Fetching/Requests - Fixing user agent header overrides per-watch of global settings (#2409)

changedetectionio/content_fetchers/base.py

@@ -28,7 +28,7 @@ def manage_user_agent(headers, current_ua=''):
     :return:
     """
     # Ask it what the user agent is, if its obviously ChromeHeadless, switch it to the default
-    ua_in_custom_headers = next((v for k, v in headers.items() if k.lower() == "user-agent"), None)
+    ua_in_custom_headers = headers.get('User-Agent')
     if ua_in_custom_headers:
         return ua_in_custom_headers
 

changedetectionio/content_fetchers/puppeteer.py

@@ -115,12 +115,11 @@ class fetcher(Fetcher):
 
         # This user agent is similar to what was used when tweaking the evasions in inject_evasions_into_page(..)
         user_agent = None
-        if request_headers:
-            user_agent = next((value for key, value in request_headers.items() if key.lower().strip() == 'user-agent'), None)
-            if user_agent:
-                await self.page.setUserAgent(user_agent)
+        if request_headers and request_headers.get('User-Agent'):
+            # Request_headers should now be CaaseInsensitiveDict
             # Remove it so it's not sent again with headers after
-                [request_headers.pop(key) for key in list(request_headers) if key.lower().strip() == 'user-agent'.lower().strip()]
+            user_agent = request_headers.pop('User-Agent').strip()
+            await self.page.setUserAgent(user_agent)
 
         if not user_agent:
             # Attempt to strip 'HeadlessChrome' etc

changedetectionio/processors/__init__.py

@@ -1,10 +1,10 @@
 from abc import abstractmethod
-import os
-import hashlib
-import re
-from copy import deepcopy
 from changedetectionio.strtobool import strtobool
+from copy import deepcopy
 from loguru import logger
+import hashlib
+import os
+import re
 
 class difference_detection_processor():
 
@@ -21,7 +21,7 @@ class difference_detection_processor():
         self.watch = deepcopy(self.datastore.data['watching'].get(watch_uuid))
 
     def call_browser(self):
-
+        from requests.structures import CaseInsensitiveDict
         # Protect against file:// access
         if re.search(r'^file://', self.watch.get('url', '').strip(), re.IGNORECASE):
             if not strtobool(os.getenv('ALLOW_FILE_URI', 'false')):
@@ -93,14 +93,16 @@ class difference_detection_processor():
             self.fetcher.browser_steps_screenshot_path = os.path.join(self.datastore.datastore_path, self.watch.get('uuid'))
 
         # Tweak the base config with the per-watch ones
-        request_headers = self.watch.get('headers', [])
-        request_headers.update(self.datastore.get_all_base_headers())
-        request_headers.update(self.datastore.get_all_headers_in_textfile_for_watch(uuid=self.watch.get('uuid')))
+        request_headers = CaseInsensitiveDict()
 
         ua = self.datastore.data['settings']['requests'].get('default_ua')
         if ua and ua.get(prefer_fetch_backend):
             request_headers.update({'User-Agent': ua.get(prefer_fetch_backend)})
 
+        request_headers.update(self.watch.get('headers', {}))
+        request_headers.update(self.datastore.get_all_base_headers())
+        request_headers.update(self.datastore.get_all_headers_in_textfile_for_watch(uuid=self.watch.get('uuid')))
+
         # https://github.com/psf/requests/issues/4525
         # Requests doesnt yet support brotli encoding, so don't put 'br' here, be totally sure that the user cannot
         # do this by accident.

changedetectionio/tests/test_request.py

@@ -253,6 +253,62 @@ def test_method_in_request(client, live_server):
     res = client.get(url_for("form_delete", uuid="all"), follow_redirects=True)
     assert b'Deleted' in res.data
 
+# Re #2408 - user-agent override test, also should handle case-insensitive header deduplication
+def test_ua_global_override(client, live_server):
+    # live_server_setup(live_server)
+    test_url = url_for('test_headers', _external=True)
+
+    res = client.post(
+        url_for("settings_page"),
+        data={
+            "application-fetch_backend": "html_requests",
+            "application-minutes_between_check": 180,
+            "requests-default_ua-html_requests": "html-requests-user-agent"
+        },
+        follow_redirects=True
+    )
+    assert b'Settings updated' in res.data
+
+    res = client.post(
+        url_for("import_page"),
+        data={"urls": test_url},
+        follow_redirects=True
+    )
+    assert b"1 Imported" in res.data
+
+    wait_for_all_checks(client)
+    res = client.get(
+        url_for("preview_page", uuid="first"),
+        follow_redirects=True
+    )
+
+    assert b"html-requests-user-agent" in res.data
+    # default user-agent should have shown by now
+    # now add a custom one in the headers
+
+
+    # Add some headers to a request
+    res = client.post(
+        url_for("edit_page", uuid="first"),
+        data={
+            "url": test_url,
+            "tags": "testtag",
+            "fetch_backend": 'html_requests',
+            # Important - also test case-insensitive
+            "headers": "User-AGent: agent-from-watch"},
+        follow_redirects=True
+    )
+    assert b"Updated watch." in res.data
+    wait_for_all_checks(client)
+    res = client.get(
+        url_for("preview_page", uuid="first"),
+        follow_redirects=True
+    )
+    assert b"agent-from-watch" in res.data
+    assert b"html-requests-user-agent" not in res.data
+    res = client.get(url_for("form_delete", uuid="all"), follow_redirects=True)
+    assert b'Deleted' in res.data
+
 def test_headers_textfile_in_request(client, live_server):
     #live_server_setup(live_server)
     # Add our URL to the import page
@@ -333,7 +389,7 @@ def test_headers_textfile_in_request(client, live_server):
     # Not needed anymore
     os.unlink('test-datastore/headers.txt')
     os.unlink('test-datastore/headers-testtag.txt')
-    os.unlink('test-datastore/' + extract_UUID_from_client(client) + '/headers.txt')
+
     # The service should echo back the request verb
     res = client.get(
         url_for("preview_page", uuid="first"),