🛠️ add golang ci lint and fix lint errors (#56)

* add golang ci lint

* fix golang-ci output

* update golang ci

* add golangci config file

* fix linting issue

.github/workflows/golang.yaml

@@ -0,0 +1,18 @@
+name: golangci-lint
+on:
+  push:
+    tags:
+      - v*
+    branches:
+      - master
+  pull_request:
+jobs:
+  golangci:
+    name: lint
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - name: golangci-lint
+        uses: golangci/golangci-lint-action@v2
+        with:
+          version: v1.29

.golangci.yaml

@@ -0,0 +1,51 @@
+linters-settings:
+  golint:
+    min-confidence: 0
+  goimports:
+    local-prefixes: github.com/clastix/capsule
+  dupl:
+    threshold: 100
+  goconst:
+    min-len: 2
+    min-occurrences: 2
+linters:
+  disable-all: true
+  enable:
+    - bodyclose
+    - deadcode
+    - depguard
+    - dogsled
+    - dupl
+    - errcheck
+    - goconst
+    - gocritic
+    - gofmt
+    - goimports
+    - golint
+    - goprintffuncname
+    - gosimple
+    - govet
+    - ineffassign
+    - misspell
+    - nolintlint
+    - rowserrcheck
+    - staticcheck
+    - structcheck
+    - stylecheck
+    - typecheck
+    - unconvert
+    - unparam
+    - unused
+    - varcheck
+    - whitespace
+
+issues:
+  exclude:
+    - Using the variable on range scope .* in function literal
+
+service:
+  golangci-lint-version: 1.33.x
+
+run:
+  skip-files:
+    - "zz_.*\\.go$"

cmd/api/admin_api/api.go → cmd/api/adminapi/api.go

@@ -1,4 +1,4 @@
-package admin_api
+package adminapi
 
 import (
 	"context"
@@ -11,11 +11,11 @@ import (
 	"kannon.gyozatech.dev/internal/domains"
 )
 
-type adminApiService struct {
+type adminAPIService struct {
 	dm domains.DomainManager
 }
 
-func (s *adminApiService) GetDomains(ctx context.Context, in *emptypb.Empty) (*pb.GetDomainsResponse, error) {
+func (s *adminAPIService) GetDomains(ctx context.Context, in *emptypb.Empty) (*pb.GetDomainsResponse, error) {
 	domains, err := s.dm.GetAllDomains()
 	if err != nil {
 		return nil, err
@@ -28,7 +28,7 @@ func (s *adminApiService) GetDomains(ctx context.Context, in *emptypb.Empty) (*p
 	return &res, nil
 }
 
-func (s *adminApiService) CreateDomain(ctx context.Context, in *pb.CreateDomainRequest) (*pb.Domain, error) {
+func (s *adminAPIService) CreateDomain(ctx context.Context, in *pb.CreateDomainRequest) (*pb.Domain, error) {
 	domain, err := s.dm.CreateDomain(in.Domain)
 	if err != nil {
 		return nil, err
@@ -37,7 +37,7 @@ func (s *adminApiService) CreateDomain(ctx context.Context, in *pb.CreateDomainR
 	return dbDomainToProtoDomain(domain), nil
 }
 
-func (s *adminApiService) RegenerateDomainKey(ctx context.Context, in *pb.RegenerateDomainKeyRequest) (*pb.Domain, error) {
+func (s *adminAPIService) RegenerateDomainKey(ctx context.Context, in *pb.RegenerateDomainKeyRequest) (*pb.Domain, error) {
 	return nil, nil
 }
 
@@ -47,7 +47,7 @@ func CreateAdminAPIService(db *sql.DB) (pb.ApiServer, error) {
 	if err != nil {
 		return nil, err
 	}
-	api := adminApiService{
+	api := adminAPIService{
 		dm: dm,
 	}
 

cmd/api/mail_api/mailer.go → cmd/api/mailapi/mailer.go

@@ -1,4 +1,4 @@
-package mail_api
+package mailapi
 
 import (
 	"context"
@@ -20,13 +20,13 @@ import (
 	"kannon.gyozatech.dev/internal/templates"
 )
 
