Add Gitea build, container tests and registry publication

ci/runner/configure-docker.py

@@ -0,0 +1,32 @@
+#!/usr/bin/env python3
+"""Merge this project's HTTP registry into a selected daemon JSON file."""
+import json
+from pathlib import Path
+import shutil
+import sys
+
+if len(sys.argv) != 2:
+    sys.exit('Usage: python3 ci/runner/configure-docker.py <daemon.json>')
+path = Path(sys.argv[1]).expanduser()
+data = json.loads(path.read_text()) if path.exists() else {}
+registries = data.setdefault('insecure-registries', [])
+if not isinstance(registries, list):
+    sys.exit('Existing insecure-registries must be an array; configuration left unchanged')
+if '192.168.2.28:3000' in registries:
+    print('Internal registry already configured; no change')
+    sys.exit(0)
+registries.append('192.168.2.28:3000')
+path.parent.mkdir(parents=True, exist_ok=True)
+if path.exists():
+    backup = path.with_name(path.name + '.before-agiledancers')
+    if not backup.exists():
+        shutil.copy2(path, backup)
+# Write in the same directory, then replace atomically.
+temporary = path.with_name(path.name + '.agiledancers.tmp')
+with temporary.open('x') as output:
+    json.dump(data, output, indent=2)
+    output.write('\n')
+if path.exists():
+    shutil.copymode(path, temporary)
+temporary.replace(path)
+print('Internal registry added; restart/apply Docker Engine configuration to activate')