Address PR feedback: uv run --script, latest Python/Alpine, serve_forever

- Use #!/usr/bin/env -S uv run --script shebang with PEP 723 metadata
- Drop venv/pip multi-stage build; uv handles deps at runtime
- Upgrade to python:3.13-alpine3.23
- Unpin dependency versions (no upper bounds)
- Replace threading.Event().wait() with wsgiref serve_forever()

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

containers/transmission-exporter/Dockerfile

@@ -1,31 +1,21 @@
 # Transmission Prometheus exporter - collect-on-scrape, no polling loop
-# Two-stage build: uv installs deps into venv, runtime is minimal Alpine
+# uv run --script handles dependency resolution at runtime
 
 ARG CONTAINER_APP_VERSION=1.0.0
 
-FROM python:3.12-alpine3.22 AS base
-
-FROM base AS builder
-WORKDIR /app
-COPY --from=ghcr.io/astral-sh/uv:latest /uv /usr/local/bin/uv
-COPY exporter.py .
-RUN uv venv .venv && \
-    uv pip install --python .venv/bin/python \
-        "prometheus-client>=0.24,<1.0" \
-        "transmission-rpc>=7.0,<8.0" && \
-    find /app/.venv \( -type d -a -name test -o -name tests \) \
-      -o \( -type f -a -name '*.pyc' -o -name '*.pyo' \) -exec rm -rf '{}' \+
-
-FROM base
+FROM python:3.13-alpine3.23
 
 LABEL org.opencontainers.image.title="Transmission Exporter"
 LABEL org.opencontainers.image.description="Prometheus exporter for Transmission BitTorrent client"
 
+COPY --from=ghcr.io/astral-sh/uv:latest /uv /usr/local/bin/uv
+
 ENV PYTHONUNBUFFERED=1
+ENV UV_CACHE_DIR=/tmp/uv-cache
+
 WORKDIR /app
-COPY --from=builder /app /app
-ENV PATH="/app/.venv/bin:$PATH"
+COPY exporter.py .
 
 EXPOSE 19091
 USER 65534:65534
-CMD ["python", "-u", "/app/exporter.py"]
+CMD ["uv", "run", "--script", "/app/exporter.py"]

containers/transmission-exporter/exporter.py

@@ -1,8 +1,9 @@
+#!/usr/bin/env -S uv run --script
 # /// script
-# requires-python = ">=3.12"
+# requires-python = ">=3.13"
 # dependencies = [
-#     "prometheus-client>=0.24,<1.0",
-#     "transmission-rpc>=7.0,<8.0",
+#     "prometheus-client",
+#     "transmission-rpc",
 # ]
 # ///
 """Minimal Prometheus exporter for Transmission, using collect-on-scrape."""
@@ -10,8 +11,9 @@
 import os
 import sys
 import urllib.parse
+from wsgiref.simple_server import make_server
 
-from prometheus_client import start_http_server
+from prometheus_client import make_wsgi_app
 from prometheus_client.core import REGISTRY, GaugeMetricFamily
 from transmission_rpc import Client
 
@@ -48,7 +50,6 @@ class TransmissionCollector:
             print(f"Error collecting metrics: {e}", file=sys.stderr)
             return
 
-        # Session stats
         yield _gauge(
             "transmission_session_stats_download_speed_bytes",
             "Current download speed in bytes/s",
@@ -86,7 +87,6 @@ class TransmissionCollector:
         uploaded.add_metric(["cumulative"], session.cumulative_stats.uploaded_bytes)
         yield uploaded
 
-        # Per-torrent metrics
         t_download = GaugeMetricFamily(
             "transmission_torrent_download_bytes",
             "Torrent total downloaded bytes",
@@ -142,12 +142,8 @@ def main():
     REGISTRY.register(TransmissionCollector(client_kwargs))
 
     print(f"Listening on :{port}, scraping {addr}")
-    start_http_server(port)
-
-    # Block forever
-    import threading
-
-    threading.Event().wait()
+    httpd = make_server("", port, make_wsgi_app())
+    httpd.serve_forever()
 
 
 if __name__ == "__main__":