Minor refactor tackling typos, overhauling README, adding hints about useful resources to README, and avoid any panic/Fatalf from services and init calls #noissue

Makefile

@@ -55,10 +55,7 @@ checkstyle:
 
 checkstyle-ci: checkstyle
 
-checkstyle-ci:
-	go vet ./...
-
 test:
-	go test ./...
+	go test -race ./...
 
 test-ci: test

README.md

@@ -12,15 +12,7 @@ Contributions are very welcome!
 
 ## Development & contribution
 
-* Ensure to set the following environment variables for proper debug logs during development
-
-```shell
-DEVELOPMENT=true
-LOGGING_ENCODING=console
-LOGGING_LEVEL=debug
-```
-
-* Code guidelines
+* Pay attention to `make checkstyle` (uses `go vet ./...`); pipeline fails if issues are detected.
 * Each entity has its own repository
 * Each entity is only used in repository and service (otherwise, mapping happens)
 * Presenter layer is constructed from the entity, e.g., in REST responses and mapped
@@ -28,47 +20,30 @@ LOGGING_LEVEL=debug
 * All log calls should be handled by `zap.L()`
 * Configuration is bootstrapped via separated `struct` types which are given to the service which need them
 * Error handling
-        * Always throw an error with `NewServiceError`
-        * Always wrap the cause error with `fmt.Errorf`
+    * Always throw an error with `NewServiceError` for repositories, services and handlers
+    * Always throw an error wrapping the cause with `fmt.Errorf`
     * Forward/bubble up the error directly, when original error is already a `NewServiceError` (most likely internal
       calls)
     * Always abort handler chain with `AbortWithError`
     * Utils can throw any error
-
-Please look into the `_doc/` folder for [OpenAPI specification](./_doc/api.yaml) and a Postman Collection.
-
-**Pay attention to `make checkstyle` (invoked `go vet ./...`) output as pipeline will fail if issues are detected.**
-
-### Lock service
-
-The `lockService` can be used to lock resources. This works in-memory and also in a distributed fashion with REDIS.
-
-Ensure to provide proper locking options when using, although in-memory ignores those. 
-
-Example:
-
-```shell
-# invoked from an endpoint
-context := c.Request.Context()
-
-var err error
-var lock appLock
-
-if lock, err = h.lockService.lockWithOptions(context, "TEST-LOCK", withAppLockOptionExpiry(5*time.Minute), withAppLockOptionInfiniteRetries(), withAppLockOptionRetryDelay(5*time.Second)); err != nil {
-    _ = c.AbortWithError(errToHttpStatus(err), err)
-    return
-}
-# defer to avoid leakage
-defer func(lock appLock) {
-    _ = lock.unlock(context)
-}(lock)
-
-# simulate long running task
-time.Sleep(20 * time.Second)
-```
+    * Repositories, handlers and services should always properly return `error` including any `init`-like function (
+      best
+      to avoid them and call in `newXXX`). **Do not abort with `Fatalf` or similar**
+    * `log.Fatalf` or `zap.L().Fatal` is allowed in `environment.go` or `app.go`
+* Look into the `_doc/` folder for [OpenAPI specification](./_doc/api.yaml) and a Postman Collection.
+* Consider reading [Effective Go](https://go.dev/doc/effective_go)
+* Consider reading [100 Go Mistakes and How to Avoid Them](https://100go.co/)
 
 ### Getting started
 
+Ensure to set the following environment variables for proper debug logs during development
+
+```shell
+DEVELOPMENT=true
+LOGGING_ENCODING=console
+LOGGING_LEVEL=debug
+```
+
 1. Run `make clean dependencies` to fetch dependencies
 2. Start `git.myservermanager.com/varakh/upda/cmd/server` (or `cli`) as Go application and ensure to have _required_
    environment variables set
@@ -100,6 +75,34 @@ path.
 For any `go` command you run, ensure that your `PATH` has the `gcc` binary and that you add `CGO_ENABLED=1` as
 environment.
 
+### Using the `lockService` correctly
+
+The `lockService` can be used to lock resources. This works in-memory and also in a distributed fashion with REDIS.
+
+Ensure to provide proper locking options when using, although in-memory ignores those.
+
+Example:
+
+```shell
+# invoked from an endpoint
+context := c.Request.Context()
+
+var err error
+var lock appLock
+
+if lock, err = h.lockService.lockWithOptions(context, "TEST-LOCK", withAppLockOptionExpiry(5*time.Minute), withAppLockOptionInfiniteRetries(), withAppLockOptionRetryDelay(5*time.Second)); err != nil {
+    _ = c.AbortWithError(errToHttpStatus(err), err)
+    return
+}
+# defer to avoid leakage
+defer func(lock appLock) {
+    _ = lock.unlock(context)
+}(lock)
+
+# simulate long running task
+time.Sleep(20 * time.Second)
+```
+
 ### Release
 
