feat(GODT-2538): implement smart picking of default IMAP/SMTP ports

tests/bdd_test.go

@@ -107,7 +107,10 @@ func TestFeatures(testingT *testing.T) {
 			ctx.Step(`^the header in the "([^"]*)" request to "([^"]*)" has "([^"]*)" set to "([^"]*)"$`, s.theHeaderInTheRequestToHasSetTo)
 			ctx.Step(`^the body in the "([^"]*)" request to "([^"]*)" is:$`, s.theBodyInTheRequestToIs)
 			ctx.Step(`^the API requires bridge version at least "([^"]*)"$`, s.theAPIRequiresBridgeVersion)
-
+			ctx.Step(`^the network port (\d+) is busy$`, s.networkPortIsBusy)
+			ctx.Step(`^the network port range (\d+)-(\d+) is busy$`, s.networkPortRangeIsBusy)
+			ctx.Step(`^bridge IMAP port is (\d+)`, s.bridgeIMAPPortIs)
+			ctx.Step(`^bridge SMTP port is (\d+)`, s.bridgeSMTPPortIs)
 			// ==== SETUP ====
 			ctx.Step(`^there exists an account with username "([^"]*)" and password "([^"]*)"$`, s.thereExistsAnAccountWithUsernameAndPassword)
 			ctx.Step(`^there exists a disabled account with username "([^"]*)" and password "([^"]*)"$`, s.thereExistsAnAccountWithUsernameAndPasswordWithDisablePrimary)

tests/bridge_test.go

@@ -21,7 +21,9 @@ import (
 	"context"
 	"errors"
 	"fmt"
+	"net"
 	"os"
+	"strconv"
 	"time"
 
 	"github.com/Masterminds/semver/v3"
@@ -307,3 +309,37 @@ func (s *scenario) theUserHidesAllMail() error {
 func (s *scenario) theUserShowsAllMail() error {
 	return s.t.bridge.SetShowAllMail(true)
 }
+
+func (s *scenario) networkPortIsBusy(port int) {
+	if listener, err := net.Listen("tcp", "127.0.0.1:"+strconv.Itoa(port)); err == nil { // we ignore errors. Most likely port is already busy.
+		s.t.dummyListeners = append(s.t.dummyListeners, listener)
+	}
+}
+
+func (s *scenario) networkPortRangeIsBusy(startPort, endPort int) {
+	if startPort > endPort {
+		startPort, endPort = endPort, startPort
+	}
+
+	for port := startPort; port <= endPort; port++ {
+		s.networkPortIsBusy(port)
+	}
+}
+
+func (s *scenario) bridgeIMAPPortIs(expectedPort int) error {
+	actualPort := s.t.bridge.GetIMAPPort()
+	if actualPort != expectedPort {
+		return fmt.Errorf("expected IMAP port to be %v but got %v", expectedPort, actualPort)
+	}
+
+	return nil
+}
+
+func (s *scenario) bridgeSMTPPortIs(expectedPort int) error {
+	actualPort := s.t.bridge.GetSMTPPort()
+	if actualPort != expectedPort {
+		return fmt.Errorf("expected SMTP port to be %v but got %v", expectedPort, actualPort)
+	}
+
+	return nil
+}

tests/ctx_test.go

@@ -20,6 +20,7 @@ package tests
 import (
 	"context"
 	"fmt"
+	"net"
 	"net/smtp"
 	"net/url"
 	"regexp"
@@ -160,6 +161,9 @@ type testCtx struct {
 	// errors holds test-related errors encountered while running test steps.
 	errors     [][]error
 	errorsLock sync.RWMutex
+
+	// This slice contains the dummy listeners that are intended to block network ports.
+	dummyListeners []net.Listener
 }
 
 type imapClient struct {
@@ -437,6 +441,12 @@ func (t *testCtx) close(ctx context.Context) {
 		}
 	}
 
+	for _, listener := range t.dummyListeners {
+		if err := listener.Close(); err != nil {
+			logrus.WithError(err).Errorf("Failed to close dummy listener %v", listener.Addr())
+		}
+	}
+
 	t.api.Close()
 	t.events.close()
 	t.reporter.close()

tests/features/bridge/default_ports.feature

@@ -0,0 +1,24 @@
+Feature: Bridge picks default ports wisely
+
+  Scenario: bridge picks ports for IMAP and SMTP using default values.
+    When bridge starts
+    Then bridge IMAP port is 1143
+    Then bridge SMTP port is 1025
+
+  Scenario: bridge picks ports for IMAP wisely when default port is busy.
+    When the network port 1143 is busy
+    And bridge starts
+    Then bridge IMAP port is 1144
+    Then bridge SMTP port is 1025
+
+  Scenario: bridge picks ports for SMTP wisely when default port is busy.
+    When the network port range 1025-1030 is busy
+    And bridge starts
+    Then bridge IMAP port is 1143
+    Then bridge SMTP port is 1031
+
+  Scenario: bridge picks ports for IMAP SMTP wisely when default ports are busy.
+    When the network port range 1025-1200 is busy
+    And bridge starts
+    Then bridge IMAP port is 1201
+    Then bridge SMTP port is 1202