Replace grep and which commands with find module

For improved idempotence within the role, replace the use of `grep` and
`which` through the 'command' module with the 'find' module.
changed_when and failed_when statements around these tasks can be
removed.

Partial-Bug: 1640134
Partial-Bug: 1640144
Change-Id: Iebbcd52f673dba657117ac21ef1fa809bf344521

tasks/galera_client_install_apt.yml

@@ -57,19 +57,20 @@
 # They're only required during upgrades transitioning to a
 # statically named apt sources file.
 - name: Find old sources
-  command: >
-    grep -rnil maria /etc/apt/sources.list.d/ --exclude {{ mariadb_repo_filename }}.list
-  changed_when: false
-  failed_when: false
+  find:
+    path: "/etc/apt/sources.list.d/"
+    patterns: "^(?!{{ mariadb_repo_filename }})(.+)|(.+)(?<!{{ mariadb_repo_filename }})\\.list$"
+    contains: "^.*maria.*$"
+    use_regex: true
   register: old_sources
   tags:
     - galera-client-repos
 
 - name: Remove old sources
   file:
-    path: "{{ item }}"
+    path: "{{ item.path }}"
     state: absent
-  with_items: "{{ old_sources.stdout_lines | default([]) }}"
+  with_items: "{{ old_sources.files | default([]) }}"
   tags:
     - galera-client-repos
 

tests/test.yml

@@ -37,14 +37,18 @@
       galera_client_drop_config_file: false
   post_tasks:
     - name: Check that the mysql command is present
-      command: which mysql
+      find:
+        paths: "{{ ansible_env.PATH | regex_replace(':',',') }}"
+        patterns: "mysql"
+      register: mysql
     - name: Check .my.cnf existence
       stat:
         path: /root/.my.cnf
       register: mycnf
-    - name: Client config file .my.cnf should not exist
+    - name: mysql command should exist and client config file .my.cnf should not
       assert:
         that:
+          - "mysql.matched > 0"
           - "not mycnf.stat.exists"
 
 - name: Playbook for role testing
@@ -69,12 +73,16 @@
       galera_client_drop_config_file: true
   post_tasks:
     - name: Check that the mysql command is present
-      command: which mysql
+      find:
+        paths: "{{ ansible_env.PATH | regex_replace(':',',') }}"
+        patterns: "mysql"
+      register: mysql
     - name: Check .my.cnf existence
       stat:
         path: /root/.my.cnf
       register: mycnf
-    - name: Client config file .my.cnf should exist
+    - name: mysql command and client config file .my.cnf should exist
       assert:
         that:
+          - "mysql.matched > 0"
           - "mycnf.stat.exists"