Bundle Caddy HTTP Proxy Server

[aaronc]

Summary

Let's bundle https://caddyserver.com in the simd, etc. binary and let it run in the same process as the state machine, REST server, etc.

Problem Definition

Operators want as simple a devops experience from the core Cosmos SDK binary as possible. CORS and TLS are commonly desired features for public facing REST endpoints.

Proposal

In continuing with #6408 which bundles the REST server and #5921 which bundles gRPC infrastructure, we can bundle a production-grade golang web/proxy server in the same binary/start cmd.

---

For Admin Use

• Not duplicate issue
• Appropriate labels applied
• Appropriate contributors tagged
• Contributor assigned/self-assigned

[alessio]

Operators want as simple a devops experience from the core Cosmos SDK binary as possible. CORS and TLS are commonly desired features for public facing REST endpoints.

If I'm not mistaken, CORS can already be enabled via command line flag. We used to have self-signed certificates and TLS in the old REST server. We first set it to disabled by default, afterwards we removed TLS altogether because it comes with more contros than pros.

On this subject, please see @greg-szabo's assesment here (with which I fully agree): #3465 (comment).

[aaronc]

If I'm not mistaken, CORS can already be enabled via command line flag.

@alessio the SDK's CORS support is currently marked as unsafe and trying to handle stuff like CORS/TLS ourselves is going to be complex and error prone. Users need an actual dedicated proxy to get the configuration correct.

That's why I am suggesting that we bundle Caddy as production-grade, golang proxy so that users that want that functionality can have it without compromise and we don't need to maintain a half-working version of CORS/TLS.

[jaekwon]

Please keep cosmos-sdk minimal.
Other projects should be able to include cosmos-sdk and add whatever they want.
All dependencies should be audited, and we don't have resources to audit caddyserver.

[aaronc]

Yep, I also think this might be a bit too involved. Closing