Adds `qemu_agent` optional config parameter

builder/proxmox/config.go

@@ -43,6 +43,7 @@ type Config struct {
 	NICs    []nicConfig  `mapstructure:"network_adapters"`
 	Disks   []diskConfig `mapstructure:"disks"`
 	ISOFile string       `mapstructure:"iso_file"`
+	Agent   string       `mapstructure:"qemu_agent"`
 
 	TemplateName        string `mapstructure:"template_name"`
 	TemplateDescription string `mapstructure:"template_description"`
@@ -149,6 +150,11 @@ func NewConfig(raws ...interface{}) (*Config, []string, error) {
 			c.Disks[idx].CacheMode = "none"
 		}
 	}
+	// Valid values: 0 - no agent, 1 - with agent; default is 1
+	if c.Agent != "0" && c.Agent != "1" {
+		log.Printf("Agent '%s' is not valid, using default: 1", c.Agent)
+		c.Agent = "1"
+	}
 
 	errs = packer.MultiErrorAppend(errs, c.Comm.Prepare(&c.ctx)...)
 	errs = packer.MultiErrorAppend(errs, c.BootConfig.Prepare(&c.ctx)...)

builder/proxmox/config_test.go

@@ -93,6 +93,7 @@ func TestBasicExampleFromDocsIsValid(t *testing.T) {
 	// OS not set, using default 'other'
 	// NIC 0 model not set, using default 'e1000'
 	// Disk 0 cache mode not set, using default 'none'
+	// Agent not set, default is 1
 
 	if b.config.Memory != 512 {
 		t.Errorf("Expected Memory to be 512, got %d", b.config.Memory)
@@ -112,4 +113,7 @@ func TestBasicExampleFromDocsIsValid(t *testing.T) {
 	if b.config.Disks[0].CacheMode != "none" {
 		t.Errorf("Expected disk cache mode to be 'none', got %s", b.config.Disks[0].CacheMode)
 	}
+	if b.config.Agent != "1" {
+		t.Errorf("Expected Agent to be 1, got %s", b.config.Agent)
+	}
 }

builder/proxmox/step_start_vm.go

@@ -24,7 +24,7 @@ func (s *stepStartVM) Run(ctx context.Context, state multistep.StateBag) multist
 	ui.Say("Creating VM")
 	config := proxmox.ConfigQemu{
 		Name:         c.VMName,
-		Agent:        "1",
+		Agent:        c.Agent,
 		Description:  "Packer ephemeral build VM",
 		Memory:       c.Memory,
 		QemuCores:    c.Cores,

website/source/docs/builders/proxmox.html.md

@@ -146,6 +146,10 @@ builder.
 -   `unmount_iso` (bool) - If true, remove the mounted ISO from the template
     after finishing. Defaults to `false`.
 
+-   `qemu_agent` (string) - Enables (`1`) or disables (`0`) the QEMU Agent option 
+    for this VM. When disabled, then Packer can't determine the guest's IP, 
+    and `ssh_host` should be used. When enabled, then `qemu-guest-agent`
+    must be installed on the guest OS. Defaults to `1`.
 
 ## Example: Fedora with kickstart