Make DHCP inventory handling more flexible

Configure a hostsdir even when inventory_dhcp is false, so that
a deployment can use a mixed approach.

Stop creating an unused additional DNS hostsdir by default since
we disable DNS by default. While we're here, rename
disable_dnsmasq_dns -> ! dnsmasq_enable_dns for consistency.

Change-Id: If40f044a86cdde6d653bbfb441de53fb4071e390

playbooks/roles/bifrost-ironic-install/defaults/main.yml

@@ -124,7 +124,6 @@ ipa_builder_git_url: https://opendev.org/openstack/ironic-python-agent-builder
 prometheus_exporter_git_url: https://opendev.org/openstack/ironic-prometheus-exporter
 mysql_username: "root"
 mysql_password: ""
-disable_dnsmasq_dns: True
 ironic_git_folder: /opt/stack/ironic
 ironicclient_git_folder: /opt/stack/python-ironicclient
 openstacksdk_git_folder: /opt/stack/openstacksdk
@@ -164,6 +163,16 @@ dhcp_pool_start: 192.168.1.200
 dhcp_pool_end: 192.168.1.250
 dhcp_lease_time: 12h
 dhcp_static_mask: 255.255.255.0
+
+# Whether to enable DNS in dnsmasq. Will conflict with any other DNS server,
+# hence disabled by default.
+dnsmasq_enable_dns: "{{ not (dnsmasq_disable_dns | default(True) | bool) }}"
+# Directory with static DHCP hosts configuration.
+dnsmasq_dhcp_hostsdir: "/etc/dnsmasq.d/bifrost.dhcp-hosts.d"
+# Uncomment to set up directory with additional hosts for DNS. Useless without
+# dnsmasq_enable_dns set to True.
+#dnsmasq_additional_hostsdir: "/etc/dnsmasq.d/bifrost.hosts.d"
+
 # Dnsmasq default route for clients. If not defined, dnsmasq will push to clients
 # as default route the same IP of the dnsmasq server.
 # If set to false, it will disable default route creation in clients.

playbooks/roles/bifrost-ironic-install/tasks/bootstrap.yml

@@ -242,22 +242,23 @@
 - name: "Create an ESP image"
   import_tasks: create_esp.yml
 
-- name: "Setup Inventory Hosts Directory"
+- name: "Setup additional DHCP hosts directory"
   file:
-    path: "/etc/dnsmasq.d/bifrost.hosts.d"
+    path: "{{ dnsmasq_additional_hostsdir }}"
     state: directory
     owner: "root"
     group: "root"
     mode: 0755
-  when: inventory_dhcp | bool
-- name: "Setup Inventory DHCP Hosts Directory"
+  when: dnsmasq_additional_hostsdir is defined
+
+- name: "Setup inventory DHCP hosts directory"
   file:
-    path: "/etc/dnsmasq.d/bifrost.dhcp-hosts.d"
+    path: "{{ dnsmasq_dhcp_hostsdir }}"
     state: directory
     owner: "root"
     group: "root"
     mode: 0755
-  when: inventory_dhcp | bool
+
 - name: "Retrieve interface IP informations"
   set_fact:
     itf_infos: "{{ internal_interface }}"

playbooks/roles/bifrost-ironic-install/templates/dnsmasq.conf.j2

@@ -7,10 +7,10 @@
 # Listen on this specific port instead of the standard DNS port
 # (53). Setting this to zero completely disables DNS function,
 # leaving only DHCP and/or TFTP.
-{% if disable_dnsmasq_dns | bool == true %}
-port=0
-{% else %}
+{% if dnsmasq_enable_dns | bool == true %}
 port=53
+{% else %}
+port=0
 {% endif %}
 
 listen-address={{ internal_ip }}
@@ -34,9 +34,13 @@ conf-dir=/etc/dnsmasq.d
 # or if you want it to read another file, as well as /etc/hosts, use
 # this.
 #addn-hosts=/etc/banner_add_hosts
+{% if dnsmasq_additional_hostsdir is defined %}
+addn-hosts={{ dhcp_additional_hostsdir }}
+{% endif %}
+
+dhcp-hostsdir={{ dnsmasq_dhcp_hostsdir }}
+
 {% if inventory_dhcp | bool == true %}
-addn-hosts=/etc/dnsmasq.d/bifrost.hosts.d
-dhcp-hostsfile=/etc/dnsmasq.d/bifrost.dhcp-hosts.d
 dhcp-ignore=tag:!known
 {% endif %}
 

releasenotes/notes/inventory-ddf41d563a320201.yaml

@@ -0,0 +1,15 @@
+---
+features:
+  - |
+    The dynamic DHCP inventory hostsdir is now created and enabled by default,
+    even when ``inventory_dhcp`` is ``false``.
+upgrade:
+  - |
+    An additional DNS hosts directory is no longer created by default in
+    ``/etc/dnsmasq.d/bifrost.hosts.d`` when ``inventory_dhcp`` is ``true``.
+    Set the new variable ``dnsmasq_additional_hostsdir`` to keep the previous
+    behavior (you'll need ``dnsmasq_enable_dns=true`` to actually use it).
+deprecations:
+  - |
+    The parameter ``disable_dnsmasq_dns`` has been deprecated in favor of
+    the new parameter ``dnsmasq_enable_dns``.