feat: lazy load and hot reload for policies

[ravikp7]

• only load policies defined in the gateway config

fixes #870

[codecov]

Codecov Report

Merging #890 into master will increase coverage by 0.26%.
The diff coverage is 91.93%.

@@            Coverage Diff             @@
##           master     #890      +/-   ##
==========================================
+ Coverage   88.82%   89.08%   +0.26%     
==========================================
  Files         136      137       +1     
  Lines        3695     3711      +16     
==========================================
+ Hits         3282     3306      +24     
+ Misses        413      405       -8

Impacted Files	Coverage Δ
lib/policies/index.js	100% <100%> (ø)	⬆️
lib/policies/oauth2/oauth2.js	88.05% <100%> (+0.18%)	⬆️
lib/policies/basic-auth/basic-auth.js	100% <100%> (+7.69%)	⬆️
lib/config/config.js	90.42% <100%> (+0.1%)	⬆️
lib/policies/oauth2/index.js	100% <100%> (ø)	⬆️
lib/gateway/index.js	94.11% <86.95%> (-2.38%)	⬇️
lib/policies/basic-auth/registerStrategy.js	91.3% <91.3%> (ø)
lib/rest/index.js	91.11% <0%> (+7.39%)	⬆️
lib/conditions/json-schema.js	63.63% <0%> (+18.63%)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 91b62b0...dabeac1. Read the comment docs.

[XVincentX]

Good start.

I'd like to get a clarification on why you needed to load some policies in the tests although these are not used.

Another thing that needs to be verified is whether, by making an hot reload with a new policy, it gets loaded correctly and does not make the gateway crash.

Having a test checking this functionality would be great!

Good work though!

[XVincentX]

This looks promising, I can definitely see some progress. I've left another round of comments and I'm right now looking into the tests to figure out and fix the issue you were facing.

[ravikp7]

@XVincentX Do we also need to remove policies which are removed from the config on hot reload?

[XVincentX]

@ravikp7 No; they're on memory already so it does not make sense to unload them. In any case I took care of it and I'm adding an e2e test. See the code in case you're interested!