Log how many things were loaded for each domain

This patch makes chasquid log how many users, aliases and DKIM keys were
loaded for each domain.

This makes it easier to confirm changes, and troubleshoot problems
related to these per-domain configuration files.

internal/aliases/aliases.go

@@ -347,7 +347,7 @@ func (v *Resolver) AddDomain(domain string) {
 // AddAliasesFile to the resolver. The file will be parsed, and an error
 // returned if it does not parse correctly.  Note that the file not existing
 // does NOT result in an error.
-func (v *Resolver) AddAliasesFile(domain, path string) error {
+func (v *Resolver) AddAliasesFile(domain, path string) (int, error) {
 	// We unconditionally add the domain and file on our list.
 	// Even if the file does not exist now, it may later. This makes it be
 	// consider when doing Reload.
@@ -360,10 +360,10 @@ func (v *Resolver) AddAliasesFile(domain, path string) error {
 
 	aliases, err := v.parseFile(domain, path)
 	if os.IsNotExist(err) {
-		return nil
+		return 0, nil
 	}
 	if err != nil {
-		return err
+		return 0, err
 	}
 
 	// Add the aliases to the resolver, overriding any previous values.
@@ -373,7 +373,7 @@ func (v *Resolver) AddAliasesFile(domain, path string) error {
 	}
 	v.mu.Unlock()
 
-	return nil
+	return len(aliases), nil
 }
 
 // AddAliasForTesting adds an alias to the resolver, for testing purposes.

internal/aliases/aliases_test.go

@@ -437,7 +437,7 @@ func TestAddFile(t *testing.T) {
 		defer os.Remove(fname)
 
 		resolver := NewResolver(allUsersExist)
-		err := resolver.AddAliasesFile("dom", fname)
+		_, err := resolver.AddAliasesFile("dom", fname)
 		if err != nil {
 			t.Fatalf("error adding file: %v", err)
 		}
@@ -491,11 +491,15 @@ func TestRichFile(t *testing.T) {
 	resolver := NewResolver(allUsersExist)
 	resolver.DropChars = "."
 	resolver.SuffixSep = "+"
-	err := resolver.AddAliasesFile("dom", fname)
+	n, err := resolver.AddAliasesFile("dom", fname)
 	if err != nil {
 		t.Fatalf("failed to add file: %v", err)
 	}
 
+	if n != 11 {
+		t.Fatalf("expected 11 aliases, got %d", n)
+	}
+
 	cases := Cases{
 		{"a@dom", []Recipient{{"b@dom", EMAIL}}, nil},
 		{"c@dom", []Recipient{{"d@e", EMAIL}, {"f@dom", EMAIL}}, nil},
@@ -539,7 +543,7 @@ func TestManyFiles(t *testing.T) {
 
 	resolver := NewResolver(allUsersExist)
 	for domain, fname := range files {
-		err := resolver.AddAliasesFile(domain, fname)
+		_, err := resolver.AddAliasesFile(domain, fname)
 		if err != nil {
 			t.Fatalf("failed to add file: %v", err)
 		}

internal/smtpsrv/server.go

@@ -133,16 +133,16 @@ func (s *Server) AddDomain(d string) {
 }
 
 // AddUserDB adds a userdb file as backend for the domain.
-func (s *Server) AddUserDB(domain, f string) error {
+func (s *Server) AddUserDB(domain, f string) (int, error) {
 	// Load the userdb, and register it unconditionally (so reload works even
 	// if there are errors right now).
 	udb, err := userdb.Load(f)
 	s.authr.Register(domain, auth.WrapNoErrorBackend(udb))
-	return err
+	return udb.Len(), err
 }
 
 // AddAliasesFile adds an aliases file for the given domain.
-func (s *Server) AddAliasesFile(domain, f string) error {
+func (s *Server) AddAliasesFile(domain, f string) (int, error) {
 	return s.aliasesR.AddAliasesFile(domain, f)
 }
 

internal/userdb/userdb.go

@@ -207,6 +207,13 @@ func (db *DB) Exists(name string) bool {
 	return present
 }
 
+// Len returns the number of users in the database.
+func (db *DB) Len() int {
+	db.mu.Lock()
+	defer db.mu.Unlock()
+	return len(db.db.Users)
+}
+
 ///////////////////////////////////////////////////////////
 // Encryption schemes
 //