 Releases are handled by the SCM platform and pipeline. Creating a **new git tag**, creates a new release in the SCM

go.mod

@@ -20,6 +20,7 @@ require (
 	github.com/redis/go-redis/v9 v9.5.2
 	github.com/stretchr/testify v1.9.0
 	github.com/urfave/cli/v2 v2.27.2
+	go.uber.org/automaxprocs v1.5.3
 	go.uber.org/zap v1.27.0
 	gorm.io/driver/postgres v1.5.7
 	gorm.io/driver/sqlite v1.5.5

go.sum

@@ -191,6 +191,8 @@ github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZb
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/power-devops/perfstat v0.0.0-20210106213030-5aafc221ea8c h1:ncq/mPwQF4JjgDlrVEn3C11VoGHZN7m8qihwgMEtzYw=
 github.com/power-devops/perfstat v0.0.0-20210106213030-5aafc221ea8c/go.mod h1:OmDBASR4679mdNQnz2pUhc2G8CO2JrUAVFDRBDP/hJE=
+github.com/prashantv/gostub v1.1.0 h1:BTyx3RfQjRHnUWaGF9oQos79AlQ5k8WNktv7VGvVH4g=
+github.com/prashantv/gostub v1.1.0/go.mod h1:A5zLQHz7ieHGG7is6LLXLz7I8+3LZzsrV0P1IAHhP5U=
 github.com/prometheus/client_golang v1.18.0 h1:HzFfmkOzH5Q8L8G+kSJKUx5dtG87sewO+FoDDqP5Tbk=
 github.com/prometheus/client_golang v1.18.0/go.mod h1:T+GXkCk5wSJyOqMIzVgvvjFDlkOQntgjkJWKrN5txjA=
 github.com/prometheus/client_model v0.5.0 h1:VQw1hfvPvk3Uv6Qf29VrPF32JB6rtbgI6cYPYQjL0Qw=
@@ -250,6 +252,8 @@ github.com/yuin/goldmark v1.4.13/go.mod h1:6yULJ656Px+3vBD8DxQVa3kxgyrAnzto9xy5t
 github.com/yusufpapurcu/wmi v1.2.3 h1:E1ctvB7uKFMOJw3fdOW32DwGE9I7t++CRUEMKvFoFiw=
 github.com/yusufpapurcu/wmi v1.2.3/go.mod h1:SBZ9tNy3G9/m5Oi98Zks0QjeHVDvuK0qfxQmPyzfmi0=
 go.uber.org/atomic v1.7.0/go.mod h1:fEN4uk6kAWBTFdckzkM89CLk9XfWZrxpCo0nPH17wJc=
+go.uber.org/automaxprocs v1.5.3 h1:kWazyxZUrS3Gs4qUpbwo5kEIMGe/DAvi5Z4tl2NW4j8=
+go.uber.org/automaxprocs v1.5.3/go.mod h1:eRbA25aqJrxAbsLO0xy5jVwPt7FQnRgjW+efnwa1WM0=
 go.uber.org/goleak v1.1.11/go.mod h1:cwTWslyiVhfpKIDGSZEM2HlOvcqm+tG4zioyIeLoqMQ=
 go.uber.org/goleak v1.3.0 h1:2K3zAYmnTNqV73imy9J1T3WC+gmCePx2hEGkimedGto=
 go.uber.org/goleak v1.3.0/go.mod h1:CoHD4mav9JJNrW/WLlf7HGZPjdw8EucARQHekz1X6bE=

server/api_handler_action.go

@@ -29,7 +29,7 @@ func (h *actionHandler) paginate(c *gin.Context) {
 	}
 
 	var data []*api.ActionResponse
-	data = make([]*api.ActionResponse, 0)
+	data = make([]*api.ActionResponse, 0, len(actions))
 
 	for _, e := range actions {
 		data = append(data, &api.ActionResponse{

server/api_handler_action_invocation.go

@@ -56,7 +56,7 @@ func (h *actionInvocationHandler) paginate(c *gin.Context) {
 	}
 
 	var data []*api.ActionInvocationResponse
-	data = make([]*api.ActionInvocationResponse, 0)
+	data = make([]*api.ActionInvocationResponse, 0, len(actionInvocations))
 
 	for _, e := range actionInvocations {
 		data = append(data, &api.ActionInvocationResponse{

server/api_handler_event.go

@@ -29,7 +29,7 @@ func (h *eventHandler) window(c *gin.Context) {
 	}
 
 	var data []*api.EventResponse
-	data = make([]*api.EventResponse, 0)
+	data = make([]*api.EventResponse, 0, len(events))
 
 	for _, e := range events {
 		data = append(data, &api.EventResponse{

server/api_handler_secret.go

@@ -24,7 +24,7 @@ func (h *secretHandler) getAll(c *gin.Context) {
 	}
 
 	var data []*api.SecretResponse
-	data = make([]*api.SecretResponse, 0)
+	data = make([]*api.SecretResponse, 0, len(secrets))
 
 	for _, e := range secrets {
 		data = append(data, &api.SecretResponse{

server/api_handler_update.go

@@ -28,7 +28,7 @@ func (h *updateHandler) paginate(c *gin.Context) {
 
 	s, stateQueryContainsAtLeastOne := c.GetQueryArray("state")
 
