add file and redis loader

auth/auth.go

@@ -1,27 +1,213 @@
 package auth
 
 import (
+	"bufio"
+	"context"
+	"io"
+	"strings"
+	"sync"
+	"time"
+
 	"github.com/go-gost/core/auth"
+	"github.com/go-gost/core/logger"
+	"github.com/go-gost/x/internal/loader"
 )
 
+type options struct {
+	auths       map[string]string
+	fileLoader  loader.Loader
+	redisLoader loader.Loader
+	period      time.Duration
+	logger      logger.Logger
+}
+
+type Option func(opts *options)
+
+func AuthsPeriodOption(auths map[string]string) Option {
+	return func(opts *options) {
+		opts.auths = auths
+	}
+}
+
+func ReloadPeriodOption(period time.Duration) Option {
+	return func(opts *options) {
+		opts.period = period
+	}
+}
+
+func FileLoaderOption(fileLoader loader.Loader) Option {
+	return func(opts *options) {
+		opts.fileLoader = fileLoader
+	}
+}
+
+func RedisLoaderOption(redisLoader loader.Loader) Option {
+	return func(opts *options) {
+		opts.redisLoader = redisLoader
+	}
+}
+
+func LoggerOption(logger logger.Logger) Option {
+	return func(opts *options) {
+		opts.logger = logger
+	}
+}
+
 // authenticator is an Authenticator that authenticates client by key-value pairs.
 type authenticator struct {
-	kvs map[string]string
+	kvs        map[string]string
+	mu         sync.RWMutex
+	cancelFunc context.CancelFunc
+	options    options
 }
 
 // NewAuthenticator creates an Authenticator that authenticates client by pre-defined user mapping.
-func NewAuthenticator(kvs map[string]string) auth.Authenticator {
-	return &authenticator{
-		kvs: kvs,
+func NewAuthenticator(opts ...Option) auth.Authenticator {
+	var options options
+	for _, opt := range opts {
+		opt(&options)
 	}
+
+	ctx, cancel := context.WithCancel(context.TODO())
+	p := &authenticator{
+		kvs:        make(map[string]string),
+		cancelFunc: cancel,
+		options:    options,
+	}
+
+	if err := p.reload(ctx); err != nil {
+		options.logger.Warnf("reload: %v", err)
+	}
+	if p.options.period > 0 {
+		go p.periodReload(ctx)
+	}
+
+	return p
 }
 
 // Authenticate checks the validity of the provided user-password pair.
-func (au *authenticator) Authenticate(user, password string) bool {
-	if au == nil || len(au.kvs) == 0 {
+func (p *authenticator) Authenticate(user, password string) bool {
+	if p == nil || len(p.kvs) == 0 {
 		return true
 	}
 
-	v, ok := au.kvs[user]
+	p.mu.RLock()
+	defer p.mu.RUnlock()
+
+	v, ok := p.kvs[user]
 	return ok && (v == "" || password == v)
 }
+
+func (p *authenticator) periodReload(ctx context.Context) error {
+	period := p.options.period
+	if period < time.Second {
+		period = time.Second
+	}
+	ticker := time.NewTicker(period)
+	defer ticker.Stop()
+
+	for {
+		select {
+		case <-ticker.C:
+			if err := p.reload(ctx); err != nil {
+				p.options.logger.Warnf("reload: %v", err)
+				// return err
+			}
+			p.options.logger.Debugf("auther reload done")
+		case <-ctx.Done():
+			return ctx.Err()
+		}
+	}
+}
+
+func (p *authenticator) reload(ctx context.Context) error {
+	kvs := make(map[string]string)
+	for k, v := range p.options.auths {
+		kvs[k] = v
+	}
+
+	m, err := p.load(ctx)
+	if err != nil {
+		return err
+	}
+	for k, v := range m {
+		kvs[k] = v
+	}
+
+	p.mu.Lock()
+	defer p.mu.Unlock()
+
+	p.kvs = kvs
+
+	return nil
+}
+
+func (p *authenticator) load(ctx context.Context) (m map[string]string, err error) {
+	m = make(map[string]string)
+
+	if p.options.fileLoader != nil {
+		r, er := p.options.fileLoader.Load(ctx)
+		if er != nil {
+			p.options.logger.Warnf("file loader: %v", er)
+		}
+		if auths, _ := p.parseAuths(r); auths != nil {
+			for k, v := range auths {
+				m[k] = v
+			}
+		}
+	}
+	if p.options.redisLoader != nil {
+		r, er := p.options.redisLoader.Load(ctx)
+		if er != nil {
+			p.options.logger.Warnf("redis loader: %v", er)
+		}
+		if auths, _ := p.parseAuths(r); auths != nil {
+			for k, v := range auths {
+				m[k] = v
+			}
+		}
+	}
+
+	return
+}
+
+func (p *authenticator) parseAuths(r io.Reader) (auths map[string]string, err error) {
+	if r == nil {
+		return
+	}
+
+	auths = make(map[string]string)
+
+	scanner := bufio.NewScanner(r)
+	for scanner.Scan() {
+		line := scanner.Text()
+		if n := strings.IndexByte(line, '#'); n >= 0 {
+			line = line[:n]
+		}
+		sp := strings.SplitN(strings.TrimSpace(line), " ", 2)
+		if len(sp) == 1 {
+			if k := strings.TrimSpace(sp[0]); k != "" {
+				auths[k] = ""
+			}
+		}
+		if len(sp) == 2 {
+			if k := strings.TrimSpace(sp[0]); k != "" {
+				auths[k] = strings.TrimSpace(sp[1])
+			}
+		}
+	}
+
+	err = scanner.Err()
+	return
+}
+
+func (p *authenticator) Close() error {
+	p.cancelFunc()
+	if p.options.fileLoader != nil {
+		p.options.fileLoader.Close()
+	}
+	if p.options.redisLoader != nil {
+		p.options.redisLoader.Close()
+	}
+	return nil
+}