorder()
+	p.healthzFunc(w, req)
+	resp := w.Result()
+	assert.Equal(t, http.StatusTeapot, resp.StatusCode, "invalid status code")
+}
+
+func TestSetFuncsToNil(t *testing.T) {
+	p := (&Probe{}).WithReadyFunc(AlwaysTrue).WithHealthFunc(AlwaysFalse)
+	p.WithReadyFunc(nil).WithHealthFunc(nil)
+	assert.Nil(t, p.readyFunc, "ready func not reset to nil")
+	assert.Nil(t, p.healthFunc, "health func not reset to nil")
+}
+
+func TestUpdateStatusFromContext(t *testing.T) {
+	p := &Probe{}
+	p.RegisterService("one")
+	ctx := context.WithValue(context.Background(), ProbeContextKey, p)
+	UpdateStatusFromContext(ctx, "one", ServiceStatusRunning)
+
+	assert.Equal(t, 1, len(p.status), "wrong number of services")
+	_, ok := p.status["one"]
+	assert.True(t, ok, "unable to find registered service")
+	assert.Equal(t, ServiceStatusRunning, p.status["one"], "status not set correctly from context")
+
+}
+
+func TestUpdateStatusFromNilContext(t *testing.T) {
+	p := &Probe{}
+	p.RegisterService("one")
+	UpdateStatusFromContext(nil, "one", ServiceStatusRunning)
+
+	assert.Equal(t, 1, len(p.status), "wrong number of services")
+	_, ok := p.status["one"]
+	assert.True(t, ok, "unable to find registered service")
+	assert.Equal(t, ServiceStatusUnknown, p.status["one"], "status not set correctly from context")
+
+}
+
+func TestUpdateStatusFromContextWithoutProbe(t *testing.T) {
+	p := &Probe{}
+	p.RegisterService("one")
+	ctx := context.Background()
+	UpdateStatusFromContext(ctx, "one", ServiceStatusRunning)
+
+	assert.Equal(t, 1, len(p.status), "wrong number of services")
+	_, ok := p.status["one"]
+	assert.True(t, ok, "unable to find registered service")
+	assert.Equal(t, ServiceStatusUnknown, p.status["one"], "status not set correctly from context")
+
+}
+
+func TestUpdateStatusFromContextWrongType(t *testing.T) {
+	p := &Probe{}
+	p.RegisterService("one")
+	ctx := context.WithValue(context.Background(), ProbeContextKey, "Teapot")
+	UpdateStatusFromContext(ctx, "one", ServiceStatusRunning)
+
+	assert.Equal(t, 1, len(p.status), "wrong number of services")
+	_, ok := p.status["one"]
+	assert.True(t, ok, "unable to find registered service")
+	assert.Equal(t, ServiceStatusUnknown, p.status["one"], "status not set correctly from context")
+}
+
+func TestUpdateStatusNoRegistered(t *testing.T) {
+	p := (&Probe{}).WithReadyFunc(AlwaysTrue).WithHealthFunc(AlwaysFalse)
+
+	p.UpdateStatus("one", ServiceStatusRunning)
+	assert.Equal(t, 1, len(p.status), "wrong number of services")
+	_, ok := p.status["one"]
+	assert.True(t, ok, "unable to find registered service")
+	assert.Equal(t, ServiceStatusRunning, p.status["one"], "status not set correctly from context")
+}