refactor: better infrastructure for transports as Caddy modules (#975)

Author: dunglas

caddy/bolt.go

@@ -46,26 +46,26 @@ func (b *Bolt) Provision(ctx caddy.Context) error {
 	}
 	b.transportKey = key.String()
 
-	destructor, _, err := transport.LoadOrNew(b.transportKey, func() (caddy.Destructor, error) {
+	destructor, _, err := TransportUsagePool.LoadOrNew(b.transportKey, func() (caddy.Destructor, error) {
 		t, err := mercure.NewBoltTransport(ctx.Logger(), b.Path, b.BucketName, b.Size, b.CleanupFrequency)
 		if err != nil {
 			return nil, err
 		}
 
-		return transportDestructor[*mercure.BoltTransport]{transport: t}, nil
+		return TransportDestructor[*mercure.BoltTransport]{Transport: t}, nil
 	})
 	if err != nil {
 		return err
 	}
 
-	b.transport = destructor.(transportDestructor[*mercure.BoltTransport]).transport
+	b.transport = destructor.(TransportDestructor[*mercure.BoltTransport]).Transport
 
 	return nil
 }
 
 //nolint:wrapcheck
 func (b *Bolt) Cleanup() error {
-	_, err := transport.Delete(b.transportKey)
+	_, err := TransportUsagePool.Delete(b.transportKey)
 
 	return err
 }

caddy/local.go

@@ -30,20 +30,20 @@ func (l *Local) GetTransport() mercure.Transport { //nolint:ireturn
 	return l.transport
 }
 
-// Provision provisions b's configuration.
+// Provision provisions l's configuration.
 func (l *Local) Provision(_ caddy.Context) error {
-	destructor, _, _ := transport.LoadOrNew(localTransportKey, func() (caddy.Destructor, error) {
-		return transportDestructor[*mercure.LocalTransport]{transport: mercure.NewLocalTransport()}, nil
+	destructor, _, _ := TransportUsagePool.LoadOrNew(localTransportKey, func() (caddy.Destructor, error) {
+		return TransportDestructor[*mercure.LocalTransport]{Transport: mercure.NewLocalTransport()}, nil
 	})
 
-	l.transport = destructor.(transportDestructor[*mercure.LocalTransport]).transport
+	l.transport = destructor.(TransportDestructor[*mercure.LocalTransport]).Transport
 
 	return nil
 }
 
 //nolint:wrapcheck
 func (l *Local) Cleanup() error {
-	_, err := transport.Delete(localTransportKey)
+	_, err := TransportUsagePool.Delete(localTransportKey)
 
 	return err
 }

caddy/mercure.go

@@ -178,13 +178,13 @@ func createTransportLegacy(m *Mercure) (mercure.Transport, error) {
 			return nil, err
 		}
 
-		return &transportDestructor[mercure.Transport]{transport}, nil
+		return &TransportDestructor[mercure.Transport]{transport}, nil
 	})
 	if err != nil {
 		return nil, err
 	}
 
-	return destructor.(*transportDestructor[mercure.Transport]).transport, nil
+	return destructor.(*TransportDestructor[mercure.Transport]).Transport, nil
 }
 
 //nolint:wrapcheck
@@ -203,6 +203,9 @@ func (m *Mercure) Provision(ctx caddy.Context) error { //nolint:funlen,gocognit
 		return err
 	}
 
+	ctx = ctx.WithValue(SubscriptionsContextKey, m.Subscriptions)
+	ctx = ctx.WithValue(WriteTimeoutContextKey, m.WriteTimeout)
+
 	m.logger = ctx.Logger()
 
 	var transport mercure.Transport
@@ -411,21 +414,17 @@ func (m *Mercure) UnmarshalCaddyfile(d *caddyfile.Dispenser) error { //nolint:fu
 				}
 
 			case "publish_origins":
-				ra := d.RemainingArgs()
-				if len(ra) == 0 {
+				m.PublishOrigins = d.RemainingArgs()
+				if len(m.PublishOrigins) == 0 {
 					return d.ArgErr()
 				}
 
-				m.PublishOrigins = ra
-
 			case "cors_origins":
-				ra := d.RemainingArgs()
-				if len(ra) == 0 {
+				m.CORSOrigins = d.RemainingArgs()
+				if len(m.CORSOrigins) == 0 {
 					return d.ArgErr()
 				}
 
-				m.CORSOrigins = ra
-
 			case "transport":
 				if !d.NextArg() {
 					return d.ArgErr()

caddy/transport.go

@@ -5,16 +5,26 @@ import (
 	"github.com/dunglas/mercure"
 )
 
-var transport = caddy.NewUsagePool() //nolint:gochecknoglobals
+var TransportUsagePool = caddy.NewUsagePool() //nolint:gochecknoglobals
 
 type Transport interface {
 	GetTransport() mercure.Transport
 }
 
-type transportDestructor[T mercure.Transport] struct {
-	transport T
+type TransportDestructor[T mercure.Transport] struct {
+	Transport T
 }
 
-func (d transportDestructor[T]) Destruct() error {
-	return d.transport.Close() //nolint:wrapcheck
+func (d TransportDestructor[T]) Destruct() error {
+	return d.Transport.Close() //nolint:wrapcheck
 }
+
+type (
+	subscriptionsKeyType struct{}
+	writeTimeoutKeyType  struct{}
+)
+
+var (
+	SubscriptionsContextKey = subscriptionsKeyType{} //nolint:gochecknoglobals
+	WriteTimeoutContextKey  = writeTimeoutKeyType{}  //nolint:gochecknoglobals
+)