-	var states []api.UpdateState
+	states := make([]api.UpdateState, 0)
 	if stateQueryContainsAtLeastOne {
 		for _, state := range s {
 			states = append(states, api.UpdateState(state))

server/api_handler_webhook.go

@@ -29,7 +29,7 @@ func (h *webhookHandler) paginate(c *gin.Context) {
 	}
 
 	var data []*api.WebhookResponse
-	data = make([]*api.WebhookResponse, 0)
+	data = make([]*api.WebhookResponse, 0, len(webhooks))
 
 	for _, e := range webhooks {
 		data = append(data, &api.WebhookResponse{

server/app.go

@@ -8,6 +8,7 @@ import (
 	"github.com/gin-contrib/cors"
 	ginzap "github.com/gin-contrib/zap"
 	"github.com/gin-gonic/gin"
+	_ "go.uber.org/automaxprocs"
 	"go.uber.org/zap"
 	"net/http"
 	"os"
@@ -30,16 +31,20 @@ func Start() {
 		gin.SetMode(gin.ReleaseMode)
 	}
 
+	// app init (router, services, handlers)
 	router := gin.New()
 	router.Use(ginzap.Ginzap(zap.L(), time.RFC3339, false))
 	router.Use(ginzap.RecoveryWithZap(zap.L(), true))
 
-	// metrics
-	prometheusService := newPrometheusService(router, env.prometheusConfig)
+	var err error
+
+	ps := newPrometheusService(router, env.prometheusConfig)
 
 	if env.prometheusConfig.enabled {
-		prometheusService.init()
-		router.Use(prometheusService.prometheus.Instrument())
+		if err = ps.init(); err != nil {
+			zap.L().Sugar().Fatalf("Prometheus service init failed: %s", err.Error())
+		}
+		router.Use(ps.prometheus.Instrument())
 	}
 
 	updateRepo := newUpdateDbRepo(env.db)
@@ -49,43 +54,51 @@ func Start() {
 	actionRepo := newActionDbRepo(env.db)
 	actionInvocationRepo := newActionInvocationDbRepo(env.db)
 
-	var lockService lockService
+	var ls lockService
 
 	if env.lockConfig.redisEnabled {
-		var err error
-		lockService, err = newLockRedisService(env.lockConfig)
+		var e error
+		ls, e = newLockRedisService(env.lockConfig)
 
 		if err != nil {
-			zap.L().Fatal("Failed to create lock service", zap.Error(err))
+			zap.L().Fatal("Failed to create lock service", zap.Error(e))
 		}
 	} else {
-		lockService = newLockMemService()
+		ls = newLockMemService()
 	}
 
-	eventService := newEventService(eventRepo)
-	updateService := newUpdateService(updateRepo, eventService)
-	webhookService := newWebhookService(webhookRepo, env.webhookConfig)
-	webhookInvocationService := newWebhookInvocationService(webhookService, updateService, env.webhookConfig)
+	es := newEventService(eventRepo)
+	us := newUpdateService(updateRepo, es)
+	ws := newWebhookService(webhookRepo, env.webhookConfig)
+	wis := newWebhookInvocationService(ws, us, env.webhookConfig)
 
-	secretService := newSecretService(secretRepo)
-	actionService := newActionService(actionRepo, eventService)
-	actionInvocationService := newActionInvocationService(actionInvocationRepo, actionService, eventService, secretService)
+	ss := newSecretService(secretRepo)
+	as := newActionService(actionRepo, es)
+	ais := newActionInvocationService(actionInvocationRepo, as, es, ss)
 
-	taskService := newTaskService(updateService, eventService, webhookService, actionService, actionInvocationService, lockService, prometheusService, env.appConfig, env.taskConfig, env.lockConfig, env.prometheusConfig)
-	taskService.init()
-	taskService.start()
+	var ts *taskService
 
-	updateHandler := newUpdateHandler(updateService, env.appConfig)
-	webhookHandler := newWebhookHandler(webhookService)
-	webhookInvocationHandler := newWebhookInvocationHandler(webhookInvocationService, webhookService)
-	eventHandler := newEventHandler(eventService)
-	secretHandler := newSecretHandler(secretService)
-	actionHandler := newActionHandler(actionService)
-	actionInvocationHandler := newActionInvocationHandler(actionService, actionInvocationService)
+	if ts, err = newTaskService(us, es, ws, as, ais, ls, ps, env.appConfig, env.taskConfig, env.lockConfig, env.prometheusConfig); err != nil {
+		zap.L().Sugar().Fatalf("Task service creation failed: %v", err)
+	}
 
