From 3a736eefa20cc294a022e4571fda3715ed9e7c3c Mon Sep 17 00:00:00 2001
From: Eric Herrera <eric.herrera@edunext.co>
Date: Sun, 1 Aug 2021 09:19:23 -0500
Subject: [PATCH 1/5] feat: Codejail as external service (optional)

Add codejail service settings (endpoint and feature flag).
Add conditional to allow running codejail using a REST API service when flag is enabled.
---
 common/lib/capa/capa/safe_exec/safe_exec.py | 78 +++++++++++++++------
 lms/envs/common.py                          | 15 ++++
 2 files changed, 73 insertions(+), 20 deletions(-)

diff --git a/common/lib/capa/capa/safe_exec/safe_exec.py b/common/lib/capa/capa/safe_exec/safe_exec.py
index c71854f917..2012d8544f 100644
--- a/common/lib/capa/capa/safe_exec/safe_exec.py
+++ b/common/lib/capa/capa/safe_exec/safe_exec.py
@@ -2,10 +2,13 @@
 
 
 import hashlib
+import requests
+import json
 
 from codejail.safe_exec import SafeExecException, json_safe
 from codejail.safe_exec import not_safe_exec as codejail_not_safe_exec
 from codejail.safe_exec import safe_exec as codejail_safe_exec
+from django.conf import settings
 from edx_django_utils.monitoring import function_trace
 import six
 from six import text_type
@@ -143,28 +146,63 @@ def safe_exec(
     # Create the complete code we'll run.
     code_prolog = CODE_PROLOG % random_seed
 
-    # Decide which code executor to use.
-    if unsafely:
-        exec_fn = codejail_not_safe_exec
+    if settings.FEATURES.get('ENABLE_CODEJAIL_REST_SERVICE', False):
+        try:
+            codejail_service_endpoint = "".join([
+                settings.CODE_JAIL_REST_SERVICE_HOST,
+                "/api/v0/code-exec"
+                ])
+            data = {
+                "code": code_prolog + LAZY_IMPORTS + code,
+                "globals_dict": globals_dict,
+                "python_path": python_path,
+                "limit_overrides_context": limit_overrides_context,
+                "slug": slug,
+                "unsafely": unsafely
+            }
+            datajson = json.dumps(data)
+            response = requests.request(
+                "POST",
+                codejail_service_endpoint,
+                files=extra_files,
+                data={'payload': datajson}
+            )
+            response_json = response.json()
+            emsg = response_json["emsg"]
+            if emsg:
+                exception_msg = ". ".join([
+                        emsg,
+                        "For more information check Codejail Service logs."
+                    ])
+                
+                exception = SafeExecException(emsg)
+            globals_dict.update(response_json["globals_dict"])
+        except Exception as e:
+            raise e
+            emsg = None
     else:
-        exec_fn = codejail_safe_exec
+        # Decide which code executor to use.
+        if unsafely:
+            exec_fn = codejail_not_safe_exec
+        else:
+            exec_fn = codejail_safe_exec
 
-    # Run the code!  Results are side effects in globals_dict.
-    try:
-        exec_fn(
-            code_prolog + LAZY_IMPORTS + code,
-            globals_dict,
-            python_path=python_path,
-            extra_files=extra_files,
-            limit_overrides_context=limit_overrides_context,
-            slug=slug,
-        )
-    except SafeExecException as e:
-        # Saving SafeExecException e in exception to be used later.
-        exception = e
-        emsg = text_type(e)
-    else:
-        emsg = None
+        # Run the code!  Results are side effects in globals_dict.
+        try:
+            exec_fn(
+                code_prolog + LAZY_IMPORTS + code,
+                globals_dict,
+                python_path=python_path,
+                extra_files=extra_files,
+                limit_overrides_context=limit_overrides_context,
+                slug=slug,
+            )
+        except SafeExecException as e:
+            # Saving SafeExecException e in exception to be used later.
+            exception = e
+            emsg = text_type(e)
+        else:
+            emsg = None
 
     # Put the result back in the cache.  This is complicated by the fact that
     # the globals dict might not be entirely serializable.
diff --git a/lms/envs/common.py b/lms/envs/common.py
index 0bb174d0ec..12ad10d314 100644
--- a/lms/envs/common.py
+++ b/lms/envs/common.py
@@ -948,6 +948,18 @@ FEATURES = {
     # .. toggle_target_removal_date: 2021-10-01
     # .. toggle_tickets: 'https://openedx.atlassian.net/browse/MICROBA-1405'
     'ENABLE_V2_CERT_DISPLAY_SETTINGS': False,
+    
+    # .. toggle_name: ENABLE_CODEJAIL_REST_SERVICE
+    # .. toggle_implementation: DjangoSetting
+    # .. toggle_default: False
+    # .. toggle_description: Set this to True if you want to run Codejail code using
+    #   a separate VM or container and communicate with edx-platform using REST API.
+    # .. toggle_use_cases: tutor
+    # .. toggle_creation_date: 2021-08-19
+    # .. toggle_target_removal_date: None
+    # .. toggle_warnings: 
+    # .. toggle_tickets: 
+    'ENABLE_CODEJAIL_REST_SERVICE': False,
 }
 
