Files
sendico/api/pkg/messaging/internal/natsb/broker.go
2026-01-04 12:57:40 +01:00

149 lines
3.7 KiB
Go

package natsb
import (
"fmt"
"net"
"net/url"
"os"
"strconv"
"strings"
"sync"
"time"
"github.com/nats-io/nats.go"
"github.com/tech/sendico/pkg/merrors"
nc "github.com/tech/sendico/pkg/messaging/internal/natsb/config"
"github.com/tech/sendico/pkg/mlogger"
"go.uber.org/zap"
)
type natsSubscriotions = map[string]*TopicSubscription
type NatsBroker struct {
nc *nats.Conn
js nats.JetStreamContext
logger *zap.Logger
topicSubs natsSubscriotions
mu sync.Mutex
}
type envConfig struct {
User, Password, Host string
Port int
}
// loadEnv gathers and validates connection details from environment variables
// listed in the Settings struct. Invalid or missing values surface as a typed
// InvalidArgument error so callers can decide how to handle them.
func loadEnv(settings *nc.Settings, l *zap.Logger) (*envConfig, error) {
get := func(key, label string) (string, error) {
if v := os.Getenv(key); v != "" {
return v, nil
}
l.Error(fmt.Sprintf("NATS %s not found in environment", label), zap.String("env_var", key))
return "", merrors.InvalidArgument(fmt.Sprintf("NATS %s not found in environment variable: %s", label, key), key)
}
user, err := get(settings.UsernameEnv, "user name")
if err != nil {
return nil, err
}
password, err := get(settings.PasswordEnv, "password")
if err != nil {
return nil, err
}
host, err := get(settings.HostEnv, "host")
if err != nil {
return nil, err
}
portStr, err := get(settings.PortEnv, "port")
if err != nil {
return nil, err
}
port, err := strconv.Atoi(portStr)
if err != nil || port <= 0 || port > 65535 {
l.Error("Invalid NATS port value", zap.String("port", portStr))
return nil, merrors.InvalidArgument("Invalid NATS port: "+portStr, settings.PortEnv)
}
return &envConfig{
User: user,
Password: password,
Host: host,
Port: port,
}, nil
}
func NewNatsBroker(logger mlogger.Logger, settings *nc.Settings) (*NatsBroker, error) {
l := logger.Named("broker")
var err error
var cfg *envConfig
var natsURL string
if settings != nil && strings.TrimSpace(settings.URLEnv) != "" {
urlVal := strings.TrimSpace(os.Getenv(settings.URLEnv))
if urlVal != "" {
natsURL = urlVal
}
}
if natsURL == "" {
// Helper function to get environment variables
cfg, err = loadEnv(settings, l)
if err != nil {
return nil, err
}
u := &url.URL{
Scheme: "nats",
Host: net.JoinHostPort(cfg.Host, strconv.Itoa(cfg.Port)),
}
natsURL = u.String()
}
opts := []nats.Option{
nats.Name(settings.NATSName),
nats.MaxReconnects(settings.MaxReconnects),
nats.ReconnectWait(time.Duration(settings.ReconnectWait) * time.Second),
}
if cfg != nil {
opts = append(opts, nats.UserInfo(cfg.User, cfg.Password))
} else if settings != nil {
userEnv := strings.TrimSpace(settings.UsernameEnv)
passEnv := strings.TrimSpace(settings.PasswordEnv)
if userEnv != "" && passEnv != "" {
user := strings.TrimSpace(os.Getenv(userEnv))
pass := strings.TrimSpace(os.Getenv(passEnv))
if user != "" || pass != "" {
opts = append(opts, nats.UserInfo(user, pass))
}
}
}
res := &NatsBroker{
logger: l.Named("nats"),
topicSubs: natsSubscriotions{},
}
if res.nc, err = nats.Connect(natsURL, opts...); err != nil {
l.Error("Failed to connect to NATS", zap.String("url", natsURL), zap.Error(err))
return nil, err
}
if res.js, err = res.nc.JetStream(); err != nil {
l.Warn("Failed to initialise JetStream context", zap.Error(err))
}
logger.Info("Connected to NATS", zap.String("broker", settings.NATSName),
zap.String("url", natsURL))
return res, nil
}
func (b *NatsBroker) JetStream() nats.JetStreamContext {
if b == nil {
return nil
}
return b.js
}