-	infoHandler := newInfoHandler(env.appConfig)
-	healthHandler := newHealthHandler()
-	authHandler := newAuthHandler()
+	if err = ts.init(); err != nil {
+		zap.L().Sugar().Fatalf("Task service initialization failed: %v", err)
+	}
+
+	ts.start()
+
+	uh := newUpdateHandler(us, env.appConfig)
+	wh := newWebhookHandler(ws)
+	wih := newWebhookInvocationHandler(wis, ws)
+	eh := newEventHandler(es)
+	sh := newSecretHandler(ss)
+	ah := newActionHandler(as)
+	aih := newActionInvocationHandler(as, ais)
+
+	ih := newInfoHandler(env.appConfig)
+	hh := newHealthHandler()
+	authH := newAuthHandler()
 
 	router.Use(middlewareAppName())
 	router.Use(middlewareAppVersion())
@@ -101,10 +114,10 @@ func Start() {
 	}))
 
 	apiPublicGroup := router.Group("/api/v1")
-	apiPublicGroup.GET("/health", healthHandler.show)
-	apiPublicGroup.GET("/info", infoHandler.show)
+	apiPublicGroup.GET("/health", hh.show)
+	apiPublicGroup.GET("/info", ih.show)
 
-	apiPublicGroup.POST("/webhooks/:id", webhookInvocationHandler.execute)
+	apiPublicGroup.POST("/webhooks/:id", wih.execute)
 
 	var authMethodHandler gin.HandlerFunc
 
@@ -120,48 +133,47 @@ func Start() {
 
 	apiAuthGroup := router.Group("/api/v1", authMethodHandler)
 
-	apiAuthGroup.GET("/login", authHandler.login)
+	apiAuthGroup.GET("/login", authH.login)
 
-	apiAuthGroup.GET("/updates", updateHandler.paginate)
-	apiAuthGroup.GET("/updates/:id", updateHandler.get)
-	apiAuthGroup.PATCH("/updates/:id/state", updateHandler.updateState)
-	apiAuthGroup.DELETE("/updates/:id", updateHandler.delete)
+	apiAuthGroup.GET("/updates", uh.paginate)
+	apiAuthGroup.GET("/updates/:id", uh.get)
+	apiAuthGroup.PATCH("/updates/:id/state", uh.updateState)
+	apiAuthGroup.DELETE("/updates/:id", uh.delete)
 
-	apiAuthGroup.GET("/webhooks", webhookHandler.paginate)
-	apiAuthGroup.POST("/webhooks", webhookHandler.create)
-	apiAuthGroup.GET("/webhooks/:id", webhookHandler.get)
-	apiAuthGroup.PATCH("/webhooks/:id/label", webhookHandler.updateLabel)
-	apiAuthGroup.PATCH("/webhooks/:id/ignore-host", webhookHandler.updateIgnoreHost)
-	apiAuthGroup.DELETE("/webhooks/:id", webhookHandler.delete)
+	apiAuthGroup.GET("/webhooks", wh.paginate)
+	apiAuthGroup.POST("/webhooks", wh.create)
+	apiAuthGroup.GET("/webhooks/:id", wh.get)
+	apiAuthGroup.PATCH("/webhooks/:id/label", wh.updateLabel)
+	apiAuthGroup.PATCH("/webhooks/:id/ignore-host", wh.updateIgnoreHost)
+	apiAuthGroup.DELETE("/webhooks/:id", wh.delete)
 
-	apiAuthGroup.GET("/events", eventHandler.window)
-	apiAuthGroup.GET("/events/:id", eventHandler.get)
-	apiAuthGroup.DELETE("/events/:id", eventHandler.delete)
+	apiAuthGroup.GET("/events", eh.window)
+	apiAuthGroup.GET("/events/:id", eh.get)
+	apiAuthGroup.DELETE("/events/:id", eh.delete)
 
-	apiAuthGroup.GET("/secrets", secretHandler.getAll)
-	apiAuthGroup.GET("/secrets/:id", secretHandler.get)
-	apiAuthGroup.POST("/secrets", secretHandler.create)
-	apiAuthGroup.PATCH("/secrets/:id/value", secretHandler.updateValue)
-	apiAuthGroup.DELETE("/secrets/:id", secretHandler.delete)
+	apiAuthGroup.GET("/secrets", sh.getAll)
+	apiAuthGroup.GET("/secrets/:id", sh.get)
+	apiAuthGroup.POST("/secrets", sh.create)
+	apiAuthGroup.PATCH("/secrets/:id/value", sh.updateValue)
+	apiAuthGroup.DELETE("/secrets/:id", sh.delete)
 
