Let Pimox generate worker NIC MACs by default

README.md

@@ -734,6 +734,9 @@ qemu-guest-agent. Static mode uses
 `LAB_PIMOX_WORKER_STATIC_IPS="192.168.100.66 192.168.100.67 192.168.100.76"`,
 `LAB_PIMOX_WORKER_GATEWAY=192.168.100.1`, and
 `LAB_PIMOX_WORKER_DNS_SERVERS="192.168.100.89 1.1.1.1"`.
+Worker NIC MAC addresses are also auto-generated by Pimox by default. Set
+`LAB_PIMOX_WORKER_MAC_MODE=deterministic` only when you explicitly need stable
+MAC addresses derived from VM IDs.
 Worker creation fails faster than template creation: static guest-network
 configuration waits up to `LAB_PIMOX_GUEST_AGENT_CONFIG_TIMEOUT_SECONDS=120`,
 worker IP/SSH readiness waits up to `LAB_PIMOX_WORKER_WAIT_TIMEOUT_SECONDS=600`,

README.md.tmpl

@@ -734,6 +734,9 @@ qemu-guest-agent. Static mode uses
 `LAB_PIMOX_WORKER_STATIC_IPS="192.168.100.66 192.168.100.67 192.168.100.76"`,
 `LAB_PIMOX_WORKER_GATEWAY=192.168.100.1`, and
 `LAB_PIMOX_WORKER_DNS_SERVERS="192.168.100.89 1.1.1.1"`.
+Worker NIC MAC addresses are also auto-generated by Pimox by default. Set
+`LAB_PIMOX_WORKER_MAC_MODE=deterministic` only when you explicitly need stable
+MAC addresses derived from VM IDs.
 Worker creation fails faster than template creation: static guest-network
 configuration waits up to `LAB_PIMOX_GUEST_AGENT_CONFIG_TIMEOUT_SECONDS=120`,
 worker IP/SSH readiness waits up to `LAB_PIMOX_WORKER_WAIT_TIMEOUT_SECONDS=600`,

bootstrap/provisioning/README.md

@@ -148,6 +148,9 @@ reservations are not available: set `LAB_PIMOX_WORKER_NETWORK_MODE=static`,
 `LAB_PIMOX_WORKER_STATIC_IPS="192.168.100.66 192.168.100.67 192.168.100.76"`,
 `LAB_PIMOX_WORKER_GATEWAY=192.168.100.1`, `LAB_PIMOX_WORKER_INTERFACE=enp0s18`,
 and `LAB_PIMOX_WORKER_DNS_SERVERS="192.168.100.89 1.1.1.1"`.
+Worker NIC MAC addresses are auto-generated by Pimox by default. Set
+`LAB_PIMOX_WORKER_MAC_MODE=deterministic` only when VMID-derived MAC addresses
+are required.
 Worker clone failures are intentionally faster than template build failures:
 `LAB_PIMOX_GUEST_AGENT_CONFIG_TIMEOUT_SECONDS=120`,
 `LAB_PIMOX_WORKER_WAIT_TIMEOUT_SECONDS=600`, and

docs/jeannie.1.md

@@ -547,6 +547,10 @@ state.
 : Worker guest networking mode. Defaults to `dhcp`. Set to `static` only when
 Jeannie should configure guest static IPs through qemu-guest-agent.
 
