I would be +1 on TO API routing blacklist. I think it is a great idea to allow us to continue to move fast while minimizing risk.
I do agree we should expose the current state of the blacklist as an API endpoint as to easily get insight into the current configuration. We could even make the blacklist driven by the API instead of a JSON config file. Michael On 10/31/19, 4:18 PM, "Gray, Jonathan" <[email protected]> wrote: Not trying to sideswipe, but could we expose that as an endpoint with a Golang list as well to solve: https://github.com/apache/trafficcontrol/issues/2872 Jonathan G On 10/31/19, 3:51 PM, "Rawlin Peters" <[email protected]> wrote: Hey all, We've been picking up momentum in the TO Perl -> Go rewrite recently, which has gotten me thinking of ways to reduce the risk of possible regressions in the rewritten APIs. I'd like to propose that we implement a sort of "routing blacklist" for the TO API routes. At a high level, this blacklist would be a simple JSON config file like this: { "perlRoutes": [ {"method": "GET", "path": "/api/1.1/foos"}, {"method": "POST", "path": "/api/1.1/foos"} ], "disabledRoutes": [ {"method": "GET", "path": "/api/1.1/foos"}, {"method": "POST", "path": "/api/1.1/foos"} ] } APIs in "perlRoutes" would be explicitly routed to the Perl, even if the Go route exists and could handle the request. The primary use case for this feature would be to deploy an upgraded version of TO-Go with rewritten APIs without having TO-Go handle the requests yet. Post-upgrade, you could remove a rewritten route from the blacklist on a single TO instance, validate it for some period of time, then roll out the rewritten API to other TO instances by removing the API from their blacklists. APIs in "disabledRoutes" would be explicitly disabled. The use cases for this field would include: - disabling endpoints that are part of an incomplete feature and don't really make sense to use on their own yet - disabling endpoints that have known, serious issues that should be disabled immediately This would make it easier to plug holes in TO without having to rebuild and redeploy. Ideally, this config file would be SIGHUP-able so that it can be reconfigured without having to restart TO. Also, there should be a hardcoded list of "Perl-routable" routes within TO-Go, so that you can't just depend on Perl forever if you wanted. I would propose that newly rewritten routes be added to this hardcoded list in TO-Go. Then after being in one release as "Perl-routable", they would become "non-Perl-routable" in the following release. IMO we could've used something like this since the beginning of the TO Perl -> Go rewrite effort, but we still do have a decent amount of routes left that this could be useful for. Please let me know what you think. If we're generally +1 on this idea, I'll throw together a blueprint with more details, then maybe I can convince my boss to let me work on it ;) - Rawlin
