FYI, Fire Brigade version 2 will no longer be updated (latest version is 2.0.3). The newer versions 2.0.4 and higher will now be available with the original “Fire Brigade” app on Splunkbase which was just updated to support Splunk 6.3. This is noted on the page for Fire Brigade on Splunkbase: https://splunkbase.splunk.com/app/1581/
If you have any questions, ping the developer of the app @sowings
fire_brigade v2 does not have "Update monitor list from REST" saved search. fire_brigade v1 has this particular saved search. Either case requires some adjustments especially if you have distributed / clustered environment with multiple indexers (peers).
The rest API /services/data/indexes does not allow multiple peer hosts as valid entries. So you would need to run on each indexers, then append the results, dedup it and save it as csv file. Since clustered, there should not be any deviation in indexes present in one versus another peers; however why leave it to chance.
Create a saved search "Update monitor list from REST" in the context of fire brigade app, save it and have it scheduled to run in some cycle (monthly, weekly, or daily ... go nuts).
Below is how I did it in our environment. I have 10 peers, so run rest API against each indexers, then append the results, then due some filter, dedup, then save as csv as expected by fire brigade app.