removed explicit "end" functions and turned them into functions returned by setup

database/base.go

@@ -15,20 +15,17 @@ import (
 	"github.com/jmoiron/sqlx"
 )
 
-// amdb is the reference to the Amsterdam database.
+// amdb is the reference to the Amsterdam database.  Returns a function to close it down.
 var amdb *sqlx.DB
 
 // SetupDb sets up the database and associated items.
-func SetupDb() error {
+func SetupDb() (func(), error) {
 	db, err := sqlx.Open(config.GlobalConfig.Database.Driver, config.GlobalConfig.Database.Dsn)
 	if err == nil {
 		amdb = db
 		// TODO: additional initialization
 	}
-	return err
-}
-
-// ClosedownDb closes down the database and associated items.
-func ClosedownDb() {
+	return func() {
 		amdb.Close()
+	}, err
 }

email/sender.go

@@ -186,7 +186,7 @@ var sendChan chan *amMessage
 var doneChan chan bool
 
 // SetupMailSender starts the mail-sending goroutine.
-func SetupMailSender() {
+func SetupMailSender() func() {
 	// Initialize mail host and authentication.
 	mailHost = fmt.Sprintf("%s:%d", config.GlobalConfig.Email.Host, config.GlobalConfig.Email.Port)
 	switch config.GlobalConfig.Email.AuthType {
@@ -211,10 +211,8 @@ func SetupMailSender() {
 	sendChan = make(chan *amMessage, 16)
 	doneChan = make(chan bool)
 	go senderLoop(sendChan, doneChan)
-}
-
-// EndMailServer shuts down the mail-sending goroutine.
-func EndMailServer() {
+	return func() {
 		close(sendChan) // will break the loop in senderLoop
 		<-doneChan      // wait for routine to complete
+	}
 }

main.go

@@ -56,13 +56,13 @@ func setupEcho() *echo.Echo {
 func main() {
 	// Configure the system.
 	config.SetupConfig()
-	err := database.SetupDb()
+	closer, err := database.SetupDb()
 	if err != nil {
 		panic(fmt.Sprintf("Database open failure: %v", err))
 	}
-	defer database.ClosedownDb()
-	email.SetupMailSender()
-	defer email.EndMailServer()
+	defer closer()
+	closer = email.SetupMailSender()
+	defer closer()
 	ui.SetupTemplates()
 	ui.SetupSessionManager()
 	ui.SetupLeftMenus()