feat: Add cowboy HTTP server backend

README.md

@@ -2,7 +2,11 @@
 [![erf ci](https://github.com/nomasystems/erf/actions/workflows/ci.yml/badge.svg)](https://github.com/nomasystems/erf/actions/workflows/ci.yml)
 [![erf docs](https://github.com/nomasystems/erf/actions/workflows/docs.yml/badge.svg)](https://nomasystems.github.io/erf)
 
-`erf` is a design-first Erlang REST framework. It provides an interface to spawn specification-driven HTTP servers with several automated features that aim to ease the development, operation and maintenance of design-first RESTful services. Its HTTP protocol features are provided as a wrapper of the [elli](https://github.com/elli-lib/elli) HTTP 1.1 server.
+`erf` is a design-first Erlang REST framework. It provides an interface to spawn specification-driven HTTP servers with several automated features that aim to ease the development, operation and maintenance of design-first RESTful services.
+
+`erf` supports multiple HTTP server backends:
+- [elli](https://github.com/elli-lib/elli) - HTTP/1.1 server
+- [cowboy](https://github.com/ninenines/cowboy) - HTTP/1.1 and HTTP/2 server
 
 ## What is design-first?
 
@@ -18,10 +22,18 @@ Design-first is an approach to API development that prioritises the design of th
 
 1. Design your API using OpenAPI 3.0. For example: [users.openapi.json](examples/users/priv/users.openapi.json).
 
-2. Add `erf` as a dependency in your `rebar3` project.
+2. Add `erf` and your chosen HTTP server backend as dependencies in your `rebar3` project.
 ```erl
+%% With elli (HTTP/1.1)
+{deps, [
+    {erf, {git, "git@github.com:nomasystems/erf.git", {branch, "main"}}},
+    {elli, {git, "https://github.com/elli-lib/elli.git", {branch, "main"}}}
+]}.
+
+%% Or with cowboy (HTTP/1.1 and HTTP/2)
 {deps, [
-    {erf, {git, "git@github.com:nomasystems/erf.git", {branch, "main"}}}
+    {erf, {git, "git@github.com:nomasystems/erf.git", {branch, "main"}}},
+    {cowboy, {git, "git@github.com:ninenines/cowboy.git", {tag, "2.13.0"}}}
 ]}.
 ```
 
