Refactor configapi to use new cache

internal/cache/cache.go

@@ -1,6 +1,16 @@
 package cache
 
-import "time"
+import (
+	"errors"
+	"time"
+)
+
+var (
+	// NoTTL define an entry that lives forever
+	NoTTL = time.Duration(-1)
+	// ErrNIL is returned when there's no value for given key
+	ErrNIL = errors.New("value is nil")
+)
 
 //go:generate mockgen -destination=../cache_mock/cache_mock.go -package=cache_mock . Cache
 

internal/configapi/configapi.go

@@ -2,10 +2,9 @@ package configapi
 
 import (
 	"fmt"
-	"github.com/creekorful/trandoshan/internal/configapi/database"
+	"github.com/creekorful/trandoshan/internal/cache"
 	"github.com/creekorful/trandoshan/internal/event"
 	"github.com/creekorful/trandoshan/internal/process"
-	"github.com/go-redis/redis/v8"
 	"github.com/gorilla/mux"
 	"github.com/rs/zerolog/log"
 	"github.com/urfave/cli/v2"
@@ -16,8 +15,8 @@ import (
 
 // State represent the application state
 type State struct {
-	db  database.Database
-	pub event.Publisher
+	configCache cache.Cache
+	pub         event.Publisher
 }
 
 // Name return the process name
@@ -47,11 +46,7 @@ func (state *State) CustomFlags() []cli.Flag {
 
 // Initialize the process
 func (state *State) Initialize(provider process.Provider) error {
-	db, err := database.NewRedisDatabase(provider.GetValue("db-uri"))
-	if err != nil {
-		return err
-	}
-	state.db = db
+	// TODO init cache
 
 	pub, err := provider.Publisher()
 	if err != nil {
@@ -68,7 +63,7 @@ func (state *State) Initialize(provider process.Provider) error {
 		}
 	}
 	if len(defaultValues) > 0 {
-		if err := setDefaultValues(db, defaultValues); err != nil {
+		if err := setDefaultValues(nil, defaultValues); err != nil {
 			return err
 		}
 	}
@@ -96,7 +91,7 @@ func (state *State) getConfiguration(w http.ResponseWriter, r *http.Request) {
 
 	log.Debug().Str("key", key).Msg("Getting key")
 
-	b, err := state.db.Get(key)
+	b, err := state.configCache.GetBytes(key)
 	if err != nil {
 		log.Err(err).Msg("error while retrieving configuration")
 		w.WriteHeader(http.StatusInternalServerError)
@@ -120,7 +115,7 @@ func (state *State) setConfiguration(w http.ResponseWriter, r *http.Request) {
 
 	log.Debug().Str("key", key).Bytes("value", b).Msg("Setting key")
 
-	if err := state.db.Set(key, b); err != nil {
+	if err := state.configCache.SetBytes(key, b, cache.NoTTL); err != nil {
 		log.Err(err).Msg("error while setting configuration")
 		w.WriteHeader(http.StatusInternalServerError)
 		return
@@ -139,10 +134,10 @@ func (state *State) setConfiguration(w http.ResponseWriter, r *http.Request) {
 	_, _ = w.Write(b)
 }
 
-func setDefaultValues(service database.Database, values map[string]string) error {
+func setDefaultValues(configCache cache.Cache, values map[string]string) error {
 	for key, value := range values {
-		if _, err := service.Get(key); err == redis.Nil {
-			if err := service.Set(key, []byte(value)); err != nil {
+		if _, err := configCache.GetBytes(key); err == cache.ErrNIL {
+			if err := configCache.SetBytes(key, []byte(value), cache.NoTTL); err != nil {
 				return fmt.Errorf("error while setting default value of %s: %s", key, err)
 			}
 		}

internal/configapi/configapi_test.go

@@ -1,7 +1,8 @@
 package configapi
 
 import (
-	"github.com/creekorful/trandoshan/internal/configapi/database_mock"
+	"github.com/creekorful/trandoshan/internal/cache"
+	"github.com/creekorful/trandoshan/internal/cache_mock"
 	"github.com/creekorful/trandoshan/internal/event"
 	"github.com/creekorful/trandoshan/internal/event_mock"
 	"github.com/golang/mock/gomock"
@@ -17,15 +18,15 @@ func TestGetConfiguration(t *testing.T) {
 	mockCtrl := gomock.NewController(t)
 	defer mockCtrl.Finish()
 
-	dbMock := database_mock.NewMockDatabase(mockCtrl)
-	dbMock.EXPECT().Get("hello").Return([]byte("{\"ttl\": \"10s\"}"), nil)
+	configCacheMock := cache_mock.NewMockCache(mockCtrl)
+	configCacheMock.EXPECT().GetBytes("hello").Return([]byte("{\"ttl\": \"10s\"}"), nil)
 
 	req := httptest.NewRequest(http.MethodGet, "/config/hello", nil)
 	req = mux.SetURLVars(req, map[string]string{"key": "hello"})
 
 	rec := httptest.NewRecorder()
 
-	s := State{db: dbMock}
+	s := State{configCache: configCacheMock}
 	s.getConfiguration(rec, req)
 
 	if rec.Code != http.StatusOK {
@@ -49,10 +50,10 @@ func TestSetConfiguration(t *testing.T) {
 	mockCtrl := gomock.NewController(t)
 	defer mockCtrl.Finish()
 
-	dbMock := database_mock.NewMockDatabase(mockCtrl)
+	configCacheMock := cache_mock.NewMockCache(mockCtrl)
 	pubMock := event_mock.NewMockPublisher(mockCtrl)
 
-	dbMock.EXPECT().Set("hello", []byte("{\"ttl\": \"10s\"}")).Return(nil)
+	configCacheMock.EXPECT().SetBytes("hello", []byte("{\"ttl\": \"10s\"}"), cache.NoTTL).Return(nil)
 	pubMock.EXPECT().PublishJSON("config", event.RawMessage{
 		Body:    []byte("{\"ttl\": \"10s\"}"),
 		Headers: map[string]interface{}{"Config-Key": "hello"},
@@ -63,7 +64,7 @@ func TestSetConfiguration(t *testing.T) {
 
 	rec := httptest.NewRecorder()
 
-	s := State{db: dbMock, pub: pubMock}
+	s := State{configCache: configCacheMock, pub: pubMock}
 	s.setConfiguration(rec, req)
 
 	if rec.Code != http.StatusOK {

internal/configapi/database/database.go

@@ -1,9 +0,0 @@
-package database
-
-//go:generate mockgen -destination=../database_mock/database_mock.go -package=database_mock . Database
-
-// Database is the underlying storage for the ConfigAPI
-type Database interface {
-	Get(key string) ([]byte, error)
-	Set(key string, value []byte) error
-}

internal/configapi/database/redis.go

@@ -1,29 +0,0 @@
-package database
-
-import (
-	"context"
-	"github.com/go-redis/redis/v8"
-)
-
-type redisDatabase struct {
-	rc *redis.Client
-}
-
-// NewRedisDatabase returns a new database that use Redis as backend
-func NewRedisDatabase(uri string) (Database, error) {
-	return &redisDatabase{
-		rc: redis.NewClient(&redis.Options{
-			Addr:     uri,
-			Password: "", // no password set
-			DB:       0,  // use default DB
-		}),
-	}, nil
-}
-
-func (rd *redisDatabase) Get(key string) ([]byte, error) {
-	return rd.rc.Get(context.Background(), key).Bytes()
-}
-
-func (rd *redisDatabase) Set(key string, value []byte) error {
-	return rd.rc.Set(context.Background(), key, value, 0).Err()
-}