Remove default route for ironic-boot device on control nodes (#2637)

The subnet has an external gateway for connectivity of instances
deployed in it.
The resulting default route received via DHCP on control nodes breaks
their external connectivity and is therefore removed by a `dhclient` hook.

Signed-off-by: Jan Horstmann <[email protected]>

Author: janhorstmann

environments/custom/playbook-baremetal-bootstrap.yml

@@ -126,6 +126,23 @@
         mode: 0664
       notify: Restart ironic-interface.service
 
+    # NOTE: The subnet has a default gateway which is used for all nodes deployed in it
+    # It may break connectivity on control nodes though and is therefore removed
+    - name: Create ironic dhclient hook
+      become: true
+      ansible.builtin.copy:
+        content: |
+          #!/bin/bash
+          if [ "${interface}" = "{{ ironic_network_interface }}" ]; then
+          case "${reason}" in BOUND|RENEW|REBIND|REBOOT)
+                      ip route delete default via {{ public_subnet.subnet.gateway_ip }} dev {{ ironic_network_interface }}
+                 ;;
+                 esac
+          fi
+        dest: /etc/dhcp/dhclient-exit-hooks.d/ironic-boot-delete-default-route
+        mode: 0755
+      notify: Restart ironic-interface.service
+
     - name: Create ironic-interface service
       become: True
       ansible.builtin.template: