tests: refactor the config test to use a simple python codebase instead

This should also make it possible to run the tests locally on an ARM machine.

tests/apps/config/web.py

@@ -0,0 +1,37 @@
+import http.server
+import json
+import os
+import sys
+
+
+class GetHandler(http.server.BaseHTTPRequestHandler):
+    def do_GET(self):
+        self.send_response(200)
+        self.send_header("Content-Type", "text/plain; charset=utf-8")
+        self.end_headers()
+
+        if self.path == '/':
+            self.wfile.write("python/http.server".encode("utf-8"))
+        elif self.path == '/conftest':
+            value = os.getenv("CONFTEST", "")
+            self.wfile.write(value.encode("utf-8"))
+        elif self.path == '/hello':
+            value = os.getenv("HELLO", "")
+            self.wfile.write(value.encode("utf-8"))
+        else:
+            data = json.dumps(dict(os.environ), sort_keys=True, indent=4)
+            self.wfile.write(data.encode("utf-8"))
+
+
+if __name__ == "__main__":
+    if os.getenv("FAIL_ON_STARTUP") == "true":
+        print("Failing on startup due to FAIL_ON_STARTUP=true")
+        sys.exit(1)
+
+    for arg in sys.argv:
+        print(f"Arg: {arg}")
+
+    port = int(os.getenv("PORT", 5000))
+    server = http.server.HTTPServer(("0.0.0.0", port), GetHandler)
+    print("Listening on port {0}".format(port))
+    server.serve_forever()