Apply global DNS module to ACME challenges

This allows DNS challenges to be enabled without locally-configured DNS modules

caddyconfig/httpcaddyfile/builtins.go

@@ -99,7 +99,7 @@ func parseBind(h Helper) ([]ConfigValue, error) {
 //	    ca                            <acme_ca_endpoint>
 //	    ca_root                       <pem_file>
 //	    key_type                      [ed25519|p256|p384|rsa2048|rsa4096]
-//	    dns                           <provider_name> [...]
+//	    dns                           [<provider_name> [...]]    (required, though, if DNS is not configured as global option)
 //	    propagation_delay             <duration>
 //	    propagation_timeout           <duration>
 //	    resolvers                     <dns_servers...>
@@ -312,10 +312,6 @@ func parseTLS(h Helper) ([]ConfigValue, error) {
 			certManagers = append(certManagers, certManager)
 
 		case "dns":
-			if !h.NextArg() {
-				return nil, h.ArgErr()
-			}
-			provName := h.Val()
 			if acmeIssuer == nil {
 				acmeIssuer = new(caddytls.ACMEIssuer)
 			}
@@ -325,12 +321,19 @@ func parseTLS(h Helper) ([]ConfigValue, error) {
 			if acmeIssuer.Challenges.DNS == nil {
 				acmeIssuer.Challenges.DNS = new(caddytls.DNSChallengeConfig)
 			}
-			modID := "dns.providers." + provName
-			unm, err := caddyfile.UnmarshalModule(h.Dispenser, modID)
-			if err != nil {
-				return nil, err
+			// DNS provider configuration optional, since it may be configured globally via the TLS app with global options
+			if h.NextArg() {
+				provName := h.Val()
+				modID := "dns.providers." + provName
+				unm, err := caddyfile.UnmarshalModule(h.Dispenser, modID)
+				if err != nil {
+					return nil, err
+				}
+				acmeIssuer.Challenges.DNS.ProviderRaw = caddyconfig.JSONModuleObject(unm, "name", provName, h.warnings)
+			} else if h.Option("dns") == nil {
+				// if DNS is omitted locally, it needs to be configured globally
+				return nil, h.ArgErr()
 			}
-			acmeIssuer.Challenges.DNS.ProviderRaw = caddyconfig.JSONModuleObject(unm, "name", provName, h.warnings)
 
 		case "resolvers":
 			args := h.RemainingArgs()

caddyconfig/httpcaddyfile/tlsapp.go

@@ -577,7 +577,8 @@ func fillInGlobalACMEDefaults(issuer certmagic.Issuer, options map[string]any) e
 	if globalPreferredChains != nil && acmeIssuer.PreferredChains == nil {
 		acmeIssuer.PreferredChains = globalPreferredChains.(*caddytls.ChainPreference)
 	}
-	if globalHTTPPort != nil && (acmeIssuer.Challenges == nil || acmeIssuer.Challenges.HTTP == nil || acmeIssuer.Challenges.HTTP.AlternatePort == 0) {
+	// only configure alt HTTP and TLS-ALPN ports if the DNS challenge is not enabled (wouldn't hurt, but isn't necessary since the DNS challenge is exclusive of others)
+	if globalHTTPPort != nil && (acmeIssuer.Challenges == nil || acmeIssuer.Challenges.DNS == nil) && (acmeIssuer.Challenges == nil || acmeIssuer.Challenges.HTTP == nil || acmeIssuer.Challenges.HTTP.AlternatePort == 0) {
 		if acmeIssuer.Challenges == nil {
 			acmeIssuer.Challenges = new(caddytls.ChallengesConfig)
 		}
@@ -586,7 +587,7 @@ func fillInGlobalACMEDefaults(issuer certmagic.Issuer, options map[string]any) e
 		}
 		acmeIssuer.Challenges.HTTP.AlternatePort = globalHTTPPort.(int)
 	}
-	if globalHTTPSPort != nil && (acmeIssuer.Challenges == nil || acmeIssuer.Challenges.TLSALPN == nil || acmeIssuer.Challenges.TLSALPN.AlternatePort == 0) {
+	if globalHTTPSPort != nil && (acmeIssuer.Challenges == nil || acmeIssuer.Challenges.DNS == nil) && (acmeIssuer.Challenges == nil || acmeIssuer.Challenges.TLSALPN == nil || acmeIssuer.Challenges.TLSALPN.AlternatePort == 0) {
 		if acmeIssuer.Challenges == nil {
 			acmeIssuer.Challenges = new(caddytls.ChallengesConfig)
 		}

context.go

@@ -385,6 +385,17 @@ func (ctx Context) LoadModuleByID(id string, rawMsg json.RawMessage) (any, error
 		return nil, fmt.Errorf("module value cannot be null")
 	}
 