-	apiAuthGroup.GET("/actions", actionHandler.paginate)
-	apiAuthGroup.POST("/actions", actionHandler.create)
-	apiAuthGroup.GET("/actions/:id", actionHandler.get)
-	apiAuthGroup.PATCH("/actions/:id/label", actionHandler.updateLabel)
-	apiAuthGroup.PATCH("/actions/:id/match-event", actionHandler.updateMatchEvent)
-	apiAuthGroup.PATCH("/actions/:id/match-host", actionHandler.updateMatchHost)
-	apiAuthGroup.PATCH("/actions/:id/match-application", actionHandler.updateMatchApplication)
-	apiAuthGroup.PATCH("/actions/:id/match-provider", actionHandler.updateMatchProvider)
-	apiAuthGroup.PATCH("/actions/:id/payload", actionHandler.updatePayload)
-	apiAuthGroup.PATCH("/actions/:id/enabled", actionHandler.updateEnabled)
-	apiAuthGroup.DELETE("/actions/:id", actionHandler.delete)
-	apiAuthGroup.POST("/actions/:id/test", actionInvocationHandler.test)
+	apiAuthGroup.GET("/actions", ah.paginate)
+	apiAuthGroup.POST("/actions", ah.create)
+	apiAuthGroup.GET("/actions/:id", ah.get)
+	apiAuthGroup.PATCH("/actions/:id/label", ah.updateLabel)
+	apiAuthGroup.PATCH("/actions/:id/match-event", ah.updateMatchEvent)
+	apiAuthGroup.PATCH("/actions/:id/match-host", ah.updateMatchHost)
+	apiAuthGroup.PATCH("/actions/:id/match-application", ah.updateMatchApplication)
+	apiAuthGroup.PATCH("/actions/:id/match-provider", ah.updateMatchProvider)
+	apiAuthGroup.PATCH("/actions/:id/payload", ah.updatePayload)
+	apiAuthGroup.PATCH("/actions/:id/enabled", ah.updateEnabled)
+	apiAuthGroup.DELETE("/actions/:id", ah.delete)
+	apiAuthGroup.POST("/actions/:id/test", aih.test)
 
-	apiAuthGroup.GET("/action-invocations", actionInvocationHandler.paginate)
-	apiAuthGroup.GET("/action-invocations/:id", actionInvocationHandler.get)
-	apiAuthGroup.DELETE("/action-invocations/:id", actionInvocationHandler.delete)
+	apiAuthGroup.GET("/action-invocations", aih.paginate)
+	apiAuthGroup.GET("/action-invocations/:id", aih.get)
+	apiAuthGroup.DELETE("/action-invocations/:id", aih.delete)
 
-	// start server
 	serverAddress := fmt.Sprintf("%s:%d", env.serverConfig.listen, env.serverConfig.port)
 	srv := &http.Server{
 		Addr:    serverAddress,
@@ -169,16 +181,16 @@ func Start() {
 	}
 
 	go func() {
-		var err error
+		var e error
 
 		if env.serverConfig.tlsEnabled {
-			err = srv.ListenAndServeTLS(env.serverConfig.tlsCertPath, env.serverConfig.tlsKeyPath)
+			e = srv.ListenAndServeTLS(env.serverConfig.tlsCertPath, env.serverConfig.tlsKeyPath)
 		} else {
-			err = srv.ListenAndServe()
+			e = srv.ListenAndServe()
 		}
 
-		if err != nil && !errors.Is(err, http.ErrServerClosed) {
-			zap.L().Sugar().Fatalf("Application cannot be started: %v", err)
+		if e != nil && !errors.Is(e, http.ErrServerClosed) {
+			zap.L().Sugar().Fatalf("Application cannot be started: %v", e)
 		}
 	}()
 
@@ -192,11 +204,11 @@ func Start() {
 	signal.Notify(quit, syscall.SIGINT, syscall.SIGTERM)
 	<-quit
 	zap.L().Info("Shutting down...")
-	taskService.stop()
+	ts.stop()
 
 	ctx, cancel := context.WithTimeout(context.Background(), env.serverConfig.timeout)
 	defer cancel()
-	if err := srv.Shutdown(ctx); err != nil {
+	if err = srv.Shutdown(ctx); err != nil {
 		zap.L().Sugar().Fatalf("Shutdown failed, exited directly: %v", err)
 	}
 	// catching ctx.Done() for configured timeout

server/datatype_json_map.go

@@ -14,7 +14,7 @@ import (
 	"gorm.io/gorm/clause"
 )
 
-// JSONMap defined JSON data type, need to implements driver.Valuer, sql.Scanner interface
+// JSONMap defined JSON data type, need to implement driver.Valuer, sql.Scanner interface
 type JSONMap map[string]interface {
 }
 
@@ -27,7 +27,7 @@ func (m JSONMap) Value() (driver.Value, error) {
 	return string(ba), err
 }
 
-// Scan scan value into Jsonb, implements sql.Scanner interface
+// Scan value into JSONB, implements sql.Scanner interface
 func (m *JSONMap) Scan(val interface{}) error {
 	if val == nil {
 		*m = make(JSONMap)

server/environment.go

@@ -165,7 +165,9 @@ func bootstrapEnvironment() *Environment {
 	}
 
 	zapLogger := zap.Must(zapConfig.Build())
-	defer zapLogger.Sync()
+	defer func(zapLogger *zap.Logger) {
+		_ = zapLogger.Sync()
+	}(zapLogger)
 	zap.ReplaceGlobals(zapLogger)
 
