Use host vars files for kolla ansible inventory

Kayobe writes out several host variables to the Kolla ansible inventory
files, etc/kolla/inventory/seed and etc/kolla/inventory/overcloud. These
include ansible_host, and network interfaces such as api_interface,
ironic_dnsmasq_interface, etc.

In Ansible, these should have a higher precedence than the kolla ansible
group variables in ansible/group_vars/all.yml that set the defaults.
However, in Ansible 2.4+, if the host has the same name as a group that
it is in, the group variables now take precedence, meaning that it is
not possible to override them.

This was observed when using the kayobe-config-dev repo for testing,
where the seed host is in the seed group.

Admittedly ansible does tell you not to do this: [WARNING]:
Found both group and host with same name: localhost

The solution used here is to use a separate host_vars file for each
host. Alternatively we could enforce that hostnames and groups do not
overlap.

Change-Id: I349c8279d85a591689ac8108bce14d96889440fe
Story: 2004418
Task: 28065

ansible/roles/kolla-ansible/tasks/config.yml

@@ -1,4 +1,31 @@
 ---
+# NOTE: We're not looping over the two inventory files to avoid having the file
+# content displayed in the ansible-playbook output.
+
+- name: Check whether the legacy Kolla overcloud inventory files exist
+  stat:
+    path: "{{ item }}"
+    get_attributes: no
+    get_checksum: no
+    get_mime: no
+  register: inventory_stat
+  with_items:
+    - "{{ kolla_seed_inventory_path }}"
+    - "{{ kolla_overcloud_inventory_path }}"
+  loop_control:
+    label: "{{ item | basename }}"
+
+- name: Ensure the legacy Kolla overcloud inventory file is absent
+  file:
+    path: "{{ item.item }}"
+    state: absent
+  with_items: "{{ inventory_stat.results }}"
+  when:
+    - item.stat.exists
+    - item.stat.isreg
+  loop_control:
+    label: "{{ item.item | basename }}"
+
 - name: Ensure the Kolla Ansible configuration directories exist
   file:
     path: "{{ item }}"
@@ -9,7 +36,8 @@
   become: True
   with_items:
     - "{{ kolla_config_path }}"
-    - "{{ kolla_config_path }}/inventory"
+    - "{{ kolla_seed_inventory_path }}/host_vars"
+    - "{{ kolla_overcloud_inventory_path }}/host_vars"
     - "{{ kolla_node_custom_config_path }}"
 
 - name: Ensure the Kolla global configuration file exists
@@ -18,21 +46,42 @@
     dest: "{{ kolla_config_path }}/globals.yml"
     mode: 0640
 
-# NOTE: We're not looping over the two inventory files to avoid having the file
-# content displayed in the ansible-playbook output.
-
 - name: Ensure the Kolla seed inventory file exists
   copy:
     content: "{{ kolla_seed_inventory }}"
-    dest: "{{ kolla_config_path }}/inventory/seed"
+    dest: "{{ kolla_seed_inventory_path }}/hosts"
     mode: 0640
 
+- name: Ensure the Kolla seed host vars files exist
+  template:
+    src: host-vars.j2
+    dest: "{{ kolla_seed_inventory_path }}/host_vars/{{ host }}"
+    mode: 0640
+  with_inventory_hostnames: "seed"
+  vars:
+    host_vars: "{{ kolla_seed_inventory_pass_through_host_vars }}"
+    host_vars_map: "{{ kolla_seed_inventory_pass_through_host_vars_map }}"
+  loop_control:
+    loop_var: host
+
 - name: Ensure the Kolla overcloud inventory file exists
   copy:
     content: "{{ kolla_overcloud_inventory }}"
-    dest: "{{ kolla_config_path }}/inventory/overcloud"
+    dest: "{{ kolla_overcloud_inventory_path }}/hosts"
     mode: 0640
 
+- name: Ensure the Kolla overcloud host vars files exist
+  template:
+    src: host-vars.j2
+    dest: "{{ kolla_overcloud_inventory_path }}/host_vars/{{ host }}"
+    mode: 0640
+  with_inventory_hostnames: "{{ kolla_overcloud_top_level_groups }}"
+  vars:
+    host_vars: "{{ kolla_overcloud_inventory_pass_through_host_vars }}"
+    host_vars_map: "{{ kolla_overcloud_inventory_pass_through_host_vars_map }}"
+  loop_control:
+    loop_var: host
+
 - name: Ensure the Kolla passwords file exists
   kolla_passwords:
     src: "{{ kolla_ansible_passwords_path }}"

ansible/roles/kolla-ansible/templates/host-vars.j2

@@ -0,0 +1,7 @@
+---
+{% for hv_name in host_vars %}
+{% set host_hv=hostvars[host] %}
+{% if hv_name in host_hv %}
+{{ host_vars_map.get(hv_name, hv_name) }}: {{ host_hv[hv_name] | to_json }}
+{% endif %}
+{% endfor %}

ansible/roles/kolla-ansible/templates/overcloud-top-level.j2

@@ -4,26 +4,17 @@
 # Components define groups of services, e.g. nova or ironic.
 # Services define single containers, e.g. nova-compute or ironic-api.
 