+	// if this is an app module, keep a reference to it,
+	// since submodules may need to reference it during
+	// provisioning (even though the parent app module
+	// may not be fully provisioned yet; this is the case
+	// with the tls app's automation policies, which may
+	// refer to the tls app to check if a global DNS
+	// module has been configured for DNS challenges)
+	if appModule, ok := val.(App); ok {
+		ctx.cfg.apps[id] = appModule
+	}
+
 	ctx.ancestry = append(ctx.ancestry, val)
 
 	if prov, ok := val.(Provisioner); ok {
@@ -471,7 +482,6 @@ func (ctx Context) App(name string) (any, error) {
 	if appRaw != nil {
 		ctx.cfg.AppsRaw[name] = nil // allow GC to deallocate
 	}
-	ctx.cfg.apps[name] = modVal.(App)
 	return modVal, nil
 }
 

modules/caddytls/acmeissuer.go

@@ -146,15 +146,30 @@ func (iss *ACMEIssuer) Provision(ctx caddy.Context) error {
 		iss.AccountKey = accountKey
 	}
 
-	// DNS providers
-	if iss.Challenges != nil && iss.Challenges.DNS != nil && iss.Challenges.DNS.ProviderRaw != nil {
-		val, err := ctx.LoadModule(iss.Challenges.DNS, "ProviderRaw")
-		if err != nil {
-			return fmt.Errorf("loading DNS provider module: %v", err)
+	// DNS challenge provider
+	if iss.Challenges != nil && iss.Challenges.DNS != nil {
+		var prov certmagic.DNSProvider
+		if iss.Challenges.DNS.ProviderRaw != nil {
+			// a challenge provider has been locally configured - use it
+			val, err := ctx.LoadModule(iss.Challenges.DNS, "ProviderRaw")
+			if err != nil {
+				return fmt.Errorf("loading DNS provider module: %v", err)
+			}
+			prov = val.(certmagic.DNSProvider)
+		} else if tlsAppIface, err := ctx.AppIfConfigured("tls"); err == nil {
+			// no locally configured DNS challenge provider, but if there is
+			// a global DNS module configured with the TLS app, use that
+			tlsApp := tlsAppIface.(*TLS)
+			if tlsApp.dns != nil {
+				prov = tlsApp.dns.(certmagic.DNSProvider)
+			}
+		}
+		if prov == nil {
+			return fmt.Errorf("DNS challenge enabled, but no DNS provider configured")
 		}
 		iss.Challenges.DNS.solver = &certmagic.DNS01Solver{
 			DNSManager: certmagic.DNSManager{
-				DNSProvider:        val.(certmagic.DNSProvider),
+				DNSProvider:        prov,
 				TTL:                time.Duration(iss.Challenges.DNS.TTL),
 				PropagationDelay:   time.Duration(iss.Challenges.DNS.PropagationDelay),
 				PropagationTimeout: time.Duration(iss.Challenges.DNS.PropagationTimeout),

modules/caddytls/ech.go

@@ -242,6 +242,9 @@ func (t *TLS) publishECHConfigs() error {
 			// if all the (inner) domains have had this ECH config list published
 			// by this publisher, then try the next publication config
 			if len(serverNamesSet) == 0 {
+				logger.Debug("ECH config list already published by publisher for associated domains",
+					zap.Uint8s("config_ids", configIDs),
+					zap.String("publisher", publisherKey))
 				continue
 			}
 
@@ -252,7 +255,7 @@ func (t *TLS) publishECHConfigs() error {
 			}
 
 			logger.Debug("publishing ECH config list",
-				zap.Strings("inner_names", dnsNamesToPublish),
+				zap.Strings("domains", dnsNamesToPublish),
 				zap.Uint8s("config_ids", configIDs))
 
 			// publish this ECH config list with this publisher
@@ -1045,22 +1048,6 @@ type echConfigMeta struct {
 // map of inner name to timestamp
 type publicationHistory map[string]map[string]time.Time
 
-func (hist publicationHistory) unpublishedNames(publisherKey string, serverNamesSet map[string]struct{}) map[string]struct{} {
-	innerNamesSet, ok := hist[publisherKey]
-	if !ok {
-		// no history of this publisher publishing this config at all, so publish for entire set of names
-		return serverNamesSet
-	}
-	for innerName := range innerNamesSet {
-		// names in this loop have already had this config published by this publisher,
-		// so delete them from the set of names to publish for
-		//
-		// TODO: Potentially utilize the timestamp (map value) to preserve server name for re-publication if enough time has passed
-		delete(serverNamesSet, innerName)
-	}
-	return serverNamesSet
-}
-
 // The key prefix when putting ECH configs in storage. After this
 // comes the config ID.
 const echConfigsKey = "ech/configs"

modules/caddytls/tls.go

@@ -163,6 +163,7 @@ func (t *TLS) Provision(ctx caddy.Context) error {
 
 	// set up default DNS module, if any, and make sure it implements all the
 	// common libdns interfaces, since it could be used for a variety of things
+	// (do this before provisioning other modules, since they may rely on this)
 	if len(t.DNSRaw) > 0 {
 		dnsMod, err := ctx.LoadModule(t, "DNSRaw")
 		if err != nil {