config: Replace robfig with envconfig for #86

- Initial envconfig system is working, not bulletproof.
- Added sane defaults for required parameters.

pkg/server/smtp/handler.go

@@ -412,9 +412,9 @@ func (ss *Session) greet() {
 	ss.send(fmt.Sprintf("220 %v Inbucket SMTP ready", ss.server.domain))
 }
 
-// Calculate the next read or write deadline based on maxIdleSeconds
+// Calculate the next read or write deadline based on maxIdle
 func (ss *Session) nextDeadline() time.Time {
-	return time.Now().Add(time.Duration(ss.server.maxIdleSeconds) * time.Second)
+	return time.Now().Add(ss.server.maxIdle)
 }
 
 // Send requested message, store errors in Session.sendError

pkg/server/smtp/handler_test.go

@@ -361,13 +361,12 @@ func (m *mockConn) SetWriteDeadline(t time.Time) error { return nil }
 
 func setupSMTPServer(ds storage.Store) (s *Server, buf *bytes.Buffer, teardown func()) {
 	// Test Server Config
-	cfg := config.SMTPConfig{
-		IP4address:      net.IPv4(127, 0, 0, 1),
-		IP4port:         2500,
+	cfg := config.SMTP{
+		Addr:            "127.0.0.1:2500",
 		Domain:          "inbucket.local",
 		DomainNoStore:   "bitbucket.local",
 		MaxRecipients:   5,
-		MaxIdleSeconds:  5,
+		MaxIdle:         5,
 		MaxMessageBytes: 5000,
 		StoreMessages:   true,
 	}

pkg/server/smtp/listener.go

@@ -4,7 +4,6 @@ import (
 	"container/list"
 	"context"
 	"expvar"
-	"fmt"
 	"net"
 	"strings"
 	"sync"
@@ -43,7 +42,7 @@ type Server struct {
 	domain          string
 	domainNoStore   string
 	maxRecips       int
-	maxIdleSeconds  int
+	maxIdle         time.Duration
 	maxMessageBytes int
 	storeMessages   bool
 
@@ -80,17 +79,17 @@ var (
 
 // NewServer creates a new Server instance with the specificed config
 func NewServer(
-	cfg config.SMTPConfig,
+	cfg config.SMTP,
 	globalShutdown chan bool,
 	manager message.Manager,
 	apolicy *policy.Addressing,
 ) *Server {
 	return &Server{
-		host:            fmt.Sprintf("%v:%v", cfg.IP4address, cfg.IP4port),
+		host:            cfg.Addr,
 		domain:          cfg.Domain,
 		domainNoStore:   strings.ToLower(cfg.DomainNoStore),
 		maxRecips:       cfg.MaxRecipients,
-		maxIdleSeconds:  cfg.MaxIdleSeconds,
+		maxIdle:         cfg.MaxIdle,
 		maxMessageBytes: cfg.MaxMessageBytes,
 		storeMessages:   cfg.StoreMessages,
 		globalShutdown:  globalShutdown,