-type mailApiService struct {
+type mailAPIService struct {
 	domains     domains.DomainManager
 	templates   templates.Manager
 	sendingPoll pool.SendingPoolManager
 }
 
-func (s mailApiService) SendHTML(ctx context.Context, in *pb.SendHTMLRequest) (*pb.SendResponse, error) {
+func (s mailAPIService) SendHTML(ctx context.Context, in *pb.SendHTMLRequest) (*pb.SendResponse, error) {
 	domain, ok := s.getCallDomainFromContext(ctx)
 	if !ok {
 		logrus.Errorf("invalid login\n")
@@ -59,7 +59,7 @@ func (s mailApiService) SendHTML(ctx context.Context, in *pb.SendHTMLRequest) (*
 	return &response, nil
 }
 
-func (s mailApiService) SendTemplate(ctx context.Context, in *pb.SendTemplateRequest) (*pb.SendResponse, error) {
+func (s mailAPIService) SendTemplate(ctx context.Context, in *pb.SendTemplateRequest) (*pb.SendResponse, error) {
 	domain, ok := s.getCallDomainFromContext(ctx)
 	if !ok {
 		logrus.Errorf("invalid login\n")
@@ -92,11 +92,11 @@ func (s mailApiService) SendTemplate(ctx context.Context, in *pb.SendTemplateReq
 	return &response, nil
 }
 
-func (s mailApiService) Close() error {
+func (s mailAPIService) Close() error {
 	return s.domains.Close()
 }
 
-func (s mailApiService) getCallDomainFromContext(ctx context.Context) (sqlc.Domain, bool) {
+func (s mailAPIService) getCallDomainFromContext(ctx context.Context) (sqlc.Domain, bool) {
 	m, ok := metadata.FromIncomingContext(ctx)
 	if !ok {
 		logrus.Debugf("Cannot find metatada\n")
@@ -138,10 +138,9 @@ func (s mailApiService) getCallDomainFromContext(ctx context.Context) (sqlc.Doma
 	}
 
 	return domain, true
-
 }
 
-func NewMailApiService(dbi *sql.DB) (pb.MailerServer, error) {
+func NewMailAPIService(dbi *sql.DB) (pb.MailerServer, error) {
 	domainsCli, err := domains.NewDomainManager(dbi)
 	if err != nil {
 		return nil, err
@@ -157,7 +156,7 @@ func NewMailApiService(dbi *sql.DB) (pb.MailerServer, error) {
 		return nil, err
 	}
 
-	return &mailApiService{
+	return &mailAPIService{
 		domains:     domainsCli,
 		sendingPoll: sendingPoolCli,
 		templates:   templates,

cmd/api/main.go

@@ -8,51 +8,51 @@ import (
 	"sync"
 
 	"github.com/joho/godotenv"
-	"github.com/sirupsen/logrus"
 	log "github.com/sirupsen/logrus"
 	"google.golang.org/grpc"
-	"kannon.gyozatech.dev/cmd/api/admin_api"
-	"kannon.gyozatech.dev/cmd/api/mail_api"
+	"kannon.gyozatech.dev/cmd/api/adminapi"
+	"kannon.gyozatech.dev/cmd/api/mailapi"
 	"kannon.gyozatech.dev/generated/pb"
 )
 
 func main() {
 	log.SetFormatter(&log.JSONFormatter{})
-	runGrpcServer()
+	if err := runGrpcServer(); err != nil {
+		panic(err.Error())
+	}
 }
 
 func runGrpcServer() error {
-	godotenv.Load()
+	_ = godotenv.Load()
 
 	dbi, err := sql.Open("postgres", os.Getenv("DB_CONN"))
 	if err != nil {
 		panic(err)
 	}
 	defer dbi.Close()
 
