modify logging to make overrides clearer in face of vagrant always streaming to stdout. Add tests for config override. Make sure that user overrides of ssh_host and ssh_port are respected.

builder/vagrant/step_ssh_config.go

@@ -41,17 +41,23 @@ func (s *StepSSHConfig) Run(ctx context.Context, state multistep.StateBag) multi
 		return multistep.ActionHalt
 	}
 
+	if config.Comm.SSHHost == "" {
 		config.Comm.SSHHost = sshConfig.Hostname
+	}
+	if config.Comm.SSHPort == 0 {
 		port, err := strconv.Atoi(sshConfig.Port)
 		if err != nil {
 			state.Put("error", err)
 			return multistep.ActionHalt
 		}
 		config.Comm.SSHPort = port
+	}
 
 	if config.Comm.SSHUsername != "" {
 		// If user has set the username within the communicator, use the
-		// auth provided there.
+		// username, password, and/or keyfile auth provided there.
+		log.Printf("Overriding SSH config from Vagrant with the username, " +
+			"password, and private key information provided to the Packer template.")
 		return multistep.ActionContinue
 	}
 	log.Printf("identity file is %s", sshConfig.IdentityFile)

builder/vagrant/step_ssh_config_test.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"testing"
 
+	"github.com/hashicorp/packer-plugin-sdk/communicator"
 	"github.com/hashicorp/packer-plugin-sdk/multistep"
 )
 
@@ -15,6 +16,83 @@ func TestStepSSHConfig_Impl(t *testing.T) {
 	}
 }
 
+func TestPrepStepSSHConfig_sshOverrides(t *testing.T) {
+	type testcase struct {
+		name              string
+		inputSSHConfig    communicator.SSH
+		expectedSSHConfig communicator.SSH
+	}
+	tcs := []testcase{
+		{
+			// defaults to overriding with the ssh config from vagrant\
+			name:           "default",
+			inputSSHConfig: communicator.SSH{},
+			expectedSSHConfig: communicator.SSH{
+				SSHHost:     "127.0.0.1",
+				SSHPort:     2222,
+				SSHUsername: "vagrant",
+				SSHPassword: "",
+			},
+		},
+		{
+			// respects SSH host and port overrides independent of credential
+			// overrides
+			name: "host_override",
+			inputSSHConfig: communicator.SSH{
+				SSHHost: "123.45.67.8",
+				SSHPort: 1234,
+			},
+			expectedSSHConfig: communicator.SSH{
+				SSHHost:     "123.45.67.8",
+				SSHPort:     1234,
+				SSHUsername: "vagrant",
+				SSHPassword: "",
+			},
+		},
+		{
+			// respects credential overrides
+			name: "credential_override",
+			inputSSHConfig: communicator.SSH{
+				SSHUsername: "megan",
+				SSHPassword: "SoSecure",
+			},
+			expectedSSHConfig: communicator.SSH{
+				SSHHost:     "127.0.0.1",
+				SSHPort:     2222,
+				SSHUsername: "megan",
+				SSHPassword: "SoSecure",
+			},
+		},
+	}
+	for _, tc := range tcs {
+		driver := &MockVagrantDriver{}
+		config := &Config{
+			Comm: communicator.Config{
+				SSH: tc.inputSSHConfig,
+			},
+		}
+		state := new(multistep.BasicStateBag)
+		state.Put("driver", driver)
+		state.Put("config", config)
+
+		step := StepSSHConfig{}
+		_ = step.Run(context.Background(), state)
+
+		if config.Comm.SSHHost != tc.expectedSSHConfig.SSHHost {
+			t.Fatalf("unexpected sshconfig host: name: %s, recieved %s", tc.name, config.Comm.SSHHost)
+		}
+		if config.Comm.SSHPort != tc.expectedSSHConfig.SSHPort {
+			t.Fatalf("unexpected sshconfig port: name: %s, recieved %d", tc.name, config.Comm.SSHPort)
+		}
+		if config.Comm.SSHUsername != tc.expectedSSHConfig.SSHUsername {
+			t.Fatalf("unexpected sshconfig SSHUsername: name: %s, recieved %s", tc.name, config.Comm.SSHUsername)
+		}
+		if config.Comm.SSHPassword != tc.expectedSSHConfig.SSHPassword {
+			t.Fatalf("unexpected sshconfig SSHUsername: name: %s, recieved %s", tc.name, config.Comm.SSHPassword)
+		}
+	}
+}
+
 func TestPrepStepSSHConfig_GlobalID(t *testing.T) {
 	driver := &MockVagrantDriver{}
 	config := &Config{}