Make HTTP port configurable with default 1876

Containerfile

@@ -5,8 +5,8 @@ COPY epg ./epg
 COPY tvj_epj.py .
 RUN pip install --no-cache-dir requests
 
-ENV UPDATE_INTERVAL=6
-EXPOSE 8787
+ENV UPDATE_INTERVAL=6 PORT=1876
+EXPOSE 1876
 COPY entrypoint.sh /entrypoint.sh
 RUN chmod +x /entrypoint.sh
 ENTRYPOINT ["/entrypoint.sh"]

README.md

@@ -10,7 +10,7 @@ Build this checkout and select both channels:
 
 ```sh
 podman build -t tvj-epg .
-podman run -d --name tvj-epg -p 8787:8787 \
+podman run -d --name tvj-epg -p 1876:1876 \
   -e TZ=America/Jamaica \
   -e CHANNELS=tvj,tvjsn \
   -e UPDATE_INTERVAL=3 \
@@ -20,8 +20,12 @@ podman run -d --name tvj-epg -p 8787:8787 \
 With no `CHANNELS` setting, only TVJ is included, preserving the default behavior.
 Use `CHANNELS=tvjsn` for TVJ Sports Network alone.
 
-- Playlist: `http://localhost:8787/tvj.m3u`
-- Guide: `http://localhost:8787/tvj.xml`
+- Playlist: `http://localhost:1876/tvj.m3u`
+- Guide: `http://localhost:1876/tvj.xml`
+
+To use a different port, set `PORT` and match the container port in the mapping,
+for example `-e PORT=8787 -p 8787:8787`. Recreating an existing container requires
+updating its port mapping for the new default.
 
 Both files contain the selected channels. Their XMLTV IDs and playlist `tvg-id`
 values match automatically. Outputs become available after the first successful
@@ -31,6 +35,7 @@ update. Stream access is determined by the stream provider.
 
 | Variable | Default | Meaning |
 | --- | --- | --- |
+| `PORT` | `1876` | HTTP listening port (1–65535) |
 | `CHANNELS` | `tvj` | Comma-separated built-in channel keys; unknown keys fail startup |
 | `UPDATE_INTERVAL` | `6` | Positive integer refresh interval in hours |
 | `TZ` | Container timezone | Logging timezone; XMLTV timestamps remain UTC |

entrypoint.sh

@@ -1,6 +1,10 @@
 #!/bin/sh
 set -eu
 
+PORT="${PORT-1876}"
+export PORT
+PORT="$(python -c 'import os; value = os.environ["PORT"]; valid = value.isascii() and value.isdigit() and 1 <= int(value) <= 65535; valid or exit("PORT must be an integer from 1 to 65535"); print(int(value))')"
+
 mkdir -p /app/output
 UPDATE_INTERVAL="${UPDATE_INTERVAL:-6}"
 export UPDATE_INTERVAL
@@ -18,4 +22,4 @@ python -c 'from epg.config import load; load()'
 ) &
 
 cd /app/output
-exec python3 -m http.server 8787
+exec python3 -m http.server "$PORT"