miscellaneous qemu cleanup. Fix generator strings; generate code

fix diskimage logic
linting
fix tests

builder/qemu/builder.go

@@ -1,6 +1,3 @@
-//go:generate struct-markdown
-//go:generate mapstructure-to-hcl2 -type Config
-
 package qemu
 
 import (

builder/qemu/config.go

@@ -1,3 +1,6 @@
+//go:generate struct-markdown
+//go:generate mapstructure-to-hcl2 -type Config
+
 package qemu
 
 import (

builder/qemu/config_test.go

@@ -519,9 +519,15 @@ func TestBuilderPrepare_SSHPrivateKey(t *testing.T) {
 	}
 
 	// Test good contents
-	tf.Seek(0, 0)
-	tf.Truncate(0)
-	tf.Write([]byte(testPem))
+	if _, err := tf.Seek(0, 0); err != nil {
+		t.Fatalf("errorf getting key")
+	}
+	if err := tf.Truncate(0); err != nil {
+		t.Fatalf("errorf getting key")
+	}
+	if _, err := tf.Write([]byte(testPem)); err != nil {
+		t.Fatalf("errorf getting key")
+	}
 	config["ssh_private_key_file"] = tf.Name()
 	c = Config{}
 	warns, err = c.Prepare(config)

builder/qemu/step_run.go

@@ -35,7 +35,7 @@ func (s *stepRun) Run(ctx context.Context, state multistep.StateBag) multistep.S
 	// installation CD or a pre-baked image
 	bootDrive := "once=d"
 	message := "Starting VM, booting from CD-ROM"
-	if !s.DiskImage {
+	if s.DiskImage {
 		bootDrive = "c"
 		message = "Starting VM, booting disk image"
 	}

builder/qemu/step_run_test.go

@@ -76,9 +76,11 @@ func Test_CDFilesPath(t *testing.T) {
 		"-machine", "type=,accel=",
 		"-device", ",netdev=user.0",
 		"-drive", "file=/path/to/test.iso,index=0,media=cdrom",
-		"-drive", "file=fake_cd_path.iso,index=1,media=cdrom ",
+		"-drive", "file=fake_cd_path.iso,index=1,media=cdrom",
 	}
 
+	assert.ElementsMatch(t, args, expected, fmt.Sprintf("unexpected generated args: %#v", args))
+
 	// cd_path is set and DiskImage is true
 	config := &Config{
 		DiskImage:     true,

builder/qemu/step_wait_guest_address.go

@@ -21,15 +21,15 @@ import (
 type stepWaitGuestAddress struct {
 	CommunicatorType string
 	NetBridge        string
-	timeout          time.Duration
+
+	timeout time.Duration
 }
 
 func (s *stepWaitGuestAddress) Run(ctx context.Context, state multistep.StateBag) multistep.StepAction {
-	config := state.Get("config").(*Config)
 	ui := state.Get("ui").(packer.Ui)
 
 	if s.CommunicatorType == "none" {
-		ui.Message("Not using a communicator -- skipping StepWaitGuestAddress")
+		ui.Message("No communicator is configured -- skipping StepWaitGuestAddress")
 		return multistep.ActionContinue
 	}
 	if s.NetBridge == "" {
@@ -41,9 +41,9 @@ func (s *stepWaitGuestAddress) Run(ctx context.Context, state multistep.StateBag
 	ctx, cancel := context.WithTimeout(ctx, s.timeout)
 	defer cancel()
 
-	ui.Say(fmt.Sprintf("Waiting for the guest address to become available in the %s network bridge...", config.NetBridge))
+	ui.Say(fmt.Sprintf("Waiting for the guest address to become available in the %s network bridge...", s.NetBridge))
 	for {
-		guestAddress := getGuestAddress(qmpMonitor, config.NetBridge, "user.0")
+		guestAddress := getGuestAddress(qmpMonitor, s.NetBridge, "user.0")
 		if guestAddress != "" {
 			log.Printf("Found guest address %s", guestAddress)
 			state.Put("guestAddress", guestAddress)

website/pages/partials/builder/qemu/Config-not-required.mdx

@@ -1,4 +1,4 @@
-<!-- Code generated from the comments of the Config struct in builder/qemu/builder.go; DO NOT EDIT MANUALLY -->
+<!-- Code generated from the comments of the Config struct in builder/qemu/config.go; DO NOT EDIT MANUALLY -->
 
 - `iso_skip_cache` (bool) - Use iso from provided url. Qemu must support
   curl block device. This defaults to `false`.