Implement notifications service with shared messaging and email drivers (#36)

backend/notifications/app/run.go

@@ -0,0 +1,105 @@
+package app
+
+import (
+	"context"
+	"crypto/tls"
+	"net"
+	"os"
+	"sync"
+	"time"
+
+	"git.sendico.io/tech/sxchnge/notifications/bus"
+	"git.sendico.io/tech/sxchnge/notifications/email"
+	pb "git.sendico.io/tech/sxchnge/notifications/interface/notifications/v1"
+	"git.sendico.io/tech/sxchnge/notifications/service"
+	"git.sendico.io/tech/sxchnge/notifications/store"
+	"git.sendico.io/tech/sxchnge/notifications/templates"
+	"git.sendico.io/tech/sxchnge/notifications/transport"
+	db "git.sendico.io/tech/sxchnge/shared/database"
+	merrors "git.sendico.io/tech/sxchnge/shared/errors"
+	mlogger "git.sendico.io/tech/sxchnge/shared/logging"
+	msgruntime "git.sendico.io/tech/sxchnge/shared/messaging/runtime"
+	"go.uber.org/zap"
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/credentials"
+)
+
+func Run(ctx context.Context, c Config, logger mlogger.Logger) error {
+	catalog, err := templates.Load(c.Templates)
+	if err != nil {
+		return err
+	}
+	sender, err := email.New(c.Email)
+	if err != nil {
+		return err
+	}
+	cert, err := tls.LoadX509KeyPair(c.TLSCert, c.TLSKey)
+	if err != nil {
+		return merrors.OpaqueWrap(merrors.ErrInvalidArg, err, "invalid gRPC TLS certificate")
+	}
+	client, err := db.ConnectMongo(logger, &c.Database)
+	if err != nil {
+		return merrors.OpaqueWrap(merrors.ErrServiceUnavailable, err, "connect notifications database")
+	}
+	defer func() {
+		cleanup, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+		defer cancel()
+		_ = client.Disconnect(cleanup)
+	}()
+	startup, cancel := context.WithTimeout(ctx, 20*time.Second)
+	defer cancel()
+	repo, err := store.New(logger, client.Database())
+	if err != nil {
+		return err
+	}
+	rt, err := msgruntime.New(logger, &c.Messaging)
+	if err != nil {
+		return err
+	}
+	defer rt.Close()
+	svc := service.New(repo, catalog, sender, string(c.Email.Driver), logger)
+	broker, err := bus.New(startup, rt.Durable, rt.DurableAdmin, repo, svc, logger)
+	if err != nil {
+		return err
+	}
+	defer broker.Close()
+	tokens := map[string]string{}
+	for caller, env := range c.Callers {
+		tokens[caller] = os.Getenv(env)
+	}
+	server := grpc.NewServer(grpc.Creds(credentials.NewTLS(&tls.Config{Certificates: []tls.Certificate{cert}, MinVersion: tls.VersionTLS12})), grpc.UnaryInterceptor(transport.Authenticate(tokens)), grpc.MaxRecvMsgSize(128<<10), grpc.MaxConcurrentStreams(64))
+	pb.RegisterNotificationsServiceServer(server, transport.New(svc))
+	listener, err := net.Listen("tcp", c.Listen)
+	if err != nil {
+		return merrors.OpaqueWrap(merrors.ErrServiceUnavailable, err, "listen for notifications")
+	}
+	defer listener.Close()
+	runCtx, stop := context.WithCancel(ctx)
+	defer stop()
+	var wg sync.WaitGroup
+	for _, run := range []func(context.Context){broker.RunPublisher, broker.RunWorker} {
+		wg.Add(1)
+		go func() { defer wg.Done(); run(runCtx) }()
+	}
+	serveErr := make(chan error, 1)
+	go func() { serveErr <- server.Serve(listener) }()
+	logger.Info("Notifications service started", zap.String("listen", c.Listen), zap.String("email_driver", string(c.Email.Driver)))
+	select {
+	case <-ctx.Done():
+	case err = <-serveErr:
+	}
+	stop()
+	stopped := make(chan struct{})
+	go func() { server.GracefulStop(); close(stopped) }()
+	select {
+	case <-stopped:
+	case <-time.After(5 * time.Second):
+		server.Stop()
+	}
+	wg.Wait()
+	if err != nil {
+		return merrors.OpaqueWrap(merrors.ErrInternal, err, "notification server stopped unexpectedly")
+	}
+	logger.Info("Notifications service stopped")
+	return nil
+}