@@ -102,6 +114,9 @@ init([]) ->
         preprocess_middlewares => [users_preprocess],
         postprocess_middlewares => [users_postprocess],
         port => 8080
+        %% Optionally specify the HTTP server backend:
+        %% http_server => {erf_http_server_elli, #{}}      % default
+        %% http_server => {erf_http_server_cowboy, #{}}    % for HTTP/2 support
     },
     UsersChildSpec = {
         public_api_server,
@@ -156,12 +171,7 @@ The configuration is provided as map with the following type spec:
     keyfile => binary(),
     static_routes => [static_route()],
     swagger_ui => boolean(),
-    min_acceptors => pos_integer(),
-    accept_timeout => pos_integer(),
-    request_timeout => pos_integer(),
-    header_timeout => pos_integer(),
-    body_timeout => pos_integer(),
-    max_body_size => pos_integer(),
+    http_server => {module(), map()},
     log_level => logger:level()
 }.
 ```
@@ -179,14 +189,35 @@ A detailed description of each parameter can be found in the following list:
 - `keyfile`: Path to the SSL key file. Defaults to `undefined`.
 - `static_routes`: List of routes that serve static files. Defaults to `[]`.
 - `swagger_ui`: Boolean flag that enables/disables the Swagger UI. Defaults to `false`.
-- `min_acceptors`: Minimum number of acceptor processes. Defaults to `20`.
-- `accept_timeout`: Timeout in ms for accepting an incoming request. Defaults to `10000`.
-- `request_timeout`: Timeout in ms for receiving more packets when waiting for the request line. Defaults to `60000`.
-- `header_timeout`: Timeout in ms for receiving more packets when waiting for the headers. Defaults to `10000`.
-- `body_timeout`: Timeout in ms for receiving more packets when waiting for the body. Defaults to `30000`.
-- `max_body_size`: Maximum size in bytes for the body of allowed received messages. Defaults to `1024000`.
+- `http_server`: HTTP server backend and its configuration. Defaults to `{erf_http_server_elli, #{}}`.
 - `log_level`: Severity associated to logged messages. Defaults to `error`.
 
+### HTTP Server Backends
+
+#### elli (default)
+
+```erl
+http_server => {erf_http_server_elli, #{
+    min_acceptors => 20,        % Minimum number of acceptor processes
+    accept_timeout => 10000,    % Timeout in ms for accepting requests
+    request_timeout => 60000,   % Timeout in ms for the request line
+    header_timeout => 10000,    % Timeout in ms for headers
+    body_timeout => 30000,      % Timeout in ms for body
+    max_body_size => 1024000    % Maximum body size in bytes
+}}
+```
+
+#### cowboy
+
+```erl
+http_server => {erf_http_server_cowboy, #{
+    num_acceptors => 100,       % Number of acceptor processes
+    max_connections => infinity % Maximum number of connections
+}}
+```
+
+Cowboy supports both HTTP/1.1 and HTTP/2 protocols.
+
 ## Callback modules & middlewares
 
 `erf` dynamically generates a router that type check the received requests against the API specification. If the request passes the validation, it is deconstructed and passed to the middleware and callback modules. But, how do those middleware and callback modules must look like?

rebar.config

@@ -4,7 +4,6 @@
 ]}.
 
 {deps, [
-    {elli, {git, "https://github.com/elli-lib/elli.git", {branch, "main"}}},
     {ndto, {git, "https://github.com/nomasystems/ndto.git", {branch, "main"}}},
     {njson, {git, "https://github.com/nomasystems/njson.git", {branch, "main"}}}
 ]}.
@@ -33,6 +32,16 @@
 {erlfmt, [write]}.
 
 {profiles, [
+    {elli, [
+        {deps, [
+            {elli, {git, "https://github.com/elli-lib/elli.git", {branch, "main"}}}
+        ]}
+    ]},
+    {cowboy, [
+        {deps, [
+            {cowboy, {git, "git@github.com:ninenines/cowboy.git", {tag, "2.13.0"}}}
+        ]}
+    ]},
     {examples, [
         {project_app_dirs, ["examples/users", "."]},
         {shell, [
@@ -42,6 +51,9 @@
     {test, [
         {erl_opts, [nowarn_export_all]},
         {deps, [
+            {cowboy, {git, "https://github.com/ninenines/cowboy.git", {tag, "2.13.0"}}},
+            {elli, {git, "https://github.com/elli-lib/elli.git", {branch, "main"}}},
+            {gun, {git, "https://github.com/ninenines/gun.git", {tag, "2.1.0"}}},
             {meck, {git, "https://github.com/eproxus/meck.git", {branch, "master"}}},
             {nct_util, {git, "https://github.com/nomasystems/nct_util.git", {branch, "main"}}}
         ]}
@@ -89,8 +101,8 @@
 {xref_ignores, [
     erf,
     {erf_http_server, start_link, 4},
-    {erf_http_server_elli, handle, 2},
-    {erf_http_server_elli, handle_event, 3},
+    erf_http_server_cowboy,
+    erf_http_server_elli,
     {erf_router, handle, 2},
     {erf_static, mime_type, 1},
     erf_telemetry

rebar.lock

@@ -1,8 +1,4 @@
-[{<<"elli">>,
-  {git,"https://github.com/elli-lib/elli.git",
-       {ref,"c874c42b5d5c1fb7477bc1655134d1de9cbe0223"}},
-  0},
- {<<"ncalendar">>,
+[{<<"ncalendar">>,
   {git,"https://github.com/nomasystems/ncalendar.git",
        {ref,"3a36a9cfe85da197f5032ce9e4c0a4a4dea9e38e"}},
   1},

src/erf.app.src

@@ -2,8 +2,10 @@
     {description, "A design-first Erlang REST Framework"},
     {vsn, "0.1.2"},
     {registered, []},
-    {applications, [kernel, stdlib, compiler, syntax_tools, elli, ndto, njson]},
+    {applications, [kernel, stdlib, compiler, syntax_tools, ndto, njson]},
     {optional_applications, [
+        elli,
+        cowboy,
         telemetry
     ]},
     {env, []}