How to enable http/2 ?

[JensvdHeydt]

Is there an option or could you maybe add an environment variable to enable http/2 for SSL connections?

[lmakarov]

We do not currently have an option for this in place, so that's a feature request.
I wonder if having HTTP/2 enabled on the web server level (Apache, docksal/web images) would be also necessary.

[JensvdHeydt]

HTTP/2 needs an SSL connection and docksal/web doesn't use that protocol. So I'd assume it would be enough to have the proxy use ssl + http/2.
BUT: To have a fully working protocol the webserver (docksal/web for example) would have to use ssl as well.

[lmakarov]

I did some googling, but did not find a solid answer on the downsides of terminating HTTP/2 at the proxy level.

Based on my understanding, the end user gets 2 out of 3 key benefits of HTTP/2 when it's terminated at the proxy level:

• multiplexing - YES
• header compression - YES
• server push - NO

Server push would only be possible if the proxy caches responses from the origin OR if it talks to the origin over HTTP/2 and proxies pushes (not 100% positive on this one). In fact, Nginx doesn't even support server push with HTTP/2 yet (1, 2)

UPDATE: Server Push support was added in Nginx v1.13.9 (released February 20, 2018)
https://www.nginx.com/blog/nginx-1-13-9-http2-server-push/

I think terminating HTTP/2 a the proxy level should be fine, especially since we are already terminating TLS there.

Resources:

• https://http2.github.io/faq/
• https://www.nginx.com/blog/7-tips-for-faster-http2-performance/
• https://www.smashingmagazine.com/2017/04/guide-http2-server-push/

[JensvdHeydt]

Sounds great! Thanks for this very good/detailed answer!

So would it be enough to include a boolean configuration flag that set the http2-flag in the nginx-configuration of the proxy?

[JensvdHeydt]

Any news on this subject?

[lmakarov]

@JensvdHeydt no, sorry. This has not been a priority. Feel free to submit a PR, to get the ball rolling :)

[lmakarov]

This is now available in the edge image version: docksa/vhost-proxy:edge and will be release in the next release (by the end of month).

To try this out, reset vhost-proxy like this:

IMAGE_VHOST_PROXY=docksal/vhost-proxy:edge fin reset proxy

or (if using the latest develop version of Docksal):

IMAGE_VHOST_PROXY=docksal/vhost-proxy:edge fin system reset vhost-proxy

[lmakarov]

Server Push support was added in Nginx v1.13.9 (released February 20, 2018)
https://www.nginx.com/blog/nginx-1-13-9-http2-server-push/