Ah… ah yes!, moving to a map for headers solves that error. I tried that early but apparently got stuck on another error after without realizing, and never went back to try that. Thanks for suggesting it.
nine nines docs show this:
init(Req0=#{method := <<"GET">>}, State) ->
Req = cowboy_req:reply(200, #{
<<"content-type">> => <<"text/plain">>
}, <<"Hello world!">>, Req0),
{ok, Req, State};
In hindsight I just had to search to confirm #{} syntax in Erlang means a map in Elixir, d’oh. And I misunderstood what comes back from cowboy_req.reply, now that I can navigate Erlang code a tiny bit I can see it’s init that returns an ok-tuple, not .reply itself.
Anyway, everything works now, thanks for the assist @Sanjibukai!
Updated code
defmodule CowboyExample.Application do
use Application
def start(_type, args) do
dispatch = :cowboy_router.compile([{:, [{“/”, CowboyExample.HelloHandler, }]}])
{:ok, _} =
:cowboy.start_clear(
:my_http_listener,
[{:port, 8080}],
%{env: %{dispatch: dispatch}}
)
IO.puts("Cowboy server started on port 8080")
Supervisor.start_link([], strategy: :one_for_one, name: CowboyExample.Supervisor)
end
end
defmodule CowboyExample.HelloHandler do
def init(req, _opts) do
req = :cowboy_req.reply(200, %{“content-type” => “text/html”}, “
Hello World!
”, req){:ok, req, :nostate}
end
end
