Run HTTP/2 integration tests against local Caddy instead of nghttp2.org (#482)

* Run HTTP/2 integration tests against local Caddy instead of nghttp2.org

The tests hitting nghttp2.org/httpbin/ had been failing on every CI run
because the upstream httpbin backend behind nghttpx returns 502 to
GitHub Actions runners. Enable h2c on the Caddy docker service (via a
new HTTPBIN_H2C_PORT, default 8081, since the existing HTTPBIN_HTTP_PORT
mapping goes directly to httpbin), point the TCP h2c test at it, and
drop the duplicate "nghttp2.org/httpbin" describe block (ping and GET
are already covered by the local "httpbin.org" block).

* Fix stray :ssl message leak in HTTP/2 integration tests

The twitter.com describe block was using @moduletag instead of
@describetag, which made its connect: {"twitter.com", 443} tag apply
to the whole module. That caused the top-level setup to open an HTTPS
connection to twitter.com even for tests outside the describe (like
the TCP h2c test), and the SSL socket's SETTINGS frame would land in
the test mailbox. The previous test had a swallow-hack comment about
"SSL messages sneaking in"; this removes the root cause.

Author: ericmj

Caddyfile

@@ -2,6 +2,9 @@
 	local_certs
 	skip_install_trust
 	storage file_system /caddy_storage
+	servers :{$HTTPBIN_HTTP_PORT:8080} {
+		protocols h1 h2c
+	}
 }
 
 https://localhost:{$HTTPBIN_HTTPS_PORT:8443} {

README.md

@@ -141,7 +141,7 @@ TINYPROXY_PORT=8887 docker compose up --detach
 TINYPROXY_PORT=8887 mix test --include proxy
 ```
 
-Available port variables: `TINYPROXY_PORT` (default 8888), `TINYPROXY_AUTH_PORT` (default 8889), `HTTPBIN_HTTP_PORT` (default 8080), `HTTPBIN_HTTPS_PORT` (default 8443).
+Available port variables: `TINYPROXY_PORT` (default 8888), `TINYPROXY_AUTH_PORT` (default 8889), `HTTPBIN_HTTP_PORT` (default 8080), `HTTPBIN_HTTPS_PORT` (default 8443), `HTTPBIN_H2C_PORT` (default 8081).
 
 ## License
 

docker-compose.yml

@@ -34,3 +34,4 @@ services:
       - "./Caddyfile:/etc/caddy/Caddyfile:z"
     ports:
       - "${HTTPBIN_HTTPS_PORT:-8443}:${HTTPBIN_HTTPS_PORT:-8443}"
+      - "${HTTPBIN_H2C_PORT:-8081}:${HTTPBIN_HTTP_PORT:-8080}"

test/mint/http2/integration_test.exs

@@ -32,14 +32,10 @@ defmodule HTTP2.IntegrationTest do
     end
   end
 
-  test "TCP - nghttp2.org" do
-    assert {:ok, %HTTP2{} = conn} = HTTP2.connect(:http, "nghttp2.org", 80)
+  test "TCP - h2c prior knowledge" do
+    assert {:ok, %HTTP2{} = conn} = HTTP2.connect(:http, HttpBin.host(), HttpBin.h2c_port())
 
-    assert {:ok, %HTTP2{} = conn, ref} = HTTP2.request(conn, "GET", "/httpbin/", [], nil)
-
-    # For some reason, we get an SSL message sneaking in here. Instead of going
-    # crazy trying to debug it, for now let's just swallow it.
-    assert_receive {:ssl, _socket, _data}, 1000
+    assert {:ok, %HTTP2{} = conn, ref} = HTTP2.request(conn, "GET", "/", [], nil)
 
     assert {:ok, %HTTP2{} = conn, responses} = receive_stream(conn)
 
@@ -105,7 +101,7 @@ defmodule HTTP2.IntegrationTest do
   end
 
   describe "twitter.com" do
-    @moduletag connect: {"twitter.com", 443}
+    @describetag connect: {"twitter.com", 443}
     @browser_user_agent "Mozilla/5.0 (Macintosh; Intel Mac OS X 11_0_1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/87.0.4280.88 Safari/537.36"
 
     test "ping", %{conn: conn} do
@@ -159,32 +155,6 @@ defmodule HTTP2.IntegrationTest do
     end
   end
 
-  describe "nghttp2.org/httpbin" do
-    @describetag connect: {"nghttp2.org", 443}
-
-    test "ping", %{conn: conn} do
-      assert {:ok, %HTTP2{} = conn, ref} = HTTP2.ping(conn)
-      assert {:ok, %HTTP2{} = conn, [{:pong, ^ref}]} = receive_stream(conn)
-      assert conn.buffer == ""
-      assert HTTP2.open?(conn)
-    end
-
-    test "GET /", %{conn: conn} do
-      assert {:ok, %HTTP2{} = conn, ref} = HTTP2.request(conn, "GET", "/httpbin/", [], nil)
-
-      assert {:ok, %HTTP2{} = conn, responses} = receive_stream(conn)
-
-      assert [{:status, ^ref, status}, {:headers, ^ref, headers} | rest] = responses
-      assert {_, [{:done, ^ref}]} = Enum.split_while(rest, &match?({:data, ^ref, _}, &1))
-
-      assert status == 200
-      assert is_list(headers)
-
-      assert conn.buffer == ""
-      assert HTTP2.open?(conn)
-    end
-  end
-
   describe "robynthinks.wordpress.com" do
     @describetag connect: {"robynthinks.wordpress.com", 443}
 

test/support/mint/http_bin.ex

@@ -17,6 +17,10 @@ defmodule Mint.HttpBin do
     get_env_port("HTTPBIN_HTTPS_PORT", 8443)
   end
 
+  def h2c_port() do
+    get_env_port("HTTPBIN_H2C_PORT", 8081)
+  end
+
   def proxy_port() do
     get_env_port("TINYPROXY_PORT", 8888)
   end