 	// assign defaults from given environment variables and validate
@@ -323,7 +325,9 @@ func bootstrapEnvironment() *Environment {
 	gormConfig := &gorm.Config{Logger: logger.Default.LogMode(logger.Silent)}
 	if isDebug && isDevelopment {
 		gormZapLogger := zap.Must(zapConfig.Build())
-		defer gormZapLogger.Sync()
+		defer func(gormZapLogger *zap.Logger) {
+			_ = gormZapLogger.Sync()
+		}(gormZapLogger)
 		gormLogger := zapgorm2.New(gormZapLogger)
 		gormConfig = &gorm.Config{Logger: gormLogger}
 	}

server/repository_action_invocation.go

@@ -225,8 +225,8 @@ func (r *actionInvocationDbRepo) deleteByUpdatedAtBeforeAndStates(time time.Time
 }
 
 func translateActionInvocationState(state ...api.ActionInvocationState) []string {
-	states := make([]string, 0)
-	if len(state) > 0 {
+	states := make([]string, 0, len(state))
+	if len(states) > 0 {
 		for _, s := range state {
 			states = append(states, s.Value())
 		}

server/repository_event.go

@@ -125,7 +125,7 @@ func (r *eventDbRepo) deleteByUpdatedAtBeforeAndStates(time time.Time, state ...
 		return 0, errorValidationNotEmpty
 	}
 
-	states := make([]string, 0)
+	states := make([]string, 0, len(state))
 	for _, i := range state {
 		states = append(states, i.Value())
 	}

server/repository_update.go

@@ -199,7 +199,7 @@ func (r *updateDbRepo) deleteByUpdatedAtBeforeAndStates(time time.Time, state ..
 		return 0, errorValidationNotEmpty
 	}
 
-	states := make([]string, 0)
+	states := make([]string, 0, len(state))
 	for _, i := range state {
 		states = append(states, i.Value())
 	}
@@ -231,8 +231,8 @@ func (r *updateDbRepo) paginate(page int, pageSize int, orderBy string, order st
 		order = "desc"
 	}
 
-	states := make([]string, 0)
-	if len(state) > 0 {
+	states := make([]string, 0, len(state))
+	if len(states) > 0 {
 		for _, s := range state {
 			states = append(states, s.Value())
 		}
@@ -248,8 +248,8 @@ func (r *updateDbRepo) paginate(page int, pageSize int, orderBy string, order st
 func (r *updateDbRepo) count(searchTerm string, searchIn string, state ...api.UpdateState) (int64, error) {
 	var c int64
 
-	states := make([]string, 0)
-	if len(state) > 0 {
+	states := make([]string, 0, len(state))
+	if len(states) > 0 {
 		for _, s := range state {
 			states = append(states, s.Value())
 		}

server/service_action_invocation.go

@@ -65,7 +65,8 @@ func (s *actionInvocationService) enqueueFromEvent(event *Event, actions []*Acti
 		return err
 	}
 
-	var filteredActions []*Action
+	filteredActions := make([]*Action, 0)
+
 	for _, action := range actions {
 		matchesEvent := action.MatchEvent == nil || *action.MatchEvent == event.Name
 		matchesHost := action.MatchHost == nil || *action.MatchHost == eventPayload.Host

server/service_lock_mem.go

@@ -17,7 +17,7 @@ var (
 )
 
 func newLockMemService() lockService {
-	zap.L().Info("Initialized in-memory locking service")
+	zap.L().Info("Initializing in-memory locking service")
 	return &lockMemService{registry: util.NewInMemoryLockRegistry()}
 }
 

server/service_lock_redis.go

@@ -20,19 +20,19 @@ var (
 )
 
 func newLockRedisService(lc *lockConfig) (lockService, error) {
-	zap.L().Info("Initialized REDIS locking service")
+	zap.L().Info("Initializing REDIS locking service")
 
 	var err error
 	var redisOptions *redis.Options
 	redisOptions, err = redis.ParseURL(lc.redisUrl)
 
 	if err != nil {
-		zap.L().Sugar().Fatalf("Cannot parse REDIS URL '%s' to set up locking. Reason: %s", lc.redisUrl, err.Error())
+		return nil, fmt.Errorf("lock service: cannot parse REDIS URL '%s' to set up locking: %s", lc.redisUrl, err)
 	}
 
 	c := redis.NewClient(redisOptions)
 	if err = c.Ping(context.Background()).Err(); err != nil {
-		return nil, newServiceError(General, fmt.Errorf("lock service: failed to connect to REDIS. Reason: %w", err))
+		return nil, fmt.Errorf("lock service: failed to connect to REDIS: %w", err)
 	}
 
 	pool := redsyncgoredis.NewPool(c)

server/service_prometheus.go

@@ -1,9 +1,9 @@
 package server
 
 import (
+    "fmt"
     "github.com/Depado/ginprom"
     "github.com/gin-gonic/gin"
-	"go.uber.org/zap"
 )
 
 type prometheusService struct {
@@ -42,9 +42,9 @@ func newPrometheusService(r *gin.Engine, c *prometheusConfig) *prometheusService
 	}
 }
 
