Replace curl by requests

Replace the curl utility by the python requests library to avoid another
host-dependency.

tests/test_nginx.py

@@ -1,7 +1,8 @@
 """This module contains the tests for the nginx container, the image with nginx pre-installed.
 """
 from bci_tester.data import NGINX_CONTAINER
-
+import requests
+import time
 
 CONTAINER_IMAGES = (NGINX_CONTAINER,)
 
@@ -10,6 +11,11 @@ def test_nginx_welcome_page(auto_container, host):
     """test that the default welcome page is served by the container."""
     host_port = auto_container.forwarded_ports[0].host_port
 
-    assert "Welcome to nginx" in host.check_output(
-        f"curl -sf --retry 5 --retry-connrefused http://localhost:{host_port}/"
-    )
+    # Retry 5 times with quadratic backoff delay
+    retries = 5
+    for i in range(retries):
+        resp = requests.get(f"http://localhost:{host_port}/", timeout=30)
+        if resp.status_code == 200 and "Welcome to nginx" in resp.text:
+            return
+        time.Sleep(i * i)
+    assert False, "invalid nginx response"

tox.ini

@@ -11,6 +11,7 @@ deps =
     dataclasses ; python_version < "3.7"
     pytest-rerunfailures
     typing_extensions
+    requests
     git+https://github.com/dcermak/pytest_container
     doc: Sphinx