Adding Adittional Backends

[matiasdecarli]

This is a PR to add customs backends

The idea behind this is to add the possibility to segment some routes and send them to a different host outside Docker Cloud

For example

frontend www-https
    ...
    #docker-cloud backend routes
    acl host_api path_beg /api
    acl host_api path_beg /route1
    acl host_api path_beg /route2

    use_backend default_service if host_api
    default_backend cdn

backend default_service
    ...

backend cdn
   redirect scheme https code 301 if !{ ssl_fc }
   server s1 <some other host>:<some other port>

Additionally I've created a new flag called FORCE_DEFAULT_BACKEND that could disable the auto default_backend for cases like the example above

Any suggestion will be greatly appreciated

[matiasdecarli]

@tifayuki can you give me any feedback on this? Thanks in advance

[tifayuki]

@matiasdecarli

Sorry for the late response.
Does your changes only allow one server instruction in the additional backend?

I think we can do this similar to EXTRA_FRONTEND_SETTINGS_<PORT>, using ADDITIONAL_BACKEND_<NAME>, for example:

ADDITIONAL_BACKEND_CDN=redirect scheme https code 301 if !{ ssl_fc }, maxconn 2000, balance source, server s1 <some other host>:<some other port>, server s2 <some other host>:<some other port> check generates

backend CDN
   redirect scheme https code 301 if !{ ssl_fc }
   maxconn 2000
   balance source
   server s1 <some other host>:<some other port>
   server s2 <some other host>:<some other port> check

What do you think?

[matiasdecarli]

@tifayuki Sounds really good. I'll do these two changes in the next couple of days

• Add the name of the backend on the 'envar' name (example: 'ADDITIONAL_BACKEND_')
• Add the possibility to add +1 servers to the party 🎉

[gvilarino]

This looks awesome

[matiasdecarli]

@tifayuki Done!

An example of the behaviour

docker run -ti --name <container_name>  -e ADDITIONAL_BACKEND_backend1='redirect scheme https code 301 if !{ ssl_fc }, maxconn 2000, balance source, server s1 192.168.2.1, server s2 192.168.2.2:8888 check' -e ADDITIONAL_BACKEND_backend2='redirect scheme https code 301 if !{ ssl_fc }, maxconn 2000, balance source, server s1 192.168.1.1:8080 check' <container_id>
...
...
...
backend backend1
  redirect scheme https code 301 if !{ ssl_fc }
  maxconn 2000
  balance source
  server s1 192.168.2.1
  server s2 192.168.2.2:8888 check
backend backend2
  redirect scheme https code 301 if !{ ssl_fc }
  maxconn 2000
  balance source
  server s1 192.168.1.1:8080 check

[v13j0]

+1

[neiker]

This is nice

[gvilarino]

[matiasdecarli]

Hi @RVN-BR

Yes, this is available on my personal Docker Hub account if you wanna start testing. Any feedback is welcome

Regarding the "creating extra frontends" thing... I can't see the benefit of doing that, other than having some services running in ports different than 80 || 443. Is this the case? I'm afraid that this excedes the scope of this Pull Request

Let me know if I can help you with anything else

[matiasdecarli]

@tifayuki can we have this merged?

[tifayuki]

@matiasdecarli
Done. The code is included in 1.6.0
Thank you for the contribution :)