Local address support.

httpcore/_async/connection.py

@@ -23,11 +23,13 @@ def __init__(
         http2: bool = False,
         ssl_context: SSLContext = None,
         socket: AsyncSocketStream = None,
+        local_addr: bytes = None,
     ):
         self.origin = origin
         self.http2 = http2
         self.ssl_context = SSLContext() if ssl_context is None else ssl_context
         self.socket = socket
+        self.local_addr = local_addr
 
         if self.http2:
             self.ssl_context.set_alpn_protocols(["http/1.1", "h2"])
@@ -98,7 +100,7 @@ async def _open_socket(self, timeout: TimeoutDict = None) -> AsyncSocketStream:
         ssl_context = self.ssl_context if scheme == b"https" else None
         try:
             return await self.backend.open_tcp_stream(
-                hostname, port, ssl_context, timeout
+                hostname, port, ssl_context, timeout, self.local_addr
             )
         except Exception:
             self.connect_failed = True

httpcore/_async/connection_pool.py

@@ -76,6 +76,7 @@ class AsyncConnectionPool(AsyncHTTPTransport):
     * **keepalive_expiry** - `Optional[float]` - The maximum time to allow
     before closing a keep-alive connection.
     * **http2** - `bool` - Enable HTTP/2 support.
+    * **local_addr** - `Optional[bytes]` - Local address to connect from
     """
 
     def __init__(
@@ -85,12 +86,14 @@ def __init__(
         max_keepalive: int = None,
         keepalive_expiry: float = None,
         http2: bool = False,
+        local_addr: bytes = None,
     ):
         self._ssl_context = SSLContext() if ssl_context is None else ssl_context
         self._max_connections = max_connections
         self._max_keepalive = max_keepalive
         self._keepalive_expiry = keepalive_expiry
         self._http2 = http2
+        self._local_addr = local_addr
         self._connections: Dict[Origin, Set[AsyncHTTPConnection]] = {}
         self._thread_lock = ThreadLock()
         self._backend = AutoBackend()
@@ -141,7 +144,10 @@ async def request(
 
                 if connection is None:
                     connection = AsyncHTTPConnection(
-                        origin=origin, http2=self._http2, ssl_context=self._ssl_context,
+                        origin=origin,
+                        http2=self._http2,
+                        ssl_context=self._ssl_context,
+                        local_addr=self._local_addr,
                     )
                     logger.trace("created connection=%r", connection)
                     await self._add_to_pool(connection, timeout=timeout)

httpcore/_backends/asyncio.py

@@ -222,13 +222,20 @@ async def open_tcp_stream(
         port: int,
         ssl_context: Optional[SSLContext],
         timeout: TimeoutDict,
+        local_addr: Optional[bytes],
     ) -> SocketStream:
         host = hostname.decode("ascii")
         connect_timeout = timeout.get("connect")
         exc_map = {asyncio.TimeoutError: ConnectTimeout, OSError: ConnectError}
         with map_exceptions(exc_map):
+            local_addrport = None
+            if local_addr:
+                local_addrport = (local_addr, 0)
             stream_reader, stream_writer = await asyncio.wait_for(
-                asyncio.open_connection(host, port, ssl=ssl_context), connect_timeout,
+                asyncio.open_connection(
+                    host, port, ssl=ssl_context, local_addr=local_addrport
+                ),
+                connect_timeout,
             )
             return SocketStream(
                 stream_reader=stream_reader, stream_writer=stream_writer

httpcore/_backends/auto.py

@@ -34,8 +34,11 @@ async def open_tcp_stream(
         port: int,
         ssl_context: Optional[SSLContext],
         timeout: TimeoutDict,
+        local_addr: Optional[bytes],
     ) -> AsyncSocketStream:
-        return await self.backend.open_tcp_stream(hostname, port, ssl_context, timeout)
+        return await self.backend.open_tcp_stream(
+            hostname, port, ssl_context, timeout, local_addr
+        )
 
     def create_lock(self) -> AsyncLock:
         return self.backend.create_lock()

httpcore/_backends/base.py

@@ -76,6 +76,7 @@ async def open_tcp_stream(
         port: int,
         ssl_context: Optional[SSLContext],
         timeout: TimeoutDict,
+        local_addr: Optional[bytes],
     ) -> AsyncSocketStream:
         raise NotImplementedError()  # pragma: no cover
 

httpcore/_backends/sync.py

@@ -125,13 +125,17 @@ def open_tcp_stream(
         port: int,
         ssl_context: Optional[SSLContext],
         timeout: TimeoutDict,
+        local_addr: Optional[bytes],
     ) -> SyncSocketStream:
         address = (hostname.decode("ascii"), port)
         connect_timeout = timeout.get("connect")
         exc_map = {socket.timeout: ConnectTimeout, socket.error: ConnectError}
 
         with map_exceptions(exc_map):
-            sock = socket.create_connection(address, connect_timeout)
+            local_addrport = None
+            if local_addr:
+                local_addrport = (local_addr, 0)
+            sock = socket.create_connection(address, connect_timeout, local_addrport)  # type: ignore
             if ssl_context is not None:
                 sock = ssl_context.wrap_socket(
                     sock, server_hostname=hostname.decode("ascii")

