feat: use postgres

pkg/redisconn/config.go

@@ -0,0 +1,187 @@
+// Package redisconn provides shared helpers for opening, instrumenting and
+// pinging Redis connections used by Galaxy services.
+//
+// The package codifies the steady-state rules captured in `ARCHITECTURE.md`
+// `§Persistence Backends`: each service connects to one master plus
+// zero-or-more replicas with a mandatory password, no TLS, and no
+// `USERNAME`/ACL. The deprecated env vars `*_REDIS_TLS_ENABLED` and
+// `*_REDIS_USERNAME` are rejected by LoadFromEnv with a clear startup error.
+package redisconn
+
+import (
+	"errors"
+	"fmt"
+	"os"
+	"strconv"
+	"strings"
+	"time"
+)
+
+// Default configuration values applied by DefaultConfig and LoadFromEnv when
+// the corresponding environment variable is absent.
+const (
+	DefaultDB               = 0
+	DefaultOperationTimeout = 250 * time.Millisecond
+)
+
+// Config stores the connection settings for one master plus zero-or-more
+// replica Redis instances. Stage 1 wires only the master; the replica list is
+// preserved so future read-routing is a non-breaking change.
+type Config struct {
+	// MasterAddr stores the Redis network address in host:port form. Required.
+	MasterAddr string
+
+	// ReplicaAddrs stores zero-or-more read-only replica addresses.
+	ReplicaAddrs []string
+
+	// Password is the mandatory connection password. Empty values are rejected
+	// by Validate to enforce the architectural rule that Redis traffic is
+	// password-protected even on the trusted segment.
+	Password string
+
+	// DB selects the logical Redis database index.
+	DB int
+
+	// OperationTimeout bounds individual Redis round trips.
+	OperationTimeout time.Duration
+}
+
+// DefaultConfig returns the default tuning. MasterAddr and Password remain
+// zero-valued and must be supplied by callers (or by LoadFromEnv).
+func DefaultConfig() Config {
+	return Config{
+		DB:               DefaultDB,
+		OperationTimeout: DefaultOperationTimeout,
+	}
+}
+
+// Validate reports whether cfg is usable.
+func (cfg Config) Validate() error {
+	if strings.TrimSpace(cfg.MasterAddr) == "" {
+		return errors.New("redis master addr must not be empty")
+	}
+	if strings.TrimSpace(cfg.Password) == "" {
+		return errors.New("redis password must not be empty")
+	}
+	for index, addr := range cfg.ReplicaAddrs {
+		if strings.TrimSpace(addr) == "" {
+			return fmt.Errorf("redis replica addr at index %d must not be empty", index)
+		}
+	}
+	if cfg.DB < 0 {
+		return errors.New("redis db must not be negative")
+	}
+	if cfg.OperationTimeout <= 0 {
+		return errors.New("redis operation timeout must be positive")
+	}
+	return nil
+}
+
+// LoadFromEnv populates Config from environment variables prefixed with
+// `<prefix>_REDIS_`. The required variables are
+// `<prefix>_REDIS_MASTER_ADDR` and `<prefix>_REDIS_PASSWORD`; every other
+// variable falls back to DefaultConfig values.
+//
+// LoadFromEnv hard-fails when either of the deprecated variables
+// `<prefix>_REDIS_TLS_ENABLED` or `<prefix>_REDIS_USERNAME` is set in the
+// environment, with an error pointing to ARCHITECTURE.md.
+func LoadFromEnv(prefix string) (Config, error) {
+	if strings.TrimSpace(prefix) == "" {
+		return Config{}, errors.New("redis env prefix must not be empty")
+	}
+
+	if err := rejectDeprecatedEnv(prefix); err != nil {
+		return Config{}, err
+	}
+
+	cfg := DefaultConfig()
+
+	masterName := envName(prefix, "MASTER_ADDR")
+	master, ok := os.LookupEnv(masterName)
+	if !ok || strings.TrimSpace(master) == "" {
+		return Config{}, fmt.Errorf("%s must be set", masterName)
+	}
+	cfg.MasterAddr = strings.TrimSpace(master)
+
+	passwordName := envName(prefix, "PASSWORD")
+	password, ok := os.LookupEnv(passwordName)
+	if !ok || strings.TrimSpace(password) == "" {
+		return Config{}, fmt.Errorf("%s must be set", passwordName)
+	}
+	cfg.Password = strings.TrimSpace(password)
+
+	if raw, ok := os.LookupEnv(envName(prefix, "REPLICA_ADDRS")); ok {
+		cfg.ReplicaAddrs = splitCSV(raw)
+	}
+
+	db, err := loadInt(envName(prefix, "DB"), cfg.DB)
+	if err != nil {
+		return Config{}, err
+	}
+	cfg.DB = db
+
+	timeout, err := loadDuration(envName(prefix, "OPERATION_TIMEOUT"), cfg.OperationTimeout)
+	if err != nil {
+		return Config{}, err
+	}
+	cfg.OperationTimeout = timeout
+
+	if err := cfg.Validate(); err != nil {
+		return Config{}, err
+	}
+	return cfg, nil
+}
+
+func rejectDeprecatedEnv(prefix string) error {
+	for _, suffix := range []string{"TLS_ENABLED", "USERNAME"} {
+		name := envName(prefix, suffix)
+		if _, ok := os.LookupEnv(name); ok {
+			return fmt.Errorf("%s is no longer supported (see ARCHITECTURE.md §Persistence Backends); unset it before starting the service", name)
+		}
+	}
+	return nil
+}
+
+func envName(prefix, suffix string) string {
+	return strings.ToUpper(strings.TrimSpace(prefix)) + "_REDIS_" + suffix
+}
+
+func splitCSV(raw string) []string {
+	parts := strings.Split(raw, ",")
+	out := make([]string, 0, len(parts))
+	for _, part := range parts {
+		trimmed := strings.TrimSpace(part)
+		if trimmed == "" {
+			continue
+		}
+		out = append(out, trimmed)
+	}
+	if len(out) == 0 {
+		return nil
+	}
+	return out
+}
+
+func loadDuration(name string, fallback time.Duration) (time.Duration, error) {
+	raw, ok := os.LookupEnv(name)
+	if !ok {
+		return fallback, nil
+	}
+	parsed, err := time.ParseDuration(strings.TrimSpace(raw))
+	if err != nil {
+		return 0, fmt.Errorf("%s: %w", name, err)
+	}
+	return parsed, nil
+}
+
+func loadInt(name string, fallback int) (int, error) {
+	raw, ok := os.LookupEnv(name)
+	if !ok {
+		return fallback, nil
+	}
+	parsed, err := strconv.Atoi(strings.TrimSpace(raw))
+	if err != nil {
+		return 0, fmt.Errorf("%s: %w", name, err)
+	}
+	return parsed, nil
+}