 # Specifies extra XBlock fields that should available when requested via the Course Blocks API
@@ -1629,6 +1641,9 @@ CODE_JAIL = {
 #   ]
 COURSES_WITH_UNSAFE_CODE = []
 
+# Cojail REST service
+CODE_JAIL_REST_SERVICE_HOST = 'http://127.0.0.1:8550'
+
 ############################### DJANGO BUILT-INS ###############################
 # Change DEBUG in your environment settings files, not here
 DEBUG = False

From d672d309e80ed2f0b2924138c42ca8351177caa7 Mon Sep 17 00:00:00 2001
From: Eric Herrera <eric.herrera@edunext.co>
Date: Sun, 1 Aug 2021 09:22:31 -0500
Subject: [PATCH 2/5] fix: Improve and fix codejail service integration

Address recommendations and fixes discussed in PR.
Use similar structure to notes app.
Fix errors detected in tests.
---
 common/lib/capa/capa/safe_exec/exceptions.py | 24 +++++
 common/lib/capa/capa/safe_exec/helpers.py    | 97 ++++++++++++++++++++
 common/lib/capa/capa/safe_exec/safe_exec.py  | 50 +++-------
 lms/envs/common.py                           | 11 ++-
 4 files changed, 141 insertions(+), 41 deletions(-)
 create mode 100644 common/lib/capa/capa/safe_exec/exceptions.py
 create mode 100644 common/lib/capa/capa/safe_exec/helpers.py

diff --git a/common/lib/capa/capa/safe_exec/exceptions.py b/common/lib/capa/capa/safe_exec/exceptions.py
new file mode 100644
index 0000000000..c6cb78c8f8
--- /dev/null
+++ b/common/lib/capa/capa/safe_exec/exceptions.py
@@ -0,0 +1,24 @@
+"""
+Exceptions related to safe exec.
+"""
+
+
+class CodejailServiceParseError(Exception):
+    """
+    An exception that is raised whenever we have issues with data parsing.
+    """
+    pass  # lint-amnesty, pylint: disable=unnecessary-pass
+
+
+class CodejailServiceStatusError(Exception):
+    """
+    An exception that is raised whenever Codejail service response status is different to 200.
+    """
+    pass  # lint-amnesty, pylint: disable=unnecessary-pass
+
+
+class CodejailServiceUnavailable(Exception):
+    """
+    An exception that is raised whenever Codejail service is unavailable.
+    """
+    pass  # lint-amnesty, pylint: disable=unnecessary-pass
diff --git a/common/lib/capa/capa/safe_exec/helpers.py b/common/lib/capa/capa/safe_exec/helpers.py
new file mode 100644
index 0000000000..76c62e4259
--- /dev/null
+++ b/common/lib/capa/capa/safe_exec/helpers.py
@@ -0,0 +1,97 @@
+"""
+Helper methods related to safe exec.
+"""
+
+import requests
+import json
+import logging
+
+from codejail.safe_exec import SafeExecException
+from django.conf import settings
+from django.utils.translation import ugettext as _
+from edx_toggles.toggles import SettingDictToggle
+from requests.exceptions import RequestException, HTTPError
+from simplejson import JSONDecodeError
+
+from .exceptions import CodejailServiceParseError, CodejailServiceStatusError, CodejailServiceUnavailable
+
+log = logging.getLogger(__name__)
+
+# .. toggle_name: ENABLE_CODEJAIL_REST_SERVICE
+# .. toggle_implementation: DjangoSetting
+# .. toggle_default: False
+# .. toggle_description: Set this to True if you want to run Codejail code using
+#   a separate VM or container and communicate with edx-platform using REST API.
+# .. toggle_use_cases: open_edx
+# .. toggle_creation_date: 2021-08-19
+# .. toggle_target_removal_date: None
+# .. toggle_warnings:
+# .. toggle_tickets:
+ENABLE_CODEJAIL_REST_SERVICE = SettingDictToggle(
+    "FEATURES", "ENABLE_CODEJAIL_REST_SERVICE", default=False, module_name=__name__
+)
+
+
+def is_codejail_rest_service_enabled():
+    return ENABLE_CODEJAIL_REST_SERVICE.is_enabled()
+
+
+def get_codejail_rest_service_endpoint():
+    return "".join([
+        settings.CODE_JAIL_REST_SERVICE_HOST,
+        "/api/v0/code-exec"])
+
+
+def send_safe_exec_request(data, extra_files):
+    """
+    Sends a request to a codejail api service forwarding required code and files.
+    Arguments:
+        data: Dict containing code and othe parameters
+            required for jailed code execution.
+        extra_files: python_lib.zip file containing extra files
+            required by the codejail execution.
+    Returns:
+        Response received from codejsail api service
+    """
+    globals_dict = data["globals_dict"]
+
+    codejail_service_endpoint = get_codejail_rest_service_endpoint()
+    payload = json.dumps(data)
+
+    try:
+        response = requests.post(
+            codejail_service_endpoint,
+            files=extra_files,
+            data={'payload': payload},
+            timeout=(settings.CODE_JAIL_REST_SERVICE_CONNECT_TIMEOUT, settings.CODE_JAIL_REST_SERVICE_READ_TIMEOUT)
+        )
+
+    except RequestException:
+        log.error("Failed to connect to codejail api service: url=%s, params=%s",
+                  codejail_service_endpoint, str(payload))
+        raise CodejailServiceUnavailable(_("Codejail API Service is unavailable. Please try again in a few minutes."))  # lint-amnesty, pylint: disable=raise-missing-from
+
+    try:
+        response.raise_for_status()
+    except HTTPError:
+        raise CodejailServiceStatusError(_("Codejail API Service invalid response."))  # lint-amnesty, pylint: disable=raise-missing-from
+
+    try:
+        response_json = response.json()
+    except JSONDecodeError:
+        log.error("Invalid JSON response received from codejail api service: Response_Content=%s", response.content)
+        raise CodejailServiceParseError(_("Invalid JSON response received from codejail api service."))  # lint-amnesty, pylint: disable=raise-missing-from
+
+    emsg = response_json.get("emsg")
+    exception = None
+
+    if emsg:
+        exception_msg = ". ".join([
+            emsg,
+            "For more information check Codejail Service logs."])
+
+        exception = SafeExecException(exception_msg)
+
+    globals_dict.update(response_json.get("globals_dict"))
+
+    return emsg, exception
diff --git a/common/lib/capa/capa/safe_exec/safe_exec.py b/common/lib/capa/capa/safe_exec/safe_exec.py
index 2012d8544f..4b5d36c74d 100644
--- a/common/lib/capa/capa/safe_exec/safe_exec.py
+++ b/common/lib/capa/capa/safe_exec/safe_exec.py
@@ -2,18 +2,16 @@
 
