fix(linter): redirect linter if on prod to test (#4856)

When people attempt the /linter-findings endpoint they are getting
403'ed. A better user journey is to be redirected to the test instance.

Author: jess-lowe

gcp/website/frontend_handlers.py

@@ -220,6 +220,8 @@ def docs():
 
 @blueprint.route('/linter', strict_slashes=False)
 def linter():
+  if request.host_url == 'osv.dev':
+    return redirect(request.url.replace('osv.dev', 'test.osv.dev'), code=302)
   return render_template('linter.html')
 
 

gcp/website/linter_api.py

@@ -15,7 +15,7 @@
 
 import json
 import logging
-from flask import Blueprint, abort, jsonify
+from flask import Blueprint, abort, jsonify, redirect, request
 from google.cloud import storage
 
 blueprint = Blueprint('linter_api', __name__, url_prefix='/linter-findings')
@@ -25,6 +25,19 @@
 LINTER_PREFIX = 'linter-result/'
 
 
+@blueprint.before_request
+def redirect_to_test():
+  """Redirect requests from production to test site."""
+  if request.host == 'osv.dev':
+    return redirect(request.url.replace('osv.dev', 'test.osv.dev'), code=302)
+
+  if request.host == 'api.osv.dev':
+    return redirect(
+        request.url.replace('api.osv.dev', 'api.test.osv.dev'), code=302)
+
+  return None
+
+
 def _get_storage_client():
   """Get storage client."""
   return storage.Client()