Make Bandit the default web server for new Phoenix apps

[mtrudel]

This PR:

• Makes Bandit the default web server for newly generated Phoenix apps
• Updates the Phoenix docs to reflect both Bandit and Cowboy as first-class supported adapters
• Keeps the default adapter as Cowboy if not explicitly specified for backwards compatibility
• Since Phoenix still supports (and runs CI) back to 1.11, Phoenix's internal tests are NOT updated to use Bandit here. There's a separate PR coming to add this, which will gate on Phoenix bumping to 1.12+

[mtrudel]

This is working and ready

[mtrudel]

noto bene

[josevalim]

If integration tests pass, this is good to go IMO!

[mtrudel]

Integration test failing on Plug not being loaded now that we've dropped plug_cowboy. There's likely some loading issue somewhere; I'll figure it out

[mtrudel]

Integration issue is upstream at swoosh/swoosh#857. Once this is fixed / released I'll update the dep here

[mtrudel]

Will ya look at that, all green and ready to go.

[krns]

We are using https in our local development setup and configured it like described in https://hexdocs.pm/phoenix/using_ssl.html#ssl-in-development. Today I tried Bandit but it crashes:

my-app-1       | [notice] Application my_app exited: MyApp.Application.start(:normal, []) returned an error: shutdown: failed to start child: MyAppWeb.Endpoint
my-app-1       |     ** (EXIT) shutdown: failed to start child: {MyAppWeb.Endpoint, :https}
my-app-1       |         ** (EXIT) an exception was raised:
my-app-1       |             ** (RuntimeError) Plug.SSL.configure/1 encountered error: the :otp_app option is required when setting relative SSL certfiles
my-app-1       |                 (bandit 1.1.3) lib/bandit.ex:262: Bandit.start_link/1
my-app-1       |                 (stdlib 5.2) supervisor.erl:420: :supervisor.do_start_child_i/3
my-app-1       |                 (stdlib 5.2) supervisor.erl:406: :supervisor.do_start_child/2
my-app-1       |                 (stdlib 5.2) supervisor.erl:390: anonymous fn/3 in :supervisor.start_children/2
my-app-1       |                 (stdlib 5.2) supervisor.erl:1258: :supervisor.children_map/4
my-app-1       |                 (stdlib 5.2) supervisor.erl:350: :supervisor.init_children/2
my-app-1       |                 (stdlib 5.2) gen_server.erl:980: :gen_server.init_it/2
my-app-1       |                 (stdlib 5.2) gen_server.erl:935: :gen_server.init_it/6
my-app-1       |                 (stdlib 5.2) proc_lib.erl:241: :proc_lib.init_p_do_apply/3

Maybe there are some things that are missing on our side, but I think these should be documented.

[mtrudel]

@krns yep - that's a wrinkle that you have to fix manually when using raw Bandit. In the case of Phoenix, we know for certain that we have an otp_app value so it's safe / preferable to pull it in automatically. I'm adding a change to Bandit.PhoenixAdapter to do just that. should be up in an hour or so

[mtrudel]

@krns Bandit 1.2.0 just released that should fix the issue!

[krns]

Bandit 1.2.0 works, thank you so much @mtrudel!

[chrismccord]

❤️❤️❤️🐥🔥

[mtrudel]

• https://youtu.be/ZLjWyanLHuk?t=1634