-	adminApiService, err := admin_api.CreateAdminAPIService(dbi)
+	adminAPIService, err := adminapi.CreateAdminAPIService(dbi)
 	if err != nil {
-		logrus.Fatalf("Cannot create Admin API service: %v\n", err)
-		return err
+		return fmt.Errorf("cannot create Admin API service: %w", err)
 	}
 
-	mailApiService, err := mail_api.NewMailApiService(dbi)
+	mailAPIService, err := mailapi.NewMailAPIService(dbi)
 	if err != nil {
-		logrus.Fatalf("Cannot create Mailer API service: %v\n", err)
+		return fmt.Errorf("cannot create Mailer API service: %w", err)
 	}
 
 	wg := sync.WaitGroup{}
 	wg.Add(2)
 
 	go func() {
-		err := startApiServer(50051, adminApiService)
+		err := startAPIServer(50051, adminAPIService)
 		if err != nil {
 			panic("Cannot run api server")
 		}
 	}()
 
 	go func() {
-		err := startMailerServer(50052, mailApiService)
+		err := startMailerServer(50052, mailAPIService)
 		if err != nil {
 			panic("Cannot run mailer server")
 		}
@@ -63,7 +63,7 @@ func runGrpcServer() error {
 	return nil
 }
 
-func startApiServer(port uint16, srv pb.ApiServer) error {
+func startAPIServer(port uint16, srv pb.ApiServer) error {
 	addr := fmt.Sprintf("0.0.0.0:%d", port)
 	lis, err := net.Listen("tcp", addr)
 	if err != nil {

cmd/dispatcher/dispatcher.go

@@ -26,7 +26,7 @@ type appConfig struct {
 }
 
 func main() {
-	godotenv.Load()
+	_ = godotenv.Load()
 
 	var config appConfig
 	err := envconfig.Process("app", &config)
@@ -121,7 +121,9 @@ func handleErrors(mgr *jsm.Manager) {
 		} else {
 			logrus.Printf("[🛑 bump] %v %v - %v", errMsg.Email, errMsg.MessageId, errMsg.Msg)
 		}
-		msg.Ack()
+		if err := msg.Ack(); err != nil {
+			logrus.Errorf("Cannot hack msg to nats: %v\n", err)
+		}
 	}
 }
 
@@ -142,6 +144,8 @@ func handleDelivereds(mgr *jsm.Manager) {
 		} else {
 			logrus.Printf("[🚀 delivered] %v %v", deliveredMsg.Email, deliveredMsg.MessageId)
 		}
-		msg.Ack()
+		if err := msg.Ack(); err != nil {
+			logrus.Errorf("Cannot hack msg to nats: %v\n", err)
+		}
 	}
 }

cmd/sender/sender.go

@@ -4,25 +4,23 @@ import (
 	"context"
 	"flag"
 
-	"github.com/golang/protobuf/proto"
-	"github.com/joho/godotenv"
 	"github.com/nats-io/jsm.go"
 	"github.com/nats-io/nats.go"
 	"github.com/sirupsen/logrus"
+	"google.golang.org/protobuf/proto"
 	"google.golang.org/protobuf/types/known/timestamppb"
 	"kannon.gyozatech.dev/generated/pb"
 	"kannon.gyozatech.dev/internal/smtp"
 )
 
 func main() {
-	godotenv.Load()
 	senderHost := flag.String("sender-host", "sender.kannon.io", "Sender hostname for SMTP presentation")
-	natsUrl := flag.String("nasts-url", "nats", "Nats url connection")
+	natsURL := flag.String("nasts-url", "nats", "Nats url connection")
 	maxSendingJobs := flag.Uint("max-sending-jobs", 100, "Max Parallel Job for sending")
 
 	flag.Parse()
 
