Reactor auth.File and instantiate authenticators in main.go

Author: metalmatze

auth/file.go

@@ -12,10 +12,10 @@ import (
 
 // Structs
 
-// FileAuthenticator contains file based authentication
+// File contains file based authentication
 // information including the in-memory map of username to
 // password mapping.
-type FileAuthenticator struct {
+type File struct {
 	Users []User
 }
 
@@ -28,20 +28,20 @@ type User struct {
 
 // Functions
 
-// NewFileAuthenticator takes in a file name and a separator,
+// NewFile takes in a file name and a separator,
 // reads in specified file and parses it line by line as
 // username - password elements separated by the separator.
 // At the end, the returned struct contains the information
 // and an in-memory map of username mapped to password.
-func NewFileAuthenticator(file string, sep string) (*FileAuthenticator, error) {
+func NewFile(file string, sep string) (*File, error) {
 
 	// Reserve space for the ordered users list in memory.
 	users := make([]User, 0, 50)
 
 	// Open file with authentication information.
 	handle, err := os.Open(file)
 	if err != nil {
-		return nil, fmt.Errorf("[auth.NewFileAuthenticator] Could not open supplied authentication file: %v", err)
+		return nil, fmt.Errorf("[auth.NewFile] Could not open supplied authentication file: %v", err)
 	}
 	defer handle.Close()
 
@@ -71,22 +71,22 @@ func NewFileAuthenticator(file string, sep string) (*FileAuthenticator, error) {
 
 	// If the scanner ended with an error, report it.
 	if err := scanner.Err(); err != nil {
-		return nil, fmt.Errorf("[auth.NewFileAuthenticator] Experienced error while scanning authentication file: %v", err)
+		return nil, fmt.Errorf("[auth.NewFile] Experienced error while scanning authentication file: %v", err)
 	}
 
 	// Sort users list to search it efficiently later on.
 	sort.Slice(users, func(i, j int) bool {
 		return users[i].Name < users[j].Name
 	})
 
-	return &FileAuthenticator{
+	return &File{
 		Users: users,
 	}, nil
 }
 
 // GetWorkerForUser returns the name of the worker node
 // that is responsible for handling the user's mailbox.
-func (f *FileAuthenticator) GetWorkerForUser(workers map[string]config.Worker, id int) (string, error) {
+func (f *File) GetWorkerForUser(workers map[string]config.Worker, id int) (string, error) {
 
 	for name, worker := range workers {
 
@@ -105,7 +105,7 @@ func (f *FileAuthenticator) GetWorkerForUser(workers map[string]config.Worker, i
 // process by taking supplied credentials and attempting
 // to find a matching entry the in-memory list taken from
 // the authentication file.
-func (f *FileAuthenticator) AuthenticatePlain(username string, password string, clientAddr string) (int, string, error) {
+func (f *File) AuthenticatePlain(username string, password string, clientAddr string) (int, string, error) {
 
 	// Search in user list for user matching supplied name.
 	i := sort.Search(len(f.Users), func(i int) bool {

imap/distributor.go

@@ -9,7 +9,6 @@ import (
 
 	"crypto/tls"
 
-	"github.com/numbleroot/pluto/auth"
 	"github.com/numbleroot/pluto/config"
 	"github.com/numbleroot/pluto/crypto"
 )
@@ -50,34 +49,18 @@ type Distributor struct {
 // opened up on supplied IP address and port as well as initializes
 // connections to involved worker nodes. It returns those
 // information bundeled in above Distributor struct.
-func InitDistributor(config *config.Config) (*Distributor, error) {
+func InitDistributor(config *config.Config, auth PlainAuthenticator) (*Distributor, error) {
 
 	var err error
 
 	// Initialize and set fields.
 	distr := &Distributor{
 		lock:        new(sync.RWMutex),
+		AuthAdapter: auth,
 		Connections: make(map[string]*tls.Conn),
 		Config:      config,
 	}
 
-	// As the distributor is responsible for the authentication
-	// of incoming requests, connect to provided auth mechanism.
-	if config.Distributor.AuthAdapter == "AuthFile" {
-
-		// Open authentication file and read user information.
-		distr.AuthAdapter, err = auth.NewFileAuthenticator(config.Distributor.AuthFile.File, config.Distributor.AuthFile.Separator)
-
-	} else if config.Distributor.AuthAdapter == "AuthPostgres" {
-
-		// Connect to PostgreSQL database.
-		distr.AuthAdapter, err = auth.NewPostgresAuthenticator(config.Distributor.AuthPostgres.IP, config.Distributor.AuthPostgres.Port, config.Distributor.AuthPostgres.Database, config.Distributor.AuthPostgres.User, config.Distributor.AuthPostgres.Password, config.Distributor.AuthPostgres.UseTLS)
-
-	}
-	if err != nil {
-		return nil, err
-	}
-
 	// Load internal TLS config.
 	distr.IntlTLSConfig, err = crypto.NewInternalTLSConfig(config.Distributor.InternalTLS.CertLoc, config.Distributor.InternalTLS.KeyLoc, config.RootCertLoc)
 	if err != nil {

main.go

@@ -6,12 +6,37 @@ import (
 	"os"
 	"runtime"
 
+	"github.com/numbleroot/pluto/auth"
 	"github.com/numbleroot/pluto/config"
 	"github.com/numbleroot/pluto/imap"
 )
 
 // Functions
 
+// initAuthenticator of the correct implementation specified in the config
+// to be used in the imap.Distributor.
+func initAuthenticator(config *config.Config) (imap.PlainAuthenticator, error) {
+
+	switch config.Distributor.AuthAdapter {
+	case "AuthPostgres":
+		// Connect to PostgreSQL database.
+		return auth.NewPostgresAuthenticator(
+			config.Distributor.AuthPostgres.IP,
+			config.Distributor.AuthPostgres.Port,
+			config.Distributor.AuthPostgres.Database,
+			config.Distributor.AuthPostgres.User,
+			config.Distributor.AuthPostgres.Password,
+			config.Distributor.AuthPostgres.UseTLS,
+		)
+	default: // AuthFile
+		// Open authentication file and read user information.
+		return auth.NewFile(
+			config.Distributor.AuthFile.File,
+			config.Distributor.AuthFile.Separator,
+		)
+	}
+}
+
 func main() {
 
 	var err error
@@ -37,8 +62,13 @@ func main() {
 	// system based on passed command line flag.
 	if *distributorFlag {
 
+		authenticator, err := initAuthenticator(conf)
+		if err != nil {
+			log.Fatal(err)
+		}
+
 		// Initialize distributor.
-		distr, err := imap.InitDistributor(conf)
+		distr, err := imap.InitDistributor(conf, authenticator)
 		if err != nil {
 			log.Fatal(err)
 		}