Bug 1396227

As per the meeting, I have split out the original bz:

-dry run parts B and C:

https://bugzilla.redhat.com/show_bug.cgi?id=1465577

-‘do you really want to do this’ user question parts D:

https://bugzilla.redhat.com/show_bug.cgi?id=1465574

-lock down parts E:

https://bugzilla.redhat.com/show_bug.cgi?id=1465569

Docs effort only for this BZ:

a. Modify documentation to describe in more detail consequences and behaviour of overcloud modify operations. 

The current v9 documentation says little about the possible nature, scope and impact of overcloud modifications. 
https://access.redhat.com/documentation/en/red-hat-openstack-platform/9/single/director-installation-and-usage#sect-Modifying_the_Overcloud_Environment
“…. The director checks the overcloud stack in heat, and then updates each item in the stack with the environment files and heat templates. It does not recreate the Overcloud, but rather changes the existing Overcloud. …“


b. Provide a description of changes that will be made and the end result when deploy and update operations are invoked
For director operations which will change the overcloud configuration, provide a report of changes that will be made and why, and then the overall result against these changes when complete.

This bugzilla has been removed from the release since it has not been triaged, and needs to be reviewed for targeting another release.

Scoping old BZ.

Brad - In terms of a) and b), how specific should we go in terms of defining changes? Should we talk mostly about configuration stages (i.e. Step 1 to 5)?

I guess, I'm looking for a bit more detail on what things we should be saying to customers in this regard?

Dan, 
Errors to warn people against stem from not really knowing what is in the yaml files before they launch a redeploy. Could be no configuration control , confusion, bad edits etc. Major two examples I'm aware of are:
- they thought they were scaling out and didn't realize the yaml networking section was completely different from what was currently deployed -  so all networks/communication breaks w/redeploy
- they thought they where updating networking but use either stale commandline flags or nodeinfo.yaml and do a drastic scale down of overcloud nodes to some typical hello world baseline 3 controllers and 2 computes
Perhaps you could use the above examples with a highlevel statement warning like - "the yaml files that define your cloud are numerous and complex. before you redeploy your cloud you need to ensure you understand the exact differences from the last deployment or you could get unexpected and disruptive consequences. For example ...."

Scoping old bugs. This BZ might still be useful to implement. It's work adding the suggestion Brad identified in comment #5 in the following section:

https://access.redhat.com/documentation/en-us/red_hat_openstack_platform/13/html/director_installation_and_usage/chap-performing_tasks_after_overcloud_creation#sect-Modifying_the_Overcloud_Environment

Closing; warning notes added per comment 6.