terraform: add parameterized multi-VM deployment system

Implements Phase 1 of the OpenTofu deployment plan:
- Replace single-VM configuration with locals-based for_each pattern
- Support multiple VMs in single deployment
- Automatic DHCP vs static IP detection
- Configurable defaults with per-VM overrides
- Dynamic outputs for VM IPs and specifications

New files:
- outputs.tf: Dynamic outputs for deployed VMs
- vms.tf: VM definitions using locals.vms map

Updated files:
- variables.tf: Added default variables for VM configuration
- README.md: Comprehensive documentation and examples

Removed files:
- vm.tf: Replaced by new vms.tf (archived as vm.tf.old, then removed)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

terraform/vms.tf

@@ -0,0 +1,114 @@
+# VM Definitions
+# Define all VMs to deploy in the locals.vms map below
+# Omit fields to use defaults from variables.tf
+
+locals {
+  # Define VMs here
+  # Each VM can override defaults by specifying values
+  # Omit "ip" field for DHCP, include it for static IP
+  vms = {
+    # Example DHCP VM (uncomment to deploy):
+    # "example-dhcp-vm" = {
+    #   cpu_cores = 2
+    #   memory    = 2048
+    #   disk_size = "20G"
+    # }
+
+    # Example Static IP VM (uncomment to deploy):
+    # "example-static-vm" = {
+    #   ip        = "10.69.13.50/24"
+    #   cpu_cores = 4
+    #   memory    = 4096
+    #   disk_size = "50G"
+    # }
+
+    # Example Minimal VM using all defaults (uncomment to deploy):
+    # "minimal-vm" = {}
+  }
+
+  # Compute VM configurations with defaults applied
+  vm_configs = {
+    for name, vm in local.vms : name => {
+      target_node    = lookup(vm, "target_node", var.default_target_node)
+      template_name  = lookup(vm, "template_name", var.default_template_name)
+      cpu_cores      = lookup(vm, "cpu_cores", var.default_cpu_cores)
+      memory         = lookup(vm, "memory", var.default_memory)
+      disk_size      = lookup(vm, "disk_size", var.default_disk_size)
+      storage        = lookup(vm, "storage", var.default_storage)
+      bridge         = lookup(vm, "bridge", var.default_bridge)
+      vlan_tag       = lookup(vm, "vlan_tag", var.default_vlan_tag)
+      ssh_public_key = lookup(vm, "ssh_public_key", var.default_ssh_public_key)
+      nameservers    = lookup(vm, "nameservers", var.default_nameservers)
+      search_domain  = lookup(vm, "search_domain", var.default_search_domain)
+      # Network configuration - detect DHCP vs static
+      ip      = lookup(vm, "ip", null)
+      gateway = lookup(vm, "gateway", var.default_gateway)
+    }
+  }
+}
+
+# Deploy all VMs using for_each
+resource "proxmox_vm_qemu" "vm" {
+  for_each = local.vm_configs
+
+  name        = each.key
+  target_node = each.value.target_node
+
+  # Clone from template
+  clone      = each.value.template_name
+  full_clone = true
+
+  # Boot configuration
+  boot   = "order=virtio0"
+  scsihw = "virtio-scsi-single"
+
+  # VM settings
+  cpu {
+    cores = each.value.cpu_cores
+  }
+  memory = each.value.memory
+
+  # Network
+  network {
+    id     = 0
+    model  = "virtio"
+    bridge = each.value.bridge
+    tag    = each.value.vlan_tag
+  }
+
+  # Disk settings
+  disks {
+    virtio {
+      virtio0 {
+        disk {
+          size    = each.value.disk_size
+          storage = each.value.storage
+        }
+      }
+    }
+  }
+
+  # Start on boot
+  start_at_node_boot = true
+
+  # Agent
+  agent = 1
+
+  # Cloud-init configuration
+  ciuser       = "root"
+  sshkeys      = each.value.ssh_public_key
+  nameserver   = each.value.nameservers
+  searchdomain = each.value.search_domain
+
+  # Network configuration - DHCP or static IP
+  ipconfig0 = each.value.ip != null ? "ip=${each.value.ip},gw=${each.value.gateway}" : "ip=dhcp"
+
+  # Skip IPv6 since we don't use it
+  skip_ipv6 = true
+
+  # RNG device for better entropy
+  rng {
+    source = "/dev/urandom"
+    period = 1000
+  }
+}