-	nc, err := nats.Connect(*natsUrl, nats.UseOldRequestStyle())
+	nc, err := nats.Connect(*natsURL, nats.UseOldRequestStyle())
 	if err != nil {
 		logrus.Fatalf("Cannot connect to nats: %v\n", err)
 	}
@@ -55,7 +53,9 @@ func handleSend(sender smtp.Sender, con *jsm.Consumer, nc *nats.Conn, maxParalle
 			if err != nil {
 				logrus.Errorf("error in handling message: %v\n", err.Error())
 			}
-			msg.Ack()
+			if err := msg.Ack(); err != nil {
+				logrus.Errorf("cannot hack message: %v\n", err.Error())
+			}
 			<-ch
 		}()
 	}

generated/sqlc/db_test.go

@@ -57,7 +57,7 @@ func TestMain(m *testing.M) {
 
 	if err = pool.Retry(func() error {
 		var err error
-		db, err = initDb(resource.GetPort("5432/tcp"))
+		db, err = initDB(resource.GetPort("5432/tcp"))
 		if err != nil {
 			logrus.Warnf("connection error: %v", err)
 			return err
@@ -144,7 +144,7 @@ func TestTemplates(t *testing.T) {
 	assert.Nil(t, err)
 }
 
-func initDb(dbPort string) (*sql.DB, error) {
+func initDB(dbPort string) (*sql.DB, error) {
 	url := fmt.Sprintf("postgresql://test:test@localhost:%v/test", dbPort)
 	db, err := conn(url)
 	if err != nil {

internal/dkim/signer.go

@@ -42,6 +42,5 @@ func decodeKey(dkimPrivateKey string) (*rsa.PrivateKey, error) {
 	if err != nil {
 		return nil, err
 	}
-	rsak, err := x509.ParsePKCS1PrivateKey(dkimPrivateKeyInBytes)
-	return rsak, nil
+	return x509.ParsePKCS1PrivateKey(dkimPrivateKeyInBytes)
 }

internal/mailbuilder/mailbuilder.go

@@ -4,7 +4,10 @@ import (
 	"bytes"
 	"context"
 	"database/sql"
+	"time"
 
+	"github.com/sirupsen/logrus"
+	"gopkg.in/mail.v2"
 	"kannon.gyozatech.dev/generated/pb"
 	"kannon.gyozatech.dev/generated/sqlc"
 	"kannon.gyozatech.dev/internal/dkim"
@@ -60,8 +63,8 @@ func (m *mailBuilder) PerpareForSend(email sqlc.SendingPoolEmail) (pb.EmailToSen
 
 func prepareMessage(sender pool.Sender, subject string, to string, messageID string, html string, baseHeaders headers) ([]byte, error) {
 	emailMessageID := buildEmailMessageID(to, messageID)
-	headers := buildHeaders(subject, sender, to, messageID, emailMessageID, baseHeaders)
-	return renderMsg(html, sender.Email, to, headers)
+	h := buildHeaders(subject, sender, to, messageID, emailMessageID, baseHeaders)
+	return renderMsg(html, h)
 }
 
 func signMessage(domain string, dkimPrivateKey string, msg []byte) ([]byte, error) {
@@ -74,3 +77,22 @@ func signMessage(domain string, dkimPrivateKey string, msg []byte) ([]byte, erro
 
 	return dkim.SignMessage(signData, bytes.NewReader(msg))
 }
+
+// renderMsg render a MsgPayload to an SMTP message
+func renderMsg(html string, headers headers) ([]byte, error) {
+	msg := mail.NewMessage()
+
+	for key, value := range headers {
+		msg.SetHeader(key, value)
+	}
+	msg.SetDateHeader("Date", time.Now())
+	msg.SetBody("text/html", html)
+
+	var buff bytes.Buffer
+	if _, err := msg.WriteTo(&buff); err != nil {
+		logrus.Warnf("🤢 Error writing message: %v\n", err)
+		return nil, err
+	}
+
+	return buff.Bytes(), nil
+}