-{% set top_level_groups = kolla_overcloud_inventory_top_level_group_map.values() |
+{% for group in kolla_overcloud_top_level_groups %}
-                          selectattr('groups', 'defined') |
-                          map(attribute='groups') |
-                          sum(start=[]) |
-                          unique |
-                          list %}
-
-{% for group in top_level_groups %}
 # Top level {{ group }} group.
 [{{ group }}]
 # These hostnames must be resolvable from your deployment host
 {% for host in groups.get(group, []) %}
-{% set host_hv=hostvars[host] %}
+{{ host }}
-{{ host }}{% for hv_name in kolla_overcloud_inventory_pass_through_host_vars %}{% if hv_name in host_hv %} {{ kolla_overcloud_inventory_pass_through_host_vars_map.get(hv_name, hv_name) }}='{{ host_hv[hv_name] | to_json }}'{% endif %}{% endfor %}
-
 {% endfor %}
 
 {% endfor %}
 [overcloud:children]
-{% for group in top_level_groups %}
+{% for group in kolla_overcloud_top_level_groups %}
 {{ group }}
 {% endfor %}
 

ansible/roles/kolla-ansible/templates/seed.j2

@@ -1,9 +1,7 @@
 # Simple inventory for bootstrapping Kolla seed node.
 [seed]
 {% for seed in groups.get('seed', []) %}
-{% set seed_hv=hostvars[seed] %}
+{{ seed }}
-{{ seed }}{% for hv_name in kolla_seed_inventory_pass_through_host_vars %}{% if hv_name in seed_hv %} {{ kolla_seed_inventory_pass_through_host_vars_map.get(hv_name, hv_name) }}='{{ seed_hv[hv_name] | to_json }}'{% endif %}{% endfor %}
-
 {% endfor %}
 
 [seed:vars]

ansible/roles/kolla-ansible/tests/main.yml

@@ -1,7 +1,5 @@
 ---
 # TODO:
-# - Check inventory file.
-# - Add hosts to inventory.
 # - Seed custom inventory
 # - Overcloud custom inventory
 #   - Group map

ansible/roles/kolla-ansible/tests/test-defaults.yml

@@ -123,7 +123,9 @@
             path: "{{ temp_path ~ '/etc/kolla/inventory/' ~ item }}"
           with_items:
             - seed
+            - seed/host_vars
             - overcloud
+            - overcloud/host_vars
           register: inventory_stat
 
         - name: Validate inventory files

ansible/roles/kolla-ansible/tests/test-extras.yml

@@ -371,7 +371,7 @@
 
         - name: Check whether inventory files exist
           stat:
-            path: "{{ temp_path ~ '/etc/kolla/inventory/' ~ item }}"
+            path: "{{ temp_path ~ '/etc/kolla/inventory/' ~ item ~ '/hosts' }}"
           with_items:
             - seed
             - overcloud
@@ -398,7 +398,7 @@
           assert:
             that: item in inventory_lines
           with_items:
-            - test-seed ansible_host='"1.2.3.4"' api_interface='"eth0"' bifrost_network_interface='"eth1"'
+            - test-seed
 
