loadbalancer: Use assert on checks for readability

assert will also fail when we're not meeting the conditions, makes
clear what we're actually testing, and isn't listed as a skipped task
when the condition is ok.

Change-Id: Ia72c7052d7f9b8c7d86d74a15dcd9e003178972b

ansible/roles/loadbalancer/tasks/precheck.yml

@@ -61,14 +61,14 @@
     - not kolla_externally_managed_cert | bool
     - kolla_enable_tls_external | bool
 
-- name: Fail if external haproxy certificate is absent
+- name: Assert that external haproxy certificate exists
   run_once: true
-  fail:
-    msg: "External haproxy certificate file is not found. It is configured via 'kolla_external_fqdn_cert'"
+  assert:
+    that: haproxy_cert_file.stat.exists
+    fail_msg: "External haproxy certificate file is not found. It is configured via 'kolla_external_fqdn_cert'"
   when:
     - not kolla_externally_managed_cert | bool
     - kolla_enable_tls_external | bool
-    - not haproxy_cert_file.stat.exists
 
 - name: Checking if internal haproxy certificate exists
   run_once: true
@@ -81,26 +81,28 @@
     - not kolla_externally_managed_cert | bool
     - kolla_enable_tls_internal | bool
 
-- name: Fail if internal haproxy certificate is absent
+- name: Assert that internal haproxy certificate exists
   run_once: true
-  fail:
-    msg: "Internal haproxy certificate file is not found. It is configured via 'kolla_internal_fqdn_cert'"
+  assert:
+    that: haproxy_internal_cert_file.stat.exists
+    fail_msg: "Internal haproxy certificate file is not found. It is configured via 'kolla_internal_fqdn_cert'"
   when:
     - not kolla_externally_managed_cert | bool
     - kolla_enable_tls_internal | bool
-    - not haproxy_internal_cert_file.stat.exists
 
 - name: Checking the kolla_external_vip_interface is present
-  fail: "msg='Please check the kolla_external_vip_interface property - interface {{ kolla_external_vip_interface }} not found'"
+  assert:
+    that: kolla_external_vip_interface in ansible_facts.interfaces
+    fail_msg: "Please check the kolla_external_vip_interface property - interface {{ kolla_external_vip_interface }} not found"
   when:
     - haproxy_enable_external_vip | bool
-    - kolla_external_vip_interface not in ansible_facts.interfaces
 
 - name: Checking the kolla_external_vip_interface is active
-  fail: "msg='Please check the kolla_external_vip_interface settings - interface {{ kolla_external_vip_interface }} is not active'"
+  assert:
+    that: hostvars[inventory_hostname].ansible_facts[kolla_external_vip_interface]['active']
+    fail_msg: "Please check the kolla_external_vip_interface settings - interface {{ kolla_external_vip_interface }} is not active"
   when:
     - haproxy_enable_external_vip | bool
-    - not hostvars[inventory_hostname].ansible_facts[kolla_external_vip_interface]['active']
 
 # NOTE(hrw): let assume that each supported host OS has ping with ipv4/v6 support
 - name: Checking if kolla_internal_vip_address and kolla_external_vip_address are not pingable from any node

ansible/roles/prechecks/tasks/inventory_checks.yml

@@ -1,11 +1,12 @@
 ---
-- name: Fail if group loadbalancer not exists or it is empty
-  fail:
-    msg: >-
+- name: Checking loadbalancer group
+  assert:
+    that:
+      - groups['loadbalancer'] is defined
+      - groups['loadbalancer'] | length > 0
+    fail_msg: >-
       Inventory's group loadbalancer does not exist or it is empty.
       Please update inventory, as haproxy group was renamed
       to loadbalancer in the Xena release.
   when:
     - enable_loadbalancer | bool
-    - groups['loadbalancer'] is not defined or
-      groups['loadbalancer'] | length < 1