Refactor HTTP::Server to bind to multiple addresses (crystal-lang#5776

)

* Refactor HTTP::Server to use multiple interfaces

* Remove HTTP::Server#port and add HTTP::Server#bind_unused_port

The return type is now an Socket::IPAddress instead of only the port number.

* Rename `HTTP::Server#bind` to `#bind_tcp`, add overloads to `#listen`

* Add HTTP::Server#addresses

* fixup! Refactor HTTP::Server to use multiple interfaces

* fixup! Refactor HTTP::Server to use multiple interfaces

* Add HTTP::Server.listening? and raise errors when running or closed

samples/http_server.cr

@@ -1,9 +1,9 @@
 require "http/server"
 
-server = HTTP::Server.new "0.0.0.0", 8080 do |context|
+server = HTTP::Server.new do |context|
   context.response.headers["Content-Type"] = "text/plain"
   context.response.print("Hello world!")
 end
 
 puts "Listening on http://0.0.0.0:8080"
-server.listen
+server.listen "0.0.0.0", 8080

spec/std/http/server/server_spec.cr

@@ -194,21 +194,19 @@ module HTTP
   end
 
   describe HTTP::Server do
-    it "re-sets special port zero after bind" do
-      server = Server.new(0) { |ctx| }
-      server.bind
-      server.port.should_not eq(0)
-    end
-
-    it "re-sets port to zero after close" do
-      server = Server.new(0) { |ctx| }
-      server.bind
-      server.close
-      server.port.should eq(0)
+    it "binds to unused port" do
+      server = Server.new { |ctx| }
+      address = server.bind_unused_port
+      address.port.should_not eq(0)
+
+      server = Server.new { |ctx| }
+      port = server.bind_tcp(0).port
+      port.should_not eq(0)
     end
 
     it "doesn't raise on accept after close #2692" do
-      server = Server.new("0.0.0.0", 0) { }
+      server = Server.new { }
+      server.bind_unused_port
 
       spawn do
         server.close
@@ -219,15 +217,99 @@ module HTTP
     end
 
     it "reuses the TCP port (SO_REUSEPORT)" do
-      s1 = Server.new(0) { |ctx| }
-      s1.bind(reuse_port: true)
+      s1 = Server.new { |ctx| }
+      address = s1.bind_unused_port(reuse_port: true)
 
-      s2 = Server.new(s1.port) { |ctx| }
-      s2.bind(reuse_port: true)
+      s2 = Server.new { |ctx| }
+      s2.bind_tcp(address.port, reuse_port: true)
 
       s1.close
       s2.close
     end
+
+    it "binds to different ports" do
+      server = Server.new do |context|
+        context.response.print "Test Server (#{context.request.headers["Host"]?})"
+      end
+
+      tcp_server = TCPServer.new("127.0.0.1", 0)
+      server.bind tcp_server
+      address1 = tcp_server.local_address
+
+      address2 = server.bind_unused_port
+
+      address1.should_not eq address2
+
+      spawn { server.listen }
+
+      Fiber.yield
+
+      HTTP::Client.get("http://#{address2}/").body.should eq "Test Server (#{address2})"
+      HTTP::Client.get("http://#{address1}/").body.should eq "Test Server (#{address1})"
+      HTTP::Client.get("http://#{address1}/").body.should eq "Test Server (#{address1})"
+    end
+
+    it "lists addresses" do
+      server = Server.new { }
+
+      tcp_server = TCPServer.new("127.0.0.1", 0)
+      addresses = [server.bind_unused_port, server.bind_unused_port, tcp_server.local_address]
+      server.bind tcp_server
+
+      server.addresses.should eq addresses
+    end
+
+    describe "#bind" do
+      it "fails after listen" do
+        server = Server.new { }
+        server.bind_unused_port
+        spawn { server.listen }
+        Fiber.yield
+        expect_raises(Exception, "Can't add socket to running server") do
+          server.bind_unused_port
+        end
+        server.close
+      end
+
+      it "fails after close" do
+        server = Server.new { }
+        server.bind_unused_port
+        spawn { server.listen }
+        Fiber.yield
+        server.close
+        expect_raises(Exception, "Can't add socket to closed server") do
+          server.bind_unused_port
+        end
+        server.close unless server.closed?
+      end
+    end
+
+    describe "#listen" do
+      it "fails after listen" do
+        server = Server.new { }
+        server.bind_unused_port
+        spawn { server.listen }
+        Fiber.yield
+        server.listening?.should be_true
+        expect_raises(Exception, "Can't start running server") do
+          server.listen
+        end
+        server.close
+      end
+
+      it "fails after close" do
+        server = Server.new { }
+        server.bind_unused_port
+        spawn { server.listen }
+        Fiber.yield
+        server.listening?.should be_true
+        server.close
+        server.listening?.should be_false
+        expect_raises(Exception, "Can't re-start closed server") do
+          server.listen
+        end
+      end
+    end
   end
 
   describe HTTP::Server::RequestProcessor do
@@ -310,40 +392,46 @@ module HTTP
 
   typeof(begin
     # Initialize with custom host
-    server = Server.new("0.0.0.0", 0) { |ctx| }
+    server = Server.new { |ctx| }
+    server.bind_tcp "0.0.0.0", 0
     server.listen
     server.close
 
-    server = Server.new("0.0.0.0", 0, [
+    server = Server.new([
       ErrorHandler.new,
       LogHandler.new,
       CompressHandler.new,
       StaticFileHandler.new("."),
     ]
     )
+    server.bind_tcp "0.0.0.0", 0
     server.listen
     server.close
 
