module: Revise how inline definition arguments are handled

Stop using weird hacks and just pass them to the module, they are
assumed to be aware of inline definition logic anyway.

auth/external/externalauth.go

@@ -23,13 +23,17 @@ type ExternalAuth struct {
 	Log log.Logger
 }
 
-func NewExternalAuth(modName, instName string, _ []string) (module.Module, error) {
+func NewExternalAuth(modName, instName string, _, inlineArgs []string) (module.Module, error) {
 	ea := &ExternalAuth{
 		modName:  modName,
 		instName: instName,
 		Log:      log.Logger{Name: modName},
 	}
 
+	if len(inlineArgs) != 0 {
+		return nil, errors.New("external: inline arguments are not used")
+	}
+
 	return ea, nil
 }
 

auth/pam/module.go

@@ -20,7 +20,10 @@ type Auth struct {
 	Log log.Logger
 }
 
-func New(modName, instName string, _ []string) (module.Module, error) {
+func New(modName, instName string, _, inlineArgs []string) (module.Module, error) {
+	if len(inlineArgs) != 0 {
+		return nil, errors.New("pam: inline arguments are not used")
+	}
 	return &Auth{
 		instName: instName,
 		Log:      log.Logger{Name: modName},

auth/shadow/module.go

@@ -3,6 +3,7 @@
 package shadow
 
 import (
+	"errors"
 	"fmt"
 	"os"
 	"path/filepath"
@@ -21,7 +22,10 @@ type Auth struct {
 	Log log.Logger
 }
 
-func New(modName, instName string, _ []string) (module.Module, error) {
+func New(modName, instName string, _, inlineArgs []string) (module.Module, error) {
+	if len(inlineArgs) != 0 {
+		return nil, errors.New("shadow: inline arguments are not used")
+	}
 	return &Auth{
 		instName: instName,
 		Log:      log.Logger{Name: modName},

check/dkim/dkim.go

@@ -3,6 +3,7 @@ package dkim
 import (
 	"bytes"
 	"context"
+	"errors"
 	"io"
 
 	"github.com/emersion/go-message/textproto"
@@ -25,7 +26,10 @@ type Check struct {
 	noSigAction     check.FailAction
 }
 
-func New(_, instName string, _ []string) (module.Module, error) {
+func New(_, instName string, _, inlineArgs []string) (module.Module, error) {
+	if len(inlineArgs) != 0 {
+		return nil, errors.New("verify_dkim: inline arguments are not used")
+	}
 	return &Check{
 		instName: instName,
 		log:      log.Logger{Name: "verify_dkim"},

check/stateless_check.go

@@ -2,6 +2,7 @@ package check
 
 import (
 	"context"
+	"fmt"
 	"net"
 
 	"github.com/emersion/go-message/textproto"
@@ -155,7 +156,10 @@ func (c *statelessCheck) InstanceName() string {
 // populate RejectErr field of the result object with the relevant error description. Fields ScoreAdjust and
 // Quarantine will be ignored.
 func RegisterStatelessCheck(name string, defaultFailAction FailAction, connCheck FuncConnCheck, senderCheck FuncSenderCheck, rcptCheck FuncRcptCheck, bodyCheck FuncBodyCheck) {
-	module.Register(name, func(modName, instName string, aliases []string) (module.Module, error) {
+	module.Register(name, func(modName, instName string, aliases, inlineArgs []string) (module.Module, error) {
+		if len(inlineArgs) != 0 {
+			return nil, fmt.Errorf("%s: inline arguments are not used", modName)
+		}
 		return &statelessCheck{
 			modName:  modName,
 			instName: instName,

config/module/modconfig.go

@@ -18,15 +18,15 @@ import (
 )
 
 // createInlineModule is a helper function for config matchers that can create inline modules.
-func createInlineModule(modName, instName string, aliases []string) (module.Module, error) {
+func createInlineModule(modName string, args []string) (module.Module, error) {
 	newMod := module.Get(modName)
 	if newMod == nil {
 		return nil, fmt.Errorf("unknown module: %s", modName)
 	}
 
-	log.Debugln("module create", modName, instName, "(inline)")
+	log.Debugln("module create", modName, args, "(inline)")
 
-	return newMod(modName, instName, aliases)
+	return newMod(modName, "", nil, args)
 }
 
