Do not crash hard if a reload's results are indeterminate due to possible DNS config issues. by: Conrad, Giles

Author: gpjt

pythonanywhere/api.py

@@ -130,6 +130,18 @@ def reload(self):
         url = get_api_endpoint().format(username=getpass.getuser(), flavor="webapps") + self.domain + "/reload/"
         response = call_api(url, "post")
         if not response.ok:
+            if response.status_code == 409 and response.json()["error"] == "cname_error":
+                print(
+                    snakesay(
+                        dedent("""
+                            Could not find a CNAME for your website.  If you're using an A record,
+                            CloudFlare, or some other way of pointing your domain at PythonAnywhere
+                            then that should not be a problem.  If you're not, you should double-check
+                            your DNS setup.
+                        """)
+                    )
+                )
+                return
             raise Exception(
                 "POST to reload webapp via API failed, got {response}:{response_text}".format(
                     response=response, response_text=response.text

tests/test_api.py

@@ -236,7 +236,7 @@ def test_does_post_to_reload_url(self, api_responses, api_token):
         assert post.request.body is None
         assert post.request.headers["Authorization"] == "Token {api_token}".format(api_token=api_token)
 
-    def test_raises_if_post_does_not_20x(self, api_responses, api_token):
+    def test_raises_if_post_does_not_20x_that_is_not_a_cname_error(self, api_responses, api_token):
         expected_url = (
             get_api_endpoint().format(username=getpass.getuser(), flavor="webapps") + "mydomain.com/reload/"
         )
@@ -248,6 +248,15 @@ def test_raises_if_post_does_not_20x(self, api_responses, api_token):
         assert "POST to reload webapp via API failed" in str(e.value)
         assert "nope" in str(e.value)
 
+    def test_does_not_raise_if_post_responds_with_a_cname_error(self, api_responses, api_token):
+        expected_url = (
+            get_api_endpoint().format(username=getpass.getuser(), flavor="webapps") + "mydomain.com/reload/"
+        )
+        api_responses.add(responses.POST, expected_url, status=409, json={"status": "error", "error": "cname_error"})
+
+        ## Should not raise
+        Webapp("mydomain.com").reload()
+
 
 class TestSetWebappSSL:
     def test_does_post_to_ssl_url(self, api_responses, api_token):