Implement resilient register_app config reload

usr/bin/vmmgr

@@ -9,9 +9,10 @@ subparsers = parser.add_subparsers()
 
 parser_register_app = subparsers.add_parser('register-app')
 parser_register_app.set_defaults(action='register-app')
-parser_register_app.add_argument('app')
+parser_register_app.add_argument('app', help='Application name')
-parser_register_app.add_argument('login', nargs='?')
+parser_register_app.add_argument('host', help='Application subdomain')
-parser_register_app.add_argument('password', nargs='?')
+parser_register_app.add_argument('login', nargs='?', help='Admin login')
+parser_register_app.add_argument('password', nargs='?', help='Admin password')
 
 parser_rebuild_issue = subparsers.add_parser('rebuild-issue')
 parser_rebuild_issue.set_defaults(action='rebuild-issue')
@@ -43,7 +44,7 @@ vmmgr = VMMgr(conf)
 lxcmgr = LXCMgr(conf)
 if args.action == 'register-app':
     # Used by app install scripts
-    vmmgr.register_app(args.app, args.login, args.password)
+    vmmgr.register_app(args.app, args.host, args.login, args.password)
 elif args.action == 'rebuild-issue':
     # Used on VM startup
     vmmgr.rebuild_issue()

usr/lib/python3.6/vmmgr/appmgr.py

@@ -70,15 +70,18 @@ class AppMgr:
         with subprocess.Popen(['apk', '--progress-fd', str(pipe_wfd), '--no-cache', 'add', 'vm-{}@vm'.format(item.key)], pass_fds=[pipe_wfd]) as p:
             while p.poll() == None:
                 time.sleep(0.1)
+                # Read pipe
                 data = b''
                 while True:
                     chunk = os.read(pipe_rfd, 8192)
                     data += chunk
                     if len(chunk) < 8192:
                         break
+                # Parse last apk progress line
                 progress = data.decode().splitlines()[-1].split('/')
                 item.data.bytes_downloaded = progress[0]
                 item.data.bytes_total = progress[1]
+        # Close pipe
         os.close(pipe_rfd)
         os.close(pipe_wfd)
 

usr/lib/python3.6/vmmgr/vmmgr.py

@@ -17,12 +17,18 @@ class VMMgr:
         self.domain = conf['host']['domain']
         self.port = conf['host']['port']
 
-    def register_app(self, app, login, password):
+    def register_app(self, app, host, login, password):
-        # Register newly installed application and its credentials
+        # Register newly installed application, its subdomain and credentials
-        self.conf['apps'][app] = {'login': login if login else 'N/A',
+        self.conf['apps'][app] = {'host': host,
+                                  'login': login if login else 'N/A',
                                   'password': password if password else 'N/A',
                                   'visible': False}
         self.conf.save()
+        # Attempt to contact running vmmgr WSGI application to reload config
+        try:
+            requests.get('https://127.0.0.1/reload-config', timeout=3)
+        except:
+            pass
 
     def update_host(self, domain, port):
         # Update domain and port and rebuild all configuration. Web interface calls restart_nginx() in WSGI close handler

usr/lib/python3.6/vmmgr/wsgiapp.py

@@ -62,6 +62,9 @@ class WSGIApp:
             Rule('/shutdown-vm', endpoint='shutdown_vm_action'),
             Rule('/reboot-vm', endpoint='reboot_vm_action')
         ))
+        self.localhost_url_map = Map((
+            Rule('/reload-config', endpoint='reload_config_action')
+        ))
 
     def __call__(self, environ, start_response):
         return self.wsgi_app(environ, start_response)
@@ -76,7 +79,12 @@ class WSGIApp:
         return response(environ, start_response)
 
     def dispatch_request(self, request):
-        url_map = self.admin_url_map if request.session['admin'] else self.url_map
+        if request.session['admin']:
+            url_map = self.admin_url_map
+        elif request.remote_addr in ('127.0.0.1', '::1'):
+            url_map = self.localhost_url_map
+        else:
+            url_map = self.url_map
         adapter = url_map.bind_to_environ(request.environ)
         try:
             endpoint, values = adapter.match()
@@ -386,5 +394,10 @@ class WSGIApp:
         response.call_on_close(self.appmgr.shutdown_vm)
         return response
 
+    def reload_config_action(self, request):
+        # Reload configuration (called by vmmgr.register_app())
+        self.config.load()
+        return Response(status=204)
+
     def is_app_visible(self, app):
         return app in self.conf['apps'] and self.conf['apps'][app]['visible'] and self.appmgr.is_service_started(app)