-func (s *prometheusService) init() {
+func (s *prometheusService) init() error {
 	if !s.config.enabled {
-		return
+		return nil
 	}
 
 	var err error
@@ -59,8 +59,10 @@ func (s *prometheusService) init() {
 	err = s.registerGaugeNoLabels(metricActions, metricActionsHelp)
 
 	if err != nil {
-		zap.L().Sugar().Fatalf("Cannot initialize service. Reason: %v", err)
+		return newServiceError(General, fmt.Errorf("cannot initialize service: %w", err))
 	}
+
+	return nil
 }
 
 func (s *prometheusService) registerGaugeNoLabels(name string, help string) error {

server/service_task.go

@@ -1,6 +1,7 @@
 package server
 
 import (
+	"fmt"
 	"git.myservermanager.com/varakh/upda/api"
 	redislock "github.com/go-co-op/gocron-redis-lock/v2"
 	"github.com/go-co-op/gocron/v2"
@@ -38,11 +39,11 @@ var (
 	initialTasksStartDelay = time.Now().Add(10 * time.Second)
 )
 
-func newTaskService(u *updateService, e *eventService, w *webhookService, a *actionService, ai *actionInvocationService, l lockService, p *prometheusService, ac *appConfig, tc *taskConfig, lc *lockConfig, pc *prometheusConfig) *taskService {
-	location, err := time.LoadLocation(ac.timeZone)
-
-	if err != nil {
-		zap.L().Sugar().Fatalf("Could not initialize correct timezone for scheduler. Reason: %s", err.Error())
+func newTaskService(u *updateService, e *eventService, w *webhookService, a *actionService, ai *actionInvocationService, l lockService, p *prometheusService, ac *appConfig, tc *taskConfig, lc *lockConfig, pc *prometheusConfig) (*taskService, error) {
+	var err error
+	var location *time.Location
+	if location, err = time.LoadLocation(ac.timeZone); err != nil {
+		return nil, fmt.Errorf("could not initialize correct timezone for scheduler: %s", err)
 	}
 
 	// global job options
@@ -64,13 +65,13 @@ func newTaskService(u *updateService, e *eventService, w *webhookService, a *act
 		redisOptions, err = redis.ParseURL(lc.redisUrl)
 
 		if err != nil {
-			zap.L().Sugar().Fatalf("Cannot parse REDIS URL '%s' to set up locking. Reason: %s", lc.redisUrl, err.Error())
+			return nil, fmt.Errorf("cannot parse REDIS URL '%s' to set up locking for scheduler: %s", lc.redisUrl, err)
 		}
 		redisClient := redis.NewClient(redisOptions)
 
 		var locker gocron.Locker
 		if locker, err = redislock.NewRedisLocker(redisClient, redislock.WithTries(1), redislock.WithExpiry(30*time.Second), redislock.WithRetryDelay(5*time.Second)); err != nil {
-			zap.L().Sugar().Fatalf("Cannot set up REDIS locker. Reason: %s", err.Error())
+			return nil, fmt.Errorf("cannot set up REDIS locker for scheduler: %s", err)
 		}
 
 		schedulerOptions = append(schedulerOptions, gocron.WithDistributedLocker(locker))
@@ -91,16 +92,30 @@ func newTaskService(u *updateService, e *eventService, w *webhookService, a *act
 		lockConfig:              lc,
 		prometheusConfig:        pc,
 		scheduler:               scheduler,
-	}
+	}, nil
 }
 
-func (s *taskService) init() {
-	s.configureCleanupStaleUpdatesTask()
-	s.configureCleanupStaleEventsTask()
-	s.configureActionsEnqueueTask()
-	s.configureActionsInvokeTask()
-	s.configureCleanupStaleActionsTask()
-	s.configurePrometheusRefreshTask()
+func (s *taskService) init() error {
+	if err := s.configureCleanupStaleUpdatesTask(); err != nil {
+		return err
+	}
+	if err := s.configureCleanupStaleEventsTask(); err != nil {
+		return err
+	}
+	if err := s.configureActionsEnqueueTask(); err != nil {
+		return err
+	}
+	if err := s.configureActionsInvokeTask(); err != nil {
+		return err
+	}
+	if err := s.configureCleanupStaleActionsTask(); err != nil {
+		return err
+	}
+	if err := s.configurePrometheusRefreshTask(); err != nil {
+		return err
+	}
+
+	return nil
 }
 
 func (s *taskService) stop() {
@@ -119,9 +134,9 @@ func (s *taskService) start() {
 	zap.L().Sugar().Infof("Started %d periodic tasks", len(s.scheduler.Jobs()))
 }
 
-func (s *taskService) configureCleanupStaleUpdatesTask() {
+func (s *taskService) configureCleanupStaleUpdatesTask() error {
 	if !s.taskConfig.updateCleanStaleEnabled {
-		return
+		return nil
 	}
 
 	runnable := func() {
@@ -145,13 +160,15 @@ func (s *taskService) configureCleanupStaleUpdatesTask() {
 
 	scheduledJob := gocron.DurationJob(s.taskConfig.updateCleanStaleInterval)
 	if _, err := s.scheduler.NewJob(scheduledJob, gocron.NewTask(runnable), gocron.WithName(jobUpdatesCleanStale)); err != nil {
-		zap.L().Sugar().Fatalf("Could not create task for cleaning stale updates. Reason: %s", err.Error())
-	}
+		return fmt.Errorf("could not create task for cleaning stale updates: %w", err)
 	}
 
