Allow mysql_username and mysql_password to be passed via env var.

This change allows mysql_username and mysql_password to be passed to
bifrost-ironic-install via the environment variables mysql_user and
mysql_pass. This is useful when there is a preexisting mysql installation
with passwords alreay set.

Change-Id: I6dfd3ec0e769f0af6b157cde106885eabc24d120

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

@@ -136,6 +136,16 @@
     write_priv: ".*"
     read_priv: ".*"
   no_log: true
+- name: "Set mysql_username if environment variable mysql_user is set"
+  set_fact:
+    mysql_username: "{{ lookup('env', 'mysql_user') }}"
+  when: lookup('env', 'mysql_user') | length > 0
+  no_log: true
+- name: "Set mysql_password if environment variable mysql_pass is set"
+  set_fact:
+    mysql_password: "{{ lookup('env', 'mysql_pass') }}"
+  when: lookup('env', 'mysql_pass') | length > 0
+  no_log: true
 - name: "MySQL - Creating DB"
   mysql_db:
     name: "ironic"

releasenotes/notes/Add-env-var-support-for-mysql-user-password-3ac520eea7ea9807.yaml

@@ -0,0 +1,7 @@
+---
+features:
+  - Add support for passing a Mysql username and password
+    via environment variables mysql_user for username and
+    mysql_pass for password. Useful for cases where Mysql
+    server may be existing and have usernames with password
+    already set.