 // initInlineModule constructs "faked" config tree and passes it to module
@@ -69,16 +69,7 @@ func ModuleFromNode(args []string, inlineCfg *config.Node, globals map[string]in
 	var modObj module.Module
 	var err error
 	if inlineCfg.Children != nil || len(args) > 1 {
-		modName := args[0]
-
-		modAliases := args[1:]
-		instName := ""
-		if len(args) >= 2 {
-			modAliases = args[2:]
-			instName = args[1]
-		}
-
-		modObj, err = createInlineModule(modName, instName, modAliases)
+		modObj, err = createInlineModule(args[0], args[1:])
 	} else {
 		if len(args) != 1 {
 			return config.NodeErr(inlineCfg, "exactly one argument is to use existing config block")

endpoint/imap/imap.go

@@ -41,7 +41,10 @@ type Endpoint struct {
 	Log log.Logger
 }
 
-func New(_, instName string, aliases []string) (module.Module, error) {
+func New(_, instName string, aliases, inlineArgs []string) (module.Module, error) {
+	if len(inlineArgs) != 0 {
+		return nil, errors.New("imap: inline arguments are not used")
+	}
 	endp := &Endpoint{
 		name:    instName,
 		aliases: aliases,

endpoint/smtp/smtp.go

@@ -239,7 +239,10 @@ func (endp *Endpoint) InstanceName() string {
 	return endp.name
 }
 
-func New(modName, instName string, aliases []string) (module.Module, error) {
+func New(modName, instName string, aliases, inlineArgs []string) (module.Module, error) {
+	if len(inlineArgs) != 0 {
+		return nil, fmt.Errorf("%s: inline arguments are not used", modName)
+	}
 	endp := &Endpoint{
 		name:       instName,
 		aliases:    aliases,

maddy.go

@@ -69,7 +69,7 @@ func Start(cfg []config.Node) error {
 		}
 
 		log.Debugln("module create", modName, instName)
-		inst, err := factory(modName, instName, modAliases)
+		inst, err := factory(modName, instName, modAliases, nil)
 		if err != nil {
 			return err
 		}

module/module.go

@@ -50,19 +50,8 @@ type Module interface {
 //
 // Module.InstanceName() of the returned module object should return instName.
 // aliases slice contains other names that can be used to reference created
-// module instance. Here is the example of top-level declarations and the
-// corresponding arguments passed to module constructor:
+// module instance.
 //
-// modname { }
-// Arguments: "modname", "modname", nil.
-//
-// modname instname { }
-// Arguments: "modname", "instname", nil
-//
-// modname instname secondname1 secondname2 { }
-// Arguments: "modname", "instname", []string{"secondname1", "secondname2"}
-//
-// Note modules are allowed to attach additional meaning to used names.
-// For example, endpoint modules use instance name and aliases as addresses
-// to listen on.
-type FuncNewModule func(modName, instName string, aliases []string) (Module, error)
+// If module is defined inline, instName will be empty and all values
+// specified after module name in configuration will be in inlineArgs.
+type FuncNewModule func(modName, instName string, aliases, inlineArgs []string) (Module, error)

storage/sql/sql.go

@@ -144,7 +144,10 @@ func (store *Storage) InstanceName() string {
 	return store.instName
 }
 
-func New(_, instName string, _ []string) (module.Module, error) {
+func New(_, instName string, _, inlineArgs []string) (module.Module, error) {
+	if len(inlineArgs) != 0 {
+		return nil, errors.New("sql: inline arguments are not used")
+	}
 	return &Storage{
 		instName: instName,
 		Log:      log.Logger{Name: "sql"},

target/queue/queue.go

@@ -112,7 +112,10 @@ type QueueMetadata struct {
 	DSN bool
 }
 
-func NewQueue(_, instName string, _ []string) (module.Module, error) {
+func NewQueue(_, instName string, _, inlineArgs []string) (module.Module, error) {
+	if len(inlineArgs) != 0 {
+		return nil, errors.New("queue: inline arguments are not used")
+	}
 	return &Queue{
 		name:             instName,
 		initialRetryTime: 15 * time.Minute,

target/remote/remote.go

@@ -49,7 +49,10 @@ type Target struct {
 
 var _ module.DeliveryTarget = &Target{}
 
-func New(_, instName string, _ []string) (module.Module, error) {
+func New(_, instName string, _, inlineArgs []string) (module.Module, error) {
+	if len(inlineArgs) != 0 {
+		return nil, errors.New("remote: inline arguments are not used")
+	}
 	return &Target{
 		name:        instName,
 		resolver:    net.DefaultResolver,

testutils/check.go

@@ -67,7 +67,7 @@ func (cs *checkState) Close() error {
 }
 
 func init() {
-	module.Register("test_check", func(modName, instanceName string, aliases []string) (module.Module, error) {
+	module.Register("test_check", func(_, _ string, _, _ []string) (module.Module, error) {
 		return &Check{}, nil
 	})
 	module.RegisterInstance(&Check{}, nil)

testutils/modifier.go

@@ -95,7 +95,7 @@ func (ms modifierState) Close() error {
 }
 
 func init() {
-	module.Register("test_modifier", func(modName, instanceName string, aliases []string) (module.Module, error) {
+	module.Register("test_modifier", func(_, _ string, _, _ []string) (module.Module, error) {
 		return &Modifier{}, nil
 	})
 	module.RegisterInstance(&Modifier{}, nil)