-    server = Server.new("0.0.0.0", 0, [StaticFileHandler.new(".")]) { |ctx| }
+    server = Server.new([StaticFileHandler.new(".")]) { |ctx| }
+    server.bind_tcp "0.0.0.0", 0
     server.listen
     server.close
 
     # Initialize with default host
-    server = Server.new(0) { |ctx| }
+    server = Server.new { |ctx| }
+    server.bind_tcp 0
     server.listen
     server.close
 
-    server = Server.new(0, [
+    server = Server.new([
       ErrorHandler.new,
       LogHandler.new,
       CompressHandler.new,
       StaticFileHandler.new("."),
     ]
     )
+    server.bind_tcp 0
     server.listen
     server.close
 
-    server = Server.new(0, [StaticFileHandler.new(".")]) { |ctx| }
+    server = Server.new([StaticFileHandler.new(".")]) { |ctx| }
+    server.bind_tcp 0
     server.listen
     server.close
   end)

spec/std/http/web_socket_spec.cr

@@ -295,7 +295,7 @@ describe HTTP::WebSocket do
   end
 
   it "negotiates over HTTP correctly" do
-    port_chan = Channel(Int32).new
+    address_chan = Channel(Socket::IPAddress).new
 
     spawn do
       http_ref = nil
@@ -313,15 +313,15 @@ describe HTTP::WebSocket do
         end
       end
 
-      http_server = http_ref = HTTP::Server.new(0, [ws_handler])
-      http_server.bind
-      port_chan.send(http_server.port)
+      http_server = http_ref = HTTP::Server.new([ws_handler])
+      address = http_server.bind_unused_port
+      address_chan.send(address)
       http_server.listen
     end
 
-    listen_port = port_chan.receive
+    listen_address = address_chan.receive
 
-    ws2 = HTTP::WebSocket.new("ws://127.0.0.1:#{listen_port}/foo/bar?query=arg&yes=please")
+    ws2 = HTTP::WebSocket.new("ws://#{listen_address}/foo/bar?query=arg&yes=please")
 
     random = Random::Secure.hex
     ws2.on_message do |str|
@@ -334,7 +334,7 @@ describe HTTP::WebSocket do
   end
 
   it "negotiates over HTTPS correctly" do
-    port_chan = Channel(Int32).new
+    address_chan = Channel(Socket::IPAddress).new
 
     spawn do
       http_ref = nil
@@ -350,19 +350,19 @@ describe HTTP::WebSocket do
         end
       end
 
-      http_server = http_ref = HTTP::Server.new(0, [ws_handler])
+      http_server = http_ref = HTTP::Server.new([ws_handler])
       tls = http_server.tls = OpenSSL::SSL::Context::Server.new
       tls.certificate_chain = File.join(__DIR__, "../openssl/ssl/openssl.crt")
       tls.private_key = File.join(__DIR__, "../openssl/ssl/openssl.key")
-      http_server.bind
-      port_chan.send(http_server.port)
+      address = http_server.bind_unused_port
+      address_chan.send(address)
       http_server.listen
     end
 
-    listen_port = port_chan.receive
+    listen_address = address_chan.receive
 
     client_context = OpenSSL::SSL::Context::Client.insecure
-    ws2 = HTTP::WebSocket.new("127.0.0.1", port: listen_port, path: "/", tls: client_context)
+    ws2 = HTTP::WebSocket.new(listen_address.address, port: listen_address.port, path: "/", tls: client_context)
 
     random = Random::Secure.hex
     ws2.on_message do |str|

src/compiler/crystal/tools/playground/server.cr

@@ -503,15 +503,17 @@ module Crystal::Playground
         HTTP::StaticFileHandler.new(public_dir),
       ]
 
+      server = HTTP::Server.new handlers
+
       host = @host
       if host
-        server = HTTP::Server.new host, @port, handlers
+        address = server.bind_tcp host, @port
       else
-        server = HTTP::Server.new @port, handlers
-        host = "localhost"
+        address = server.bind_tcp @port
       end
+      @port = address.port
 
-      puts "Listening on http://#{host}:#{@port}"
+      puts "Listening on http://#{address}"
       if host == "0.0.0.0"
         puts "WARNING running playground with 0.0.0.0 is unsecure."
       end

src/compiler/crystal/tools/playground/views/_about.html

@@ -60,11 +60,12 @@ <h1>Usage</h1>
 <pre class="playground">
 require "http/server"
 
-server = HTTP::Server.new "0.0.0.0", 5678 do |context|
+server = HTTP::Server.new do |context|
   context.request.path
   context.response.headers["Content-Type"] = "text/plain"
   context.response.print("Hello world!")
 end
+server.bind "0.0.0.0", 5678
 
 puts "Listening on http://0.0.0.0:5678"
 server.listen</pre>

src/http/formdata.cr

@@ -12,7 +12,7 @@ require "./formdata/**"
 # require "http"
 # require "tempfile"
 #
-# server = HTTP::Server.new(8085) do |context|
+# server = HTTP::Server.new do |context|
 #   name = nil
 #   file = nil
 #   HTTP::FormData.parse(context.request) do |part|
@@ -34,6 +34,7 @@ require "./formdata/**"
 #   context.response << file.path
 # end
 #
+# server.bind 8085
 # server.listen
 # ```
 #