         - name: Validate overcloud inventory file contents
           vars:
@@ -406,8 +406,72 @@
           assert:
             that: item in inventory_lines
           with_items:
-            - test-controller ansible_host='"1.2.3.5"' network_interface='"eth0"' api_interface='"eth2"' storage_interface='"eth3"' cluster_interface='"eth4"' provision_interface='"eth8"' ironic_dnsmasq_interface='"eth9"' dns_interface='"eth5"' tunnel_interface='"eth10"' kolla_external_vip_interface='"eth1"' neutron_external_interface='"eth6,eth7"' neutron_bridge_name='"br0,br1"'
+            - test-controller
-            - test-compute ansible_host='"1.2.3.6"' network_interface='"eth0"' api_interface='"eth2"' storage_interface='"eth3"' tunnel_interface='"eth6"' neutron_external_interface='"eth4,eth5"' neutron_bridge_name='"br0,br1"'
+            - test-compute
+
+        - name: Check whether inventory host vars files exist
+          stat:
+            path: "{{ temp_path ~ '/etc/kolla/inventory/' ~ item }}"
+          with_items:
+            - seed/host_vars/test-seed
+            - overcloud/host_vars/test-controller
+            - overcloud/host_vars/test-compute
+          register: host_vars_stat
+
+        - name: Validate inventory host vars files
+          assert:
+            that:
+              - item.stat.exists
+              - item.stat.size > 0
+            msg: >
+              Inventory file {{ item.item }} was not found.
+          with_items: "{{ host_vars_stat.results }}"
+
+        - name: Read inventory host vars files
+          slurp:
+            src: "{{ item.stat.path }}"
+          with_items: "{{ host_vars_stat.results }}"
+          register: host_vars_slurp
+
+        - name: Validate inventory host vars file contents
+          assert:
+            that:
+              - host_vars_content is defined
+              - host_vars_content == item.1
+          with_together:
+            - "{{ host_vars_slurp.results }}"
+            - "{{ expected_contents }}"
+          vars:
+            host_vars_content: "{{ item.0.content | b64decode }}"
+            expected_contents:
+              - |
+                ---
+                ansible_host: "1.2.3.4"
+                api_interface: "eth0"
+                bifrost_network_interface: "eth1"
+              - |
+                ---
+                ansible_host: "1.2.3.5"
+                network_interface: "eth0"
+                api_interface: "eth2"
+                storage_interface: "eth3"
+                cluster_interface: "eth4"
+                provision_interface: "eth8"
+                ironic_dnsmasq_interface: "eth9"
+                dns_interface: "eth5"
+                tunnel_interface: "eth10"
+                kolla_external_vip_interface: "eth1"
+                neutron_external_interface: "eth6,eth7"
+                neutron_bridge_name: "br0,br1"
+              - |
+                ---
+                ansible_host: "1.2.3.6"
+                network_interface: "eth0"
+                api_interface: "eth2"
+                storage_interface: "eth3"
+                tunnel_interface: "eth6"
+                neutron_external_interface: "eth4,eth5"
+                neutron_bridge_name: "br0,br1"
 
       always:
         - name: Ensure the temporary directory is removed

ansible/roles/kolla-ansible/vars/main.yml

@@ -51,6 +51,21 @@ kolla_overcloud_inventory_default: |
 # of the top level, component, and service inventories.
 kolla_overcloud_inventory: "{{ kolla_overcloud_inventory_custom or kolla_overcloud_inventory_default }}"
 
+# List of names of all top level groups in the inventory.
+kolla_overcloud_top_level_groups: >
+  {{ kolla_overcloud_inventory_top_level_group_map.values() |
+     selectattr('groups', 'defined') |
+     map(attribute='groups') |
+     sum(start=[]) |
+     unique |
+     list }}
+
+# Path to the kolla ansible seed inventory directory.
+kolla_seed_inventory_path: "{{ kolla_config_path }}/inventory/seed"
+
+# Path to the kolla ansible overcloud inventory directory.
+kolla_overcloud_inventory_path: "{{ kolla_config_path }}/inventory/overcloud"
+
 ###############################################################################
 # Feature configuration.
 

kayobe/kolla_ansible.py

@@ -87,8 +87,13 @@ def _validate_args(parsed_args, inventory_filename):
         sys.exit(1)
 
     inventory = _get_inventory_path(parsed_args, inventory_filename)
-    result = utils.is_readable_file(inventory)
+    result = utils.is_readable_dir(parsed_args.kolla_venv)
     if not result["result"]:
+        # NOTE(mgoddard): Previously the inventory was a file, now it is a
+        # directory to allow us to support inventory host_vars. Support both
+        # formats for now.
+        result_f = utils.is_readable_file(inventory)
+        if not result_f["result"]:
             LOG.error("Kolla inventory %s is invalid: %s",
                       inventory, result["message"])
             sys.exit(1)

releasenotes/notes/kolla-inventory-host-vars-7f9dc14c82e3ea20.yaml

@@ -0,0 +1,7 @@
+---
+fixes:
+  - |
+    Fixes an issue where if a host has the same name as a group that it is in,
+    configuration of kolla ansible inventory host variables could fail to
+    override the defaults. See `story 2004418
+    <https://storyboard.openstack.org/#!/story/2004418>`__ for details.