Add health reporting, container probe, and JNN channel support

epg/server.py

@@ -0,0 +1,41 @@
+"""Serve generated files and a live, locally computed health endpoint."""
+import json
+import os
+from functools import partial
+from http.server import SimpleHTTPRequestHandler, ThreadingHTTPServer
+from urllib.parse import urlsplit
+from epg.health import evaluate
+
+
+class Handler(SimpleHTTPRequestHandler):
+    def do_GET(self):
+        if urlsplit(self.path).path.rstrip('/') == '/health':
+            self.health()
+        else:
+            super().do_GET()
+
+    def do_HEAD(self):
+        if urlsplit(self.path).path.rstrip('/') == '/health':
+            self.health(head=True)
+        else:
+            super().do_HEAD()
+
+    def health(self, head=False):
+        try:
+            report = evaluate()
+        except Exception:
+            report = {'status': 'unhealthy', 'error': 'Health evaluation failed'}
+        body = json.dumps(report).encode()
+        self.send_response(503 if report['status'] == 'unhealthy' else 200)
+        self.send_header('Content-Type', 'application/json')
+        self.send_header('Cache-Control', 'no-store')
+        self.send_header('Content-Length', str(len(body)))
+        self.end_headers()
+        if not head:
+            self.wfile.write(body)
+
+
+if __name__ == '__main__':
+    server = ThreadingHTTPServer(('', int(os.environ.get('PORT', '1876'))),
+                                partial(Handler, directory='/app/output'))
+    server.serve_forever()