-func (s *taskService) configureCleanupStaleEventsTask() {
+	return nil
+}
+
+func (s *taskService) configureCleanupStaleEventsTask() error {
 	if !s.taskConfig.eventCleanStaleEnabled {
-		return
+		return nil
 	}
 
 	runnable := func() {
@@ -175,13 +192,15 @@ func (s *taskService) configureCleanupStaleEventsTask() {
 
 	scheduledJob := gocron.DurationJob(s.taskConfig.eventCleanStaleInterval)
 	if _, err := s.scheduler.NewJob(scheduledJob, gocron.NewTask(runnable), gocron.WithName(jobEventsCleanStale)); err != nil {
-		zap.L().Sugar().Fatalf("Could not create task for cleaning stale events. Reason: %s", err.Error())
-	}
+		return fmt.Errorf("could not create task for cleaning stale events: %w", err)
 	}
 
-func (s *taskService) configureActionsEnqueueTask() {
+	return nil
+}
+
+func (s *taskService) configureActionsEnqueueTask() error {
 	if !s.taskConfig.actionsEnqueueEnabled {
-		return
+		return nil
 	}
 
 	runnable := func() {
@@ -192,13 +211,15 @@ func (s *taskService) configureActionsEnqueueTask() {
 
 	scheduledJob := gocron.DurationJob(s.taskConfig.actionsEnqueueInterval)
 	if _, err := s.scheduler.NewJob(scheduledJob, gocron.NewTask(runnable), gocron.WithName(jobActionsEnqueue)); err != nil {
-		zap.L().Sugar().Fatalf("Could not create task for enqueueing actions. Reason: %s", err.Error())
-	}
+		return fmt.Errorf("could not create task for enqueueing actions: %w", err)
 	}
 
-func (s *taskService) configureActionsInvokeTask() {
+	return nil
+}
+
+func (s *taskService) configureActionsInvokeTask() error {
 	if !s.taskConfig.actionsInvokeEnabled {
-		return
+		return nil
 	}
 
 	runnable := func() {
@@ -209,13 +230,15 @@ func (s *taskService) configureActionsInvokeTask() {
 
 	scheduledJob := gocron.DurationJob(s.taskConfig.actionsInvokeInterval)
 	if _, err := s.scheduler.NewJob(scheduledJob, gocron.NewTask(runnable), gocron.WithName(jobActionsInvoke)); err != nil {
-		zap.L().Sugar().Fatalf("Could not create task for invoking actions. Reason: %s", err.Error())
-	}
+		return fmt.Errorf("could not create task for invoking actions: %w", err)
 	}
 
-func (s *taskService) configureCleanupStaleActionsTask() {
+	return nil
+}
+
+func (s *taskService) configureCleanupStaleActionsTask() error {
 	if !s.taskConfig.actionsCleanStaleEnabled {
-		return
+		return nil
 	}
 
 	runnable := func() {
@@ -246,13 +269,15 @@ func (s *taskService) configureCleanupStaleActionsTask() {
 
 	scheduledJob := gocron.DurationJob(s.taskConfig.actionsCleanStaleInterval)
 	if _, err := s.scheduler.NewJob(scheduledJob, gocron.NewTask(runnable), gocron.WithName(jobActionsCleanStale)); err != nil {
-		zap.L().Sugar().Fatalf("Could not create task for cleaning stale actions. Reason: %s", err.Error())
-	}
+		return fmt.Errorf("could not create task for cleaning stale actions: %w", err)
 	}
 
-func (s *taskService) configurePrometheusRefreshTask() {
+	return nil
+}
+
+func (s *taskService) configurePrometheusRefreshTask() error {
 	if !s.prometheusConfig.enabled {
-		return
+		return nil
 	}
 
 	runnable := func() {
@@ -310,6 +335,8 @@ func (s *taskService) configurePrometheusRefreshTask() {
 
 	scheduledJob := gocron.DurationJob(s.taskConfig.prometheusRefreshInterval)
 	if _, err := s.scheduler.NewJob(scheduledJob, gocron.NewTask(runnable), gocron.WithName(jobPrometheusRefresh)); err != nil {
-		zap.L().Sugar().Fatalf("Could not create task for refreshing prometheus. Reason: %s", err.Error())
+		return fmt.Errorf("could not create task for refreshing prometheus: %w", err)
 	}
+
+	return nil
 }

util/file.go

@@ -23,7 +23,9 @@ func CreateFileWithParent(file string) error {
 	if _, err = os.Stat(file); errors.Is(err, os.ErrNotExist) {
 		var f *os.File
 		f, err = os.Create(file)
-		defer f.Close()
+		defer func(f *os.File) {
+			_ = f.Close()
+		}(f)
 		if err != nil {
 			return errors.New(fmt.Sprintf("cannot create file '%v': %v", file, fmt.Errorf("%w", err)))
 		}