 
 import hashlib
-import requests
-import json
 
 from codejail.safe_exec import SafeExecException, json_safe
 from codejail.safe_exec import not_safe_exec as codejail_not_safe_exec
 from codejail.safe_exec import safe_exec as codejail_safe_exec
-from django.conf import settings
 from edx_django_utils.monitoring import function_trace
 import six
 from six import text_type
 
 from . import lazymod
+from .helpers import is_codejail_rest_service_enabled, send_safe_exec_request
 
 # Establish the Python environment for Capa.
 # Capa assumes float-friendly division always.
@@ -146,40 +144,18 @@ def safe_exec(
     # Create the complete code we'll run.
     code_prolog = CODE_PROLOG % random_seed
 
-    if settings.FEATURES.get('ENABLE_CODEJAIL_REST_SERVICE', False):
-        try:
-            codejail_service_endpoint = "".join([
-                settings.CODE_JAIL_REST_SERVICE_HOST,
-                "/api/v0/code-exec"
-                ])
-            data = {
-                "code": code_prolog + LAZY_IMPORTS + code,
-                "globals_dict": globals_dict,
-                "python_path": python_path,
-                "limit_overrides_context": limit_overrides_context,
-                "slug": slug,
-                "unsafely": unsafely
-            }
-            datajson = json.dumps(data)
-            response = requests.request(
-                "POST",
-                codejail_service_endpoint,
-                files=extra_files,
-                data={'payload': datajson}
-            )
-            response_json = response.json()
-            emsg = response_json["emsg"]
-            if emsg:
-                exception_msg = ". ".join([
-                        emsg,
-                        "For more information check Codejail Service logs."
-                    ])
-                
-                exception = SafeExecException(emsg)
-            globals_dict.update(response_json["globals_dict"])
-        except Exception as e:
-            raise e
-            emsg = None
+    if is_codejail_rest_service_enabled():
+        data = {
+            "code": code_prolog + LAZY_IMPORTS + code,
+            "globals_dict": globals_dict,
+            "python_path": python_path,
+            "limit_overrides_context": limit_overrides_context,
+            "slug": slug,
+            "unsafely": unsafely
+        }
+
+        emsg, exception = send_safe_exec_request(data, extra_files)
+
     else:
         # Decide which code executor to use.
         if unsafely:
diff --git a/lms/envs/common.py b/lms/envs/common.py
index 12ad10d314..15c81ea58c 100644
--- a/lms/envs/common.py
+++ b/lms/envs/common.py
@@ -948,17 +948,17 @@ FEATURES = {
     # .. toggle_target_removal_date: 2021-10-01
     # .. toggle_tickets: 'https://openedx.atlassian.net/browse/MICROBA-1405'
     'ENABLE_V2_CERT_DISPLAY_SETTINGS': False,
-    
+
     # .. toggle_name: ENABLE_CODEJAIL_REST_SERVICE
     # .. toggle_implementation: DjangoSetting
     # .. toggle_default: False
     # .. toggle_description: Set this to True if you want to run Codejail code using
     #   a separate VM or container and communicate with edx-platform using REST API.
-    # .. toggle_use_cases: tutor
+    # .. toggle_use_cases: open_edx
     # .. toggle_creation_date: 2021-08-19
     # .. toggle_target_removal_date: None
-    # .. toggle_warnings: 
-    # .. toggle_tickets: 
+    # .. toggle_warnings:
+    # .. toggle_tickets:
     'ENABLE_CODEJAIL_REST_SERVICE': False,
 }
 
