Refactor Caddyfile adapter and module registration

Use piles from which to draw config values.

Module values can return their name, so now we can do two-way mapping
from value to name and name to value; whereas before we could only map
name to value. This was problematic with the Caddyfile adapter since
it receives values and needs to know the name to put in the config.

6 files changed, 63 insertions, 33 deletions

diff --git a/modules/caddytls/acmemanager.go b/modules/caddytls/acmemanager.go
index 578cdb3..36f1c21 100644
--- a/modules/caddytls/acmemanager.go
+++ b/modules/caddytls/acmemanager.go
@@ -28,10 +28,7 @@ import (
 )
 
 func init() {
-	caddy.RegisterModule(caddy.Module{
-		Name: "tls.management.acme",
-		New:  func() interface{} { return new(ACMEManagerMaker) },
-	})
+	caddy.RegisterModule(ACMEManagerMaker{})
 }
 
 // ACMEManagerMaker makes an ACME manager
@@ -57,9 +54,17 @@ type ACMEManagerMaker struct {
 	keyType certcrypto.KeyType
 }
 
-// newManager is a no-op to satisfy the ManagerMaker interface,
+// CaddyModule returns the Caddy module information.
+func (ACMEManagerMaker) CaddyModule() caddy.ModuleInfo {
+	return caddy.ModuleInfo{
+		Name: "tls.management.acme",
+		New:  func() caddy.Module { return new(ACMEManagerMaker) },
+	}
+}
+
+// NewManager is a no-op to satisfy the ManagerMaker interface,
 // because this manager type is a special case.
-func (m *ACMEManagerMaker) newManager(interactive bool) (certmagic.Manager, error) {
+func (m ACMEManagerMaker) NewManager(interactive bool) (certmagic.Manager, error) {
 	return nil, nil
 }
 
@@ -203,4 +208,4 @@ func onDemandAskRequest(ask string, name string) error {
 }
 
 // Interface guard
-var _ managerMaker = (*ACMEManagerMaker)(nil)
+var _ ManagerMaker = (*ACMEManagerMaker)(nil)
diff --git a/modules/caddytls/fileloader.go b/modules/caddytls/fileloader.go
index 7a0d14d..b2cc132 100644
--- a/modules/caddytls/fileloader.go
+++ b/modules/caddytls/fileloader.go
@@ -23,15 +23,20 @@ import (
 )
 
 func init() {
-	caddy.RegisterModule(caddy.Module{
-		Name: "tls.certificates.load_files",
-		New:  func() interface{} { return FileLoader{} },
-	})
+	caddy.RegisterModule(FileLoader{})
 }
 
 // FileLoader loads certificates and their associated keys from disk.
 type FileLoader []CertKeyFilePair
 
+// CaddyModule returns the Caddy module information.
+func (FileLoader) CaddyModule() caddy.ModuleInfo {
+	return caddy.ModuleInfo{
+		Name: "tls.certificates.load_files",
+		New:  func() caddy.Module { return new(FileLoader) },
+	}
+}
+
 // CertKeyFilePair pairs certificate and key file names along with their
 // encoding format so that they can be loaded from disk.
 type CertKeyFilePair struct {
diff --git a/modules/caddytls/folderloader.go b/modules/caddytls/folderloader.go
index ae7f056..da1dff0 100644
--- a/modules/caddytls/folderloader.go
+++ b/modules/caddytls/folderloader.go
@@ -28,10 +28,7 @@ import (
 )
 
 func init() {
-	caddy.RegisterModule(caddy.Module{
-		Name: "tls.certificates.load_folders",
-		New:  func() interface{} { return FolderLoader{} },
-	})
+	caddy.RegisterModule(FolderLoader{})
 }
 
 // FolderLoader loads certificates and their associated keys from disk
@@ -39,6 +36,14 @@ func init() {
 // files which contain both a certificate and a key.
 type FolderLoader []string
 
+// CaddyModule returns the Caddy module information.
+func (FolderLoader) CaddyModule() caddy.ModuleInfo {
+	return caddy.ModuleInfo{
+		Name: "tls.certificates.load_folders",
+		New:  func() caddy.Module { return new(FolderLoader) },
+	}
+}
+
 // LoadCertificates loads all the certificates+keys in the directories
 // listed in fl from all files ending with .pem. This method of loading
 // certificates expects the certificate and key to be bundled into the
diff --git a/modules/caddytls/matchers.go b/modules/caddytls/matchers.go
index ee146d4..47fb296 100644
--- a/modules/caddytls/matchers.go
+++ b/modules/caddytls/matchers.go
@@ -20,14 +20,19 @@ import (
 	"github.com/caddyserver/caddy/v2"
 )
 
