Add HTTP2 (and HTTP3) support in NGINX containers

[maxpatiiuk]

These will bring performance improvements and future-proofing

Enabling them in dev containers and production containers would be great

[CarolineDenis]

Cannot be used without HTTPS,
=> #2607
not wise to have different environments between development and production.

[maxpatiiuk]

More context:
Http2 can't really be used without HTTPs (#2607)
HTTPs wasn't added in development because that would additional configuration step to docker setup (#2607 (comment))
Could enable Http2/Http3 just in production, but it's not advisable to have different configs between production and development (as then issues affecting just production would be uncaught)

[maxpatiiuk]

From @grantfitzsimmons:

https://caniuse.com/http2

HTTP/2 is only supported over TLS (HTTPS).

Browsers impose a per-domain limit of 6-8 connections when using HTTP/1.1, depending on the browser implementation. This allows at most 6-8 concurrent requests per domain.

With HTTP/2, browsers open only 1 connection per domain. However, thanks to the multiplexing feature of the HTTP/2 protocol, the number of concurrent requests per domain is not limited to 6-8, but it is virtually unlimited.

Source: Stack Overflow

This would get around issues involved with the stats page being limited to 6-8 concurrent requests at a given time.

This would require self-hosted institutions and developers to create certificates in development as it requires TLS, but this is not difficult to set up for most users.

@maxpatiiuk @realVinayak – Please add more information, corrections, or comments if necessary 😄

[grantfitzsimmons]

Quoting Max:

@realVinayak had great insight that this could possibly be caused by HTTP 1.1, as it has a limit of 6 simultaneous requests.
We should test if this if fixed when the web server is updated to use http2 or even http3 instead - #2608