fix(proxy): HTTP/2 verso l'upstream disattivabile (OPENVIDIA_HTTP2=0)

openvidia/config.py

@@ -77,6 +77,17 @@ def httpx_timeout_kwargs() -> dict[str, float]:
 UPSTREAM_CHAT = UPSTREAM_BASE + "chat/completions"
 
 
+def upstream_http2() -> bool:
+    """Whether upstream requests share one multiplexed HTTP/2 connection.
+
+    With HTTP/2 a single GOAWAY from the upstream (``ConnectionTerminated``)
+    kills every in-flight stream at once, and a client mid-stream sees a
+    broken event. ``OPENVIDIA_HTTP2=0`` gives each request its own HTTP/1.1
+    connection, so a closed connection costs one stream, not all of them.
+    """
+    return os.environ.get("OPENVIDIA_HTTP2", "1").strip().lower() not in ("0", "false", "no", "off")
+
+
 def outbound_proxy() -> str | None:
     """Return outbound HTTP/SOCKS5 proxy URL for upstream requests.
 

openvidia/proxy_app.py

@@ -313,7 +313,7 @@ def create_app(state: ProxyState, web_dir: Path | None = None) -> FastAPI:
     limits = httpx.Limits(max_keepalive_connections=100, max_connections=200, keepalive_expiry=30.0)
     proxy_url = config.outbound_proxy()
     client = httpx.AsyncClient(
-        http2=True,
+        http2=config.upstream_http2(),
         proxy=proxy_url if proxy_url else None,
         limits=limits,
         timeout=httpx.Timeout(**config.httpx_timeout_kwargs()),

tests/test_upstream_http2.py

@@ -0,0 +1,17 @@
+from openvidia import config
+
+
+def test_http2_is_the_default(monkeypatch):
+    monkeypatch.delenv("OPENVIDIA_HTTP2", raising=False)
+    assert config.upstream_http2() is True
+
+
+def test_http2_can_be_switched_off(monkeypatch):
+    for value in ("0", "false", "no", "off", " OFF "):
+        monkeypatch.setenv("OPENVIDIA_HTTP2", value)
+        assert config.upstream_http2() is False
+
+
+def test_any_other_value_keeps_http2(monkeypatch):
+    monkeypatch.setenv("OPENVIDIA_HTTP2", "1")
+    assert config.upstream_http2() is True