+func init() {
+	caddy.RegisterModule(MatchServerName{})
+}
+
 // MatchServerName matches based on SNI.
 type MatchServerName []string
 
-func init() {
-	caddy.RegisterModule(caddy.Module{
+// CaddyModule returns the Caddy module information.
+func (MatchServerName) CaddyModule() caddy.ModuleInfo {
+	return caddy.ModuleInfo{
 		Name: "tls.handshake_match.sni",
-		New:  func() interface{} { return MatchServerName{} },
-	})
+		New:  func() caddy.Module { return new(MatchServerName) },
+	}
 }
 
 // Match matches hello based on SNI.
diff --git a/modules/caddytls/standardstek/stek.go b/modules/caddytls/standardstek/stek.go
index 6a4b1c8..6d10c76 100644
--- a/modules/caddytls/standardstek/stek.go
+++ b/modules/caddytls/standardstek/stek.go
@@ -24,10 +24,7 @@ import (
 )
 
 func init() {
-	caddy.RegisterModule(caddy.Module{
-		Name: "tls.stek.standard",
-		New:  func() interface{} { return new(standardSTEKProvider) },
-	})
+	caddy.RegisterModule(standardSTEKProvider{})
 }
 
 type standardSTEKProvider struct {
@@ -35,6 +32,14 @@ type standardSTEKProvider struct {
 	timer      *time.Timer
 }
 
+// CaddyModule returns the Caddy module information.
+func (standardSTEKProvider) CaddyModule() caddy.ModuleInfo {
+	return caddy.ModuleInfo{
+		Name: "tls.stek.standard",
+		New:  func() caddy.Module { return new(standardSTEKProvider) },
+	}
+}
+
 // Initialize sets the configuration for s and returns the starting keys.
 func (s *standardSTEKProvider) Initialize(config *caddytls.SessionTicketService) ([][32]byte, error) {
 	// keep a reference to the config; we'll need it when rotating keys
diff --git a/modules/caddytls/tls.go b/modules/caddytls/tls.go
index ec16995..88b7790 100644
--- a/modules/caddytls/tls.go
+++ b/modules/caddytls/tls.go
@@ -30,10 +30,7 @@ import (
 )
 
 func init() {
-	caddy.RegisterModule(caddy.Module{
-		Name: "tls",
-		New:  func() interface{} { return new(TLS) },
-	})
+	caddy.RegisterModule(TLS{})
 
 	// opt-in TLS 1.3 for Go1.12
 	// TODO: remove this line when Go1.13 is released.
@@ -53,6 +50,14 @@ type TLS struct {
 	ctx                caddy.Context
 }
 
+// CaddyModule returns the Caddy module information.
+func (TLS) CaddyModule() caddy.ModuleInfo {
+	return caddy.ModuleInfo{
+		Name: "tls",
+		New:  func() caddy.Module { return new(TLS) },
+	}
+}
+
 // Provision sets up the configuration for the TLS app.
 func (t *TLS) Provision(ctx caddy.Context) error {
 	t.ctx = ctx
@@ -73,7 +78,7 @@ func (t *TLS) Provision(ctx caddy.Context) error {
 		if err != nil {
 			return fmt.Errorf("loading TLS automation management module: %s", err)
 		}
-		t.Automation.Policies[i].Management = val.(managerMaker)
+		t.Automation.Policies[i].Management = val.(ManagerMaker)
 		t.Automation.Policies[i].ManagementRaw = nil // allow GC to deallocate - TODO: Does this help?
 	}
 
@@ -237,7 +242,7 @@ type AutomationPolicy struct {
 	Hosts         []string        `json:"hosts,omitempty"`
 	ManagementRaw json.RawMessage `json:"management,omitempty"`
 
-	Management managerMaker `json:"-"`
+	Management ManagerMaker `json:"-"`
 }
 
 // makeCertMagicConfig converts ap into a CertMagic config. Passing onDemand
@@ -252,7 +257,7 @@ func (ap AutomationPolicy) makeCertMagicConfig(ctx caddy.Context) certmagic.Conf
 	}
 
 	return certmagic.Config{
-		NewManager: ap.Management.newManager,
+		NewManager: ap.Management.NewManager,
 	}
 }
 
@@ -290,9 +295,9 @@ type RateLimit struct {
 	Burst    int            `json:"burst,omitempty"`
 }
 
-// managerMaker makes a certificate manager.
-type managerMaker interface {
-	newManager(interactive bool) (certmagic.Manager, error)
+// ManagerMaker makes a certificate manager.
+type ManagerMaker interface {
+	NewManager(interactive bool) (certmagic.Manager, error)
 }
 
 // These perpetual values are used for on-demand TLS.