caddyfile: Populate regexp matcher names by default (#6145)

* caddyfile: Populate regexp matcher names by default

* Some lint cleanup that my VSCode complained about

* Pass down matcher name through expression matcher

* Compat with #6113: fix adapt test, set both styles in replacer

4 files changed, 49 insertions, 3 deletions

diff --git a/caddyconfig/caddyfile/dispenser.go b/caddyconfig/caddyfile/dispenser.go
index 215a1641f..e36275a1c 100644
--- a/caddyconfig/caddyfile/dispenser.go
+++ b/caddyconfig/caddyfile/dispenser.go
@@ -30,6 +30,10 @@ type Dispenser struct {
 	tokens  []Token
 	cursor  int
 	nesting int
+
+	// A map of arbitrary context data that can be used
+	// to pass through some information to unmarshalers.
+	context map[string]any
 }
 
 // NewDispenser returns a Dispenser filled with the given tokens.
@@ -454,6 +458,34 @@ func (d *Dispenser) DeleteN(amount int) []Token {
 	return d.tokens
 }
 
+// SetContext sets a key-value pair in the context map.
+func (d *Dispenser) SetContext(key string, value any) {
+	if d.context == nil {
+		d.context = make(map[string]any)
+	}
+	d.context[key] = value
+}
+
+// GetContext gets the value of a key in the context map.
+func (d *Dispenser) GetContext(key string) any {
+	if d.context == nil {
+		return nil
+	}
+	return d.context[key]
+}
+
+// GetContextString gets the value of a key in the context map
+// as a string, or an empty string if the key does not exist.
+func (d *Dispenser) GetContextString(key string) string {
+	if d.context == nil {
+		return ""
+	}
+	if val, ok := d.context[key].(string); ok {
+		return val
+	}
+	return ""
+}
+
 // isNewLine determines whether the current token is on a different
 // line (higher line number) than the previous token. It handles imported
 // tokens correctly. If there isn't a previous token, it returns true.
@@ -485,3 +517,5 @@ func (d *Dispenser) isNextOnNewLine() bool {
 	next := d.tokens[d.cursor+1]
 	return isNextOnNewLine(curr, next)
 }
+
+const MatcherNameCtxKey = "matcher_name"
diff --git a/caddyconfig/httpcaddyfile/httptype.go b/caddyconfig/httpcaddyfile/httptype.go
index ab1012939..0d831403b 100644
--- a/caddyconfig/httpcaddyfile/httptype.go
+++ b/caddyconfig/httpcaddyfile/httptype.go
@@ -1397,6 +1397,14 @@ func parseMatcherDefinitions(d *caddyfile.Dispenser, matchers map[string]caddy.M
 	// given a matcher name and the tokens following it, parse
 	// the tokens as a matcher module and record it
 	makeMatcher := func(matcherName string, tokens []caddyfile.Token) error {
+		// create a new dispenser from the tokens
+		dispenser := caddyfile.NewDispenser(tokens)
+
+		// set the matcher name (without @) in the dispenser context so
+		// that matcher modules can access it to use it as their name
+		// (e.g. regexp matchers which use the name for capture groups)
+		dispenser.SetContext(caddyfile.MatcherNameCtxKey, definitionName[1:])
+
 		mod, err := caddy.GetModule("http.matchers." + matcherName)
 		if err != nil {
 			return fmt.Errorf("getting matcher module '%s': %v", matcherName, err)
@@ -1405,7 +1413,7 @@ func parseMatcherDefinitions(d *caddyfile.Dispenser, matchers map[string]caddy.M
 		if !ok {
 			return fmt.Errorf("matcher module '%s' is not a Caddyfile unmarshaler", matcherName)
 		}
-		err = unm.UnmarshalCaddyfile(caddyfile.NewDispenser(tokens))
+		err = unm.UnmarshalCaddyfile(dispenser)
 		if err != nil {
 			return err
 		}
diff --git a/caddyconfig/httpcaddyfile/serveroptions.go b/caddyconfig/httpcaddyfile/serveroptions.go
index 62902b964..18f14996c 100644
--- a/caddyconfig/httpcaddyfile/serveroptions.go
+++ b/caddyconfig/httpcaddyfile/serveroptions.go
@@ -291,7 +291,7 @@ func unmarshalCaddyfileServerOptions(d *caddyfile.Dispenser) (any, error) {
 func applyServerOptions(
 	servers map[string]*caddyhttp.Server,
 	options map[string]any,
-	warnings *[]caddyconfig.Warning,
+	_ *[]caddyconfig.Warning,
 ) error {
 	serverOpts, ok := options["servers"].([]serverOptions)
 	if !ok {
diff --git a/caddyconfig/httpcaddyfile/tlsapp.go b/caddyconfig/httpcaddyfile/tlsapp.go
index 08da3a5c7..e5d1603ed 100644
--- a/caddyconfig/httpcaddyfile/tlsapp.go
+++ b/caddyconfig/httpcaddyfile/tlsapp.go
@@ -487,7 +487,11 @@ func fillInGlobalACMEDefaults(issuer certmagic.Issuer, options map[string]any) e
 // for any other automation policies. A nil policy (and no error) will be
 // returned if there are no default/global options. However, if always is
 // true, a non-nil value will always be returned (unless there is an error).
-func newBaseAutomationPolicy(options map[string]any, warnings []caddyconfig.Warning, always bool) (*caddytls.AutomationPolicy, error) {
+func newBaseAutomationPolicy(
+	options map[string]any,
+	_ []caddyconfig.Warning,
+	always bool,
+) (*caddytls.AutomationPolicy, error) {
 	issuers, hasIssuers := options["cert_issuer"]
 	_, hasLocalCerts := options["local_certs"]
 	keyType, hasKeyType := options["key_type"]