Random Ansible stuff -- commenting out variables

I am currently learning Ansible.  This is due to the fact that I realized I had to have a way to simultaneously configure many servers: I was up to using 6 (six) virtual centOS servers to learn glusterfs and manually coniguring each one was geting troublesome.  Anyhow I think I am a week into this already.

Todays lesson is: How to replace variables with comments on top.  This is a personal favorite style of mine, specifically in the form:

   # Previous value was VAR=value changed 20170504
   VAR=newvalue

I use this variable A LOT, in fact on all of my configuration changes whenever I can. 

Here are two examples from my personal tests.

One way is to simply use newlines:

         This task:
         ====================================================
         - name: positional backrefs embedded newline hacks
           lineinfile:
              dest: /tmp/testconfig.cfg
              regexp: '^(TESTCONFIGVAR9)=(.*)'
              line: '# \1 modified {{mod_timestamp_long}}
                    \n# \1 = (old value was) \2
                    \n\1=newvalue'
              backrefs: yes
              state: present
         ====================================================
         Produces this output:
         ====================================================
         # TESTCONFIGVAR9 modified 20170504T001157
         # TESTCONFIGVAR9 = (old value was) test
         TESTCONFIGVAR9=newvalue
         ====================================================

Another way is to split up the task:

         These tasks:
         ====================================================
         - name: another attempt at custom mod notes, step 1
           lineinfile:
              dest: /tmp/testconfig.cfg
              regexp: '^(TESTCONFIGVAR6=.*)'
              line: '# OLD VALUE: \1 {{ mod_timestamp_long }}'
              backrefs: yes
         - name: another attempt at custom mod notes, step 2
           lineinfile:
              dest: /tmp/testconfig.cfg
              insertafter: '# OLD VALUE: '
              line: 'TESTCONFIGVAR6=blahblahblah'
         ====================================================
         Result in this output:
         ====================================================
         # OLD VALUE: TESTCONFIGVAR6=test 20170504T001157
         TESTCONFIGVAR6=blahblahblah
         ====================================================

If anybody is reading this, I am open to suggestions (since I am still learning this at the moment).

JondZ Thu May  4 00:16:35 EDT 2017