httpcore/_backends/trio.py

@@ -140,7 +140,10 @@ async def open_tcp_stream(
         port: int,
         ssl_context: Optional[SSLContext],
         timeout: TimeoutDict,
+        local_addr: Optional[bytes],
     ) -> AsyncSocketStream:
+        if local_addr:
+            raise NotImplementedError()
         connect_timeout = none_as_inf(timeout.get("connect"))
         exc_map = {
             trio.TooSlowError: ConnectTimeout,

httpcore/_sync/connection.py

@@ -23,11 +23,13 @@ def __init__(
         http2: bool = False,
         ssl_context: SSLContext = None,
         socket: SyncSocketStream = None,
+        local_addr: bytes = None,
     ):
         self.origin = origin
         self.http2 = http2
         self.ssl_context = SSLContext() if ssl_context is None else ssl_context
         self.socket = socket
+        self.local_addr = local_addr
 
         if self.http2:
             self.ssl_context.set_alpn_protocols(["http/1.1", "h2"])
@@ -98,7 +100,7 @@ def _open_socket(self, timeout: TimeoutDict = None) -> SyncSocketStream:
         ssl_context = self.ssl_context if scheme == b"https" else None
         try:
             return self.backend.open_tcp_stream(
-                hostname, port, ssl_context, timeout
+                hostname, port, ssl_context, timeout, self.local_addr
             )
         except Exception:
             self.connect_failed = True

httpcore/_sync/connection_pool.py

@@ -76,6 +76,7 @@ class SyncConnectionPool(SyncHTTPTransport):
     * **keepalive_expiry** - `Optional[float]` - The maximum time to allow
     before closing a keep-alive connection.
     * **http2** - `bool` - Enable HTTP/2 support.
+    * **local_addr** - `Optional[bytes]` - Local address to connect from
     """
 
     def __init__(
@@ -85,12 +86,14 @@ def __init__(
         max_keepalive: int = None,
         keepalive_expiry: float = None,
         http2: bool = False,
+        local_addr: bytes = None,
     ):
         self._ssl_context = SSLContext() if ssl_context is None else ssl_context
         self._max_connections = max_connections
         self._max_keepalive = max_keepalive
         self._keepalive_expiry = keepalive_expiry
         self._http2 = http2
+        self._local_addr = local_addr
         self._connections: Dict[Origin, Set[SyncHTTPConnection]] = {}
         self._thread_lock = ThreadLock()
         self._backend = SyncBackend()
@@ -141,7 +144,10 @@ def request(
 
                 if connection is None:
                     connection = SyncHTTPConnection(
-                        origin=origin, http2=self._http2, ssl_context=self._ssl_context,
+                        origin=origin,
+                        http2=self._http2,
+                        ssl_context=self._ssl_context,
+                        local_addr=self._local_addr,
                     )
                     logger.trace("created connection=%r", connection)
                     self._add_to_pool(connection, timeout=timeout)

tests/async_tests/test_interfaces.py

@@ -204,6 +204,25 @@ async def test_http_proxy(
         assert reason == b"OK"
 
 
+@pytest.mark.parametrize("local_addr", [b"0.0.0.0"])
+@pytest.mark.asyncio
+# This doesn't run with trio, since trio doesn't support local_addr.
+async def test_http_request_local_addr(local_addr: str) -> None:
+    async with httpcore.AsyncConnectionPool(local_addr=local_addr) as http:
+        method = b"GET"
+        url = (b"http", b"example.org", 80, b"/")
+        headers = [(b"host", b"example.org")]
+        http_version, status_code, reason, headers, stream = await http.request(
+            method, url, headers
+        )
+        body = await read_body(stream)
+
+        assert http_version == b"HTTP/1.1"
+        assert status_code == 200
+        assert reason == b"OK"
+        assert len(http._connections[url[:3]]) == 1  # type: ignore
+
+
 # mitmproxy does not support forwarding HTTPS requests
 @pytest.mark.parametrize("proxy_mode", ["DEFAULT", "TUNNEL_ONLY"])
 @pytest.mark.usefixtures("async_environment")

tests/sync_tests/test_interfaces.py

@@ -204,6 +204,25 @@ def test_http_proxy(
         assert reason == b"OK"
 
 
+@pytest.mark.parametrize("local_addr", [b"0.0.0.0"])
+
+# This doesn't run with trio, since trio doesn't support local_addr.
+def test_http_request_local_addr(local_addr: str) -> None:
+    with httpcore.SyncConnectionPool(local_addr=local_addr) as http:
+        method = b"GET"
+        url = (b"http", b"example.org", 80, b"/")
+        headers = [(b"host", b"example.org")]
+        http_version, status_code, reason, headers, stream = http.request(
+            method, url, headers
+        )
+        body = read_body(stream)
+
+        assert http_version == b"HTTP/1.1"
+        assert status_code == 200
+        assert reason == b"OK"
+        assert len(http._connections[url[:3]]) == 1  # type: ignore
+
+
 # mitmproxy does not support forwarding HTTPS requests
 @pytest.mark.parametrize("proxy_mode", ["DEFAULT", "TUNNEL_ONLY"])