Refresh discprov cnodes list from new identity route, to ensure newly added cnodes are integrated on registration

[SidSethi]

Trello Card Link

Description

Anytime a new creator node is registered and content is uploaded for the first time, discprovs have not peered to the new CN and will fail to fetch the new user metadata from it. This is a temporary fix for this problem: identity already has an eth-contracts connection, so we added a new route to fetch the list of registered cnodes from chain. discprov indexing task now updates its cnode_endpoints list from this route and peers with the new cnodes' ipfs node.

Services

• Discovery Provider
• Creator Node
• Identity Service
• Libs
• Contracts
• Service Commands
• Mad Dog

Does it touch a critical flow like Discovery indexing, Creator Node track upload, Creator Node gateway, or Creator Node file system?

Delete an option.

• 🚨 Yes, this touches discprov indexing (barely)

How Has This Been Tested?

Please describe the tests that you ran to verify your changes. Provide repro instructions & any configuration.
Include log analysis if applicable.

1. Deployed discprov and identity to staging with this code, confirmed it works. Registered new CN (http://54.67.117.176:31818/) on stage to ensure new IP. signed up, selected new CN as primary, and uploaded content. confirmed indexing flow queries identity and fetches new endpoints from identity

{"levelno": 20, "level": "INFO", "msg": "Redis Cache - miss registered_cnodes_from_identity", "timestamp": "2020-10-22 02:30:39,520"}
{"levelno": 20, "level": "INFO", "msg": "Fetched registered creator nodes from chain via https://identityservice.staging.audius.co/registered_creator_nodes", "timestamp": "2020-10-22 02:30:40,295"}

Confirmed Upload went through successfully on CN

Please list the unit test(s) you added to verify your changes.

[dmanjunath]

Looks good!