+`LAB_PIMOX_WORKER_MAC_MODE`
+: Worker NIC MAC mode. Defaults to `auto`, letting Pimox generate the MAC. Set
+to `deterministic` to derive MAC addresses from VM IDs.
+
 `LAB_PIMOX_WORKER_REQUIRE_LAN_PROBE`
 : Require the worker guest to ping the LAN gateway and probe host after static
 IP assignment. Defaults to `true`.

jeannie

@@ -1212,6 +1212,27 @@ pimox_worker_static_ip() {
     return 1
 }
 
+pimox_worker_net0_config() {
+    local vmid="$1"
+    local bridge="$2"
+    local mac_mode="${LAB_PIMOX_WORKER_MAC_MODE:-auto}"
+    local mac
+
+    case "${mac_mode}" in
+        auto)
+            printf 'virtio,bridge=%s\n' "${bridge}"
+            ;;
+        deterministic)
+            mac="$(pimox_generated_mac "${vmid}")"
+            printf 'virtio=%s,bridge=%s\n' "${mac}" "${bridge}"
+            ;;
+        *)
+            echo "LAB_PIMOX_WORKER_MAC_MODE must be 'auto' or 'deterministic'." >&2
+            return 1
+            ;;
+    esac
+}
+
 validate_ipv4_cidr_or_host() {
     local value="$1"
 
@@ -1434,7 +1455,7 @@ ensure_pimox_worker_node() {
     local worker_key
     local worker_name
     local node_name
-    local mac
+    local net0_config
     local guest_ip
     local static_ip
 
@@ -1443,7 +1464,9 @@ ensure_pimox_worker_node() {
     worker_key="${worker_key_prefix}${padded}"
     worker_name="${worker_name_prefix}-${padded}"
     node_name="${worker_node_prefix}-${padded}"
-    mac="$(pimox_generated_mac "${vmid}")"
+    if ! net0_config="$(pimox_worker_net0_config "${vmid}" "${bridge}")"; then
+        exit 1
+    fi
 
     if pimox_ssh "${pimox_host}" "${pimox_user}" "${pimox_key}" "sudo '${qm_bin}' status '${vmid}' >/dev/null 2>&1"; then
         if pimox_ssh "${pimox_host}" "${pimox_user}" "${pimox_key}" "sudo '${qm_bin}' config '${vmid}' | grep -q '^template: 1$'"; then
@@ -1522,7 +1545,7 @@ if [ -n '${worker_cpu_affinity}' ]; then
     esac
   }
 fi
-sudo '${qm_bin}' set '${vmid}' --net0 'virtio=${mac},bridge=${bridge}'
+sudo '${qm_bin}' set '${vmid}' --net0 '${net0_config}'
 sudo '${qm_bin}' set '${vmid}' --boot 'order=scsi0;net0'
 sudo '${qm_bin}' set '${vmid}' --onboot 1
 sudo '${qm_bin}' start '${vmid}'"

tests/jeannie-unit

@@ -336,6 +336,14 @@ test_pimox_guest_exec_exitcode_parser() {
     assert_command_failure_contains "pimox guest exec rejects invalid JSON" "" pimox_guest_exec_exitcode 'not json'
 }
 
+test_pimox_worker_net0_config_defaults_to_auto_mac() {
+    unset LAB_PIMOX_WORKER_MAC_MODE
+    assert_eq "pimox worker net0 defaults to auto MAC" "virtio,bridge=vmbr0" "$(pimox_worker_net0_config 9010 vmbr0)"
+    LAB_PIMOX_WORKER_MAC_MODE=deterministic
+    assert_eq "pimox worker net0 deterministic MAC opt-in" "virtio=02:68:10:00:23:32,bridge=vmbr0" "$(pimox_worker_net0_config 9010 vmbr0)"
+    unset LAB_PIMOX_WORKER_MAC_MODE
+}
+
 test_pimox_worker_count_detects_generated_topology
 test_configured_worker_count_cannot_hide_existing_workers
 test_configured_worker_count_can_expand_target_set
@@ -350,6 +358,7 @@ test_inventory_validator_rejects_ip_drift
 test_heal_cooldown_escalates_to_diagnostics
 test_pimox_worker_static_ip_selection
 test_pimox_guest_exec_exitcode_parser
+test_pimox_worker_net0_config_defaults_to_auto_mac
 
 if ((FAILURES > 0)); then
     printf '\n%s unit test(s) failed.\n' "${FAILURES}" >&2