feat: authsession service

authsession/internal/adapters/redis/configprovider/store.go

@@ -0,0 +1,169 @@
+// Package configprovider implements ports.ConfigProvider with Redis-backed
+// dynamic auth/session configuration.
+package configprovider
+
+import (
+	"context"
+	"crypto/tls"
+	"errors"
+	"fmt"
+	"strconv"
+	"strings"
+	"time"
+
+	"galaxy/authsession/internal/ports"
+
+	"github.com/redis/go-redis/v9"
+)
+
+// Config configures one Redis-backed config provider instance.
+type Config struct {
+	// Addr is the Redis network address in host:port form.
+	Addr string
+
+	// Username is the optional Redis ACL username.
+	Username string
+
+	// Password is the optional Redis ACL password.
+	Password string
+
+	// DB is the Redis logical database index.
+	DB int
+
+	// TLSEnabled enables TLS with a conservative minimum protocol version.
+	TLSEnabled bool
+
+	// SessionLimitKey identifies the single Redis string key that stores the
+	// active-session-limit configuration value.
+	SessionLimitKey string
+
+	// OperationTimeout bounds each Redis round trip performed by the adapter.
+	OperationTimeout time.Duration
+}
+
+// Store reads dynamic auth/session configuration from Redis.
+type Store struct {
+	client           *redis.Client
+	sessionLimitKey  string
+	operationTimeout time.Duration
+}
+
+// New constructs a Redis-backed config provider from cfg.
+func New(cfg Config) (*Store, error) {
+	switch {
+	case strings.TrimSpace(cfg.Addr) == "":
+		return nil, errors.New("new redis config provider: redis addr must not be empty")
+	case cfg.DB < 0:
+		return nil, errors.New("new redis config provider: redis db must not be negative")
+	case strings.TrimSpace(cfg.SessionLimitKey) == "":
+		return nil, errors.New("new redis config provider: session limit key must not be empty")
+	case cfg.OperationTimeout <= 0:
+		return nil, errors.New("new redis config provider: operation timeout must be positive")
+	}
+
+	options := &redis.Options{
+		Addr:            cfg.Addr,
+		Username:        cfg.Username,
+		Password:        cfg.Password,
+		DB:              cfg.DB,
+		Protocol:        2,
+		DisableIdentity: true,
+	}
+	if cfg.TLSEnabled {
+		options.TLSConfig = &tls.Config{MinVersion: tls.VersionTLS12}
+	}
+
+	return &Store{
+		client:           redis.NewClient(options),
+		sessionLimitKey:  cfg.SessionLimitKey,
+		operationTimeout: cfg.OperationTimeout,
+	}, nil
+}
+
+// Close releases the underlying Redis client resources.
+func (s *Store) Close() error {
+	if s == nil || s.client == nil {
+		return nil
+	}
+
+	return s.client.Close()
+}
+
+// Ping verifies that the configured Redis backend is reachable within the
+// adapter operation timeout budget.
+func (s *Store) Ping(ctx context.Context) error {
+	operationCtx, cancel, err := s.operationContext(ctx, "ping redis config provider")
+	if err != nil {
+		return err
+	}
+	defer cancel()
+
+	if err := s.client.Ping(operationCtx).Err(); err != nil {
+		return fmt.Errorf("ping redis config provider: %w", err)
+	}
+
+	return nil
+}
+
+// LoadSessionLimit returns the current active-session-limit configuration.
+// Missing or invalid Redis values are treated as “limit absent” by policy.
+func (s *Store) LoadSessionLimit(ctx context.Context) (ports.SessionLimitConfig, error) {
+	operationCtx, cancel, err := s.operationContext(ctx, "load session limit from redis")
+	if err != nil {
+		return ports.SessionLimitConfig{}, err
+	}
+	defer cancel()
+
+	value, err := s.client.Get(operationCtx, s.sessionLimitKey).Result()
+	switch {
+	case errors.Is(err, redis.Nil):
+		return ports.SessionLimitConfig{}, nil
+	case err != nil:
+		return ports.SessionLimitConfig{}, fmt.Errorf("load session limit from redis: %w", err)
+	}
+
+	config, valid := parseSessionLimitConfig(value)
+	if !valid {
+		return ports.SessionLimitConfig{}, nil
+	}
+	if err := config.Validate(); err != nil {
+		return ports.SessionLimitConfig{}, nil
+	}
+
+	return config, nil
+}
+
+func (s *Store) operationContext(ctx context.Context, operation string) (context.Context, context.CancelFunc, error) {
+	if s == nil || s.client == nil {
+		return nil, nil, fmt.Errorf("%s: nil store", operation)
+	}
+	if ctx == nil {
+		return nil, nil, fmt.Errorf("%s: nil context", operation)
+	}
+
+	operationCtx, cancel := context.WithTimeout(ctx, s.operationTimeout)
+	return operationCtx, cancel, nil
+}
+
+func parseSessionLimitConfig(raw string) (ports.SessionLimitConfig, bool) {
+	if strings.TrimSpace(raw) == "" || strings.TrimSpace(raw) != raw {
+		return ports.SessionLimitConfig{}, false
+	}
+	for _, symbol := range raw {
+		if symbol < '0' || symbol > '9' {
+			return ports.SessionLimitConfig{}, false
+		}
+	}
+
+	parsed, err := strconv.ParseInt(raw, 10, strconv.IntSize)
+	if err != nil || parsed <= 0 {
+		return ports.SessionLimitConfig{}, false
+	}
+
+	limit := int(parsed)
+	return ports.SessionLimitConfig{
+		ActiveSessionLimit: &limit,
+	}, true
+}
+
+var _ ports.ConfigProvider = (*Store)(nil)