Validate host and network when looking for network

builder/vsphere/clone/step_clone.go

@@ -21,7 +21,8 @@ type CloneConfig struct {
 	DiskSize int64 `mapstructure:"disk_size"`
 	// Create VM as a linked clone from latest snapshot. Defaults to `false`.
 	LinkedClone bool `mapstructure:"linked_clone"`
-	// Set network VM will be connected to.
+	// Set the network in which the VM will be connected to. If no network is specified, `host`
+	// must be specified to allow Packer to look for the available network.
 	Network string `mapstructure:"network"`
 	// VM notes.
 	Notes string `mapstructure:"notes"`

builder/vsphere/driver/vm.go

@@ -619,30 +619,10 @@ func addNetwork(d *Driver, devices object.VirtualDeviceList, config *CreateConfi
 		return nil, errors.New("no network adapters have been defined")
 	}
 
-	var network object.NetworkReference
 	for _, nic := range config.NICs {
-		if nic.Network == "" {
-			h, err := d.FindHost(config.Host)
-			if err != nil {
-				return nil, err
-			}
-
-			i, err := h.Info("network")
-			if err != nil {
-				return nil, err
-			}
-
-			if len(i.Network) > 1 {
-				return nil, fmt.Errorf("Host has multiple networks. Specify it explicitly")
-			}
-
-			network = object.NewNetwork(d.client.Client, i.Network[0])
-		} else {
-			var err error
-			network, err = d.finder.Network(d.ctx, nic.Network)
-			if err != nil {
-				return nil, err
-			}
+		network, err := findNetwork(nic.Network, config.Host, d)
+		if err != nil {
+			return nil, err
 		}
 
 		backing, err := network.EthernetCardBackingInfo(d.ctx)
@@ -667,6 +647,37 @@ func addNetwork(d *Driver, devices object.VirtualDeviceList, config *CreateConfi
 	return devices, nil
 }
 
+func findNetwork(network string, host string, d *Driver) (object.NetworkReference, error) {
+	if network != "" {
+		var err error
+		network, err := d.finder.Network(d.ctx, network)
+		if err != nil {
+			return nil, err
+		}
+		return network, nil
+	}
+
+	if host != "" {
+		h, err := d.FindHost(host)
+		if err != nil {
+			return nil, err
+		}
+
+		i, err := h.Info("network")
+		if err != nil {
+			return nil, err
+		}
+
+		if len(i.Network) > 1 {
+			return nil, fmt.Errorf("Host has multiple networks. Specify it explicitly")
+		}
+
+		return object.NewNetwork(d.client.Client, i.Network[0]), nil
+	}
+
+	return nil, fmt.Errorf("Couldn't find network; 'host' and 'network' not specified. At least one of the two must be specified.")
+}
+
 func newVGPUProfile(vGPUProfile string) types.VirtualPCIPassthrough {
 	return types.VirtualPCIPassthrough{
 		VirtualDevice: types.VirtualDevice{

builder/vsphere/iso/step_create.go

@@ -31,7 +31,8 @@ import (
 //   ],
 // ```
 type NIC struct {
-	// Set network VM will be connected to.
+	// Set the network in which the VM will be connected to. If no network is specified, `host`
+	// must be specified to allow Packer to look for the available network.
 	Network string `mapstructure:"network"`
 	// Set VM network card type. Example `vmxnet3`.
 	NetworkCard string `mapstructure:"network_card" required:"true"`

website/pages/partials/builder/vsphere/clone/CloneConfig-not-required.mdx

@@ -6,7 +6,8 @@
 
 -   `linked_clone` (bool) - Create VM as a linked clone from latest snapshot. Defaults to `false`.
 
--   `network` (string) - Set network VM will be connected to.
+-   `network` (string) - Set the network in which the VM will be connected to. If no network is specified, `host`
+    must be specified to allow Packer to look for the available network.
 
 -   `notes` (string) - VM notes.
 

website/pages/partials/builder/vsphere/iso/NIC-not-required.mdx

@@ -1,6 +1,7 @@
 <!-- Code generated from the comments of the NIC struct in builder/vsphere/iso/step_create.go; DO NOT EDIT MANUALLY -->
 
--   `network` (string) - Set network VM will be connected to.
+-   `network` (string) - Set the network in which the VM will be connected to. If no network is specified, `host`
+    must be specified to allow Packer to look for the available network.
 
 -   `mac_address` (string) - Set network card MAC address