From b1fa2bdae628d7b8195e4069282f3ee76e12136f Mon Sep 17 00:00:00 2001
From: Kyle McCormick <kmccormick@edx.org>
Date: Fri, 16 Apr 2021 14:00:04 -0400
Subject: [PATCH] refactor: make embargo app go through geoinfo API (#27350)

Consolidates all usage of geoip database within
geoinfo app.
---
 openedx/core/djangoapps/embargo/api.py        | 28 ++----------------
 openedx/core/djangoapps/geoinfo/api.py        | 29 +++++++++++++++++++
 openedx/core/djangoapps/geoinfo/middleware.py | 13 ++-------
 3 files changed, 34 insertions(+), 36 deletions(-)
 create mode 100644 openedx/core/djangoapps/geoinfo/api.py

diff --git a/openedx/core/djangoapps/embargo/api.py b/openedx/core/djangoapps/embargo/api.py
index e2b9066c2f..ba101f9b79 100644
--- a/openedx/core/djangoapps/embargo/api.py
+++ b/openedx/core/djangoapps/embargo/api.py
@@ -14,8 +14,8 @@ from ipware.ip import get_client_ip
 from rest_framework import status
 from rest_framework.response import Response
 
-import geoip2.database
 from common.djangoapps.student.auth import has_course_author_access
+from openedx.core.djangoapps.geoinfo.api import country_code_from_ip
 
 from .models import CountryAccessRule, RestrictedCourse
 
@@ -79,7 +79,7 @@ def check_course_access(course_key, user=None, ip_address=None, url=None):
     if ip_address is not None:
         # Retrieve the country code from the IP address
         # and check it against the allowed countries list for a course
-        user_country_from_ip = _country_code_from_ip(ip_address)
+        user_country_from_ip = country_code_from_ip(ip_address)
 
         if not CountryAccessRule.check_country_access(course_key, user_country_from_ip):
             log.info(
@@ -159,30 +159,6 @@ def _get_user_country_from_profile(user):
     return profile_country
 
 
-def _country_code_from_ip(ip_addr):
-    """
-    Return the country code associated with an IP address.
-    Handles both IPv4 and IPv6 addresses.
-
-    Args:
-        ip_addr (str): The IP address to look up.
-
-    Returns:
-        str: A 2-letter country code.
-
-    """
-    reader = geoip2.database.Reader(settings.GEOIP_PATH)
-
-    try:
-        response = reader.country(ip_addr)
-        # pylint: disable=no-member
-        country_code = response.country.iso_code
-    except geoip2.errors.AddressNotFoundError:
-        country_code = ""
-    reader.close()
-    return country_code
-
-
 def get_embargo_response(request, course_id, user):
     """
     Check whether any country access rules block the user from enrollment.
diff --git a/openedx/core/djangoapps/geoinfo/api.py b/openedx/core/djangoapps/geoinfo/api.py
new file mode 100644
index 0000000000..9445b56fb9
--- /dev/null
+++ b/openedx/core/djangoapps/geoinfo/api.py
@@ -0,0 +1,29 @@
+"""
+Simple Python API to identify the country of origin of page requests.
+"""
+
+import geoip2.database
+from django.conf import settings
+
+
+def country_code_from_ip(ip_addr: str) -> str:
+    """
+    Return the country code associated with an IP address.
+    Handles both IPv4 and IPv6 addresses.
+
+    Args:
+        ip_addr: The IP address to look up.
+
+    Returns:
+        A 2-letter country code,
+        or an empty string if lookup failed.
+    """
+    reader = geoip2.database.Reader(settings.GEOIP_PATH)
+    try:
+        response = reader.country(ip_addr)
+        # pylint: disable=no-member
+        country_code = response.country.iso_code
+    except geoip2.errors.AddressNotFoundError:
+        country_code = ""
+    reader.close()
+    return country_code
diff --git a/openedx/core/djangoapps/geoinfo/middleware.py b/openedx/core/djangoapps/geoinfo/middleware.py
index 1bd556bfba..9b9df817e2 100644
--- a/openedx/core/djangoapps/geoinfo/middleware.py
+++ b/openedx/core/djangoapps/geoinfo/middleware.py
@@ -10,13 +10,13 @@ decorator `django.utils.decorators.decorator_from_middleware(middleware_class)`
 
 """
 import logging
-import geoip2.database
 
-from django.conf import settings
 from django.utils.deprecation import MiddlewareMixin
 from ipware.ip import get_client_ip
 from ipware.utils import is_public_ip
 
+from .api import country_code_from_ip
+
 log = logging.getLogger(__name__)
 
 
@@ -37,14 +37,7 @@ class CountryMiddleware(MiddlewareMixin):
             del request.session['ip_address']
             del request.session['country_code']
         elif new_ip_address != old_ip_address and is_public_ip(new_ip_address):
-            reader = geoip2.database.Reader(settings.GEOIP_PATH)
-            try:
-                response = reader.country(new_ip_address)
-                country_code = response.country.iso_code
-            except geoip2.errors.AddressNotFoundError:
-                country_code = ""
-
+            country_code = country_code_from_ip(new_ip_address)
             request.session['country_code'] = country_code
             request.session['ip_address'] = new_ip_address
             log.debug('Country code for IP: %s is set to %s', new_ip_address, country_code)
-            reader.close()