@@ -1643,6 +1643,9 @@ COURSES_WITH_UNSAFE_CODE = []
 
 # Cojail REST service
 CODE_JAIL_REST_SERVICE_HOST = 'http://127.0.0.1:8550'
+CODE_JAIL_REST_SERVICE_CONNECT_TIMEOUT = 0.5  # time in seconds
+CODE_JAIL_REST_SERVICE_READ_TIMEOUT = 3.5  # time in seconds
+
 
 ############################### DJANGO BUILT-INS ###############################
 # Change DEBUG in your environment settings files, not here

From fc7104cde5fe260e0d2f5cadbd8c7ab66da66f7b Mon Sep 17 00:00:00 2001
From: Eric Herrera <eric.herrera@edunext.co>
Date: Mon, 4 Oct 2021 21:15:10 -0500
Subject: [PATCH 3/5] fix: Address PR comments

Address fixes recommended by @timmc-edx.
---
 common/lib/capa/capa/safe_exec/exceptions.py |  3 --
 common/lib/capa/capa/safe_exec/helpers.py    | 39 +++++++++-----------
 lms/envs/common.py                           | 12 ------
 3 files changed, 17 insertions(+), 37 deletions(-)

diff --git a/common/lib/capa/capa/safe_exec/exceptions.py b/common/lib/capa/capa/safe_exec/exceptions.py
index c6cb78c8f8..e3843d0617 100644
--- a/common/lib/capa/capa/safe_exec/exceptions.py
+++ b/common/lib/capa/capa/safe_exec/exceptions.py
@@ -7,18 +7,15 @@ class CodejailServiceParseError(Exception):
     """
     An exception that is raised whenever we have issues with data parsing.
     """
-    pass  # lint-amnesty, pylint: disable=unnecessary-pass
 
 
 class CodejailServiceStatusError(Exception):
     """
     An exception that is raised whenever Codejail service response status is different to 200.
     """
-    pass  # lint-amnesty, pylint: disable=unnecessary-pass
 
 
 class CodejailServiceUnavailable(Exception):
     """
     An exception that is raised whenever Codejail service is unavailable.
     """
-    pass  # lint-amnesty, pylint: disable=unnecessary-pass
diff --git a/common/lib/capa/capa/safe_exec/helpers.py b/common/lib/capa/capa/safe_exec/helpers.py
index 76c62e4259..42d567f3ab 100644
--- a/common/lib/capa/capa/safe_exec/helpers.py
+++ b/common/lib/capa/capa/safe_exec/helpers.py
@@ -9,7 +9,7 @@ import logging
 from codejail.safe_exec import SafeExecException
 from django.conf import settings
 from django.utils.translation import ugettext as _
-from edx_toggles.toggles import SettingDictToggle
+from edx_toggles.toggles import SettingToggle
 from requests.exceptions import RequestException, HTTPError
 from simplejson import JSONDecodeError
 
@@ -18,17 +18,14 @@ from .exceptions import CodejailServiceParseError, CodejailServiceStatusError, C
 log = logging.getLogger(__name__)
 
 # .. toggle_name: ENABLE_CODEJAIL_REST_SERVICE
-# .. toggle_implementation: DjangoSetting
+# .. toggle_implementation: SettingToggle
 # .. toggle_default: False
 # .. toggle_description: Set this to True if you want to run Codejail code using
 #   a separate VM or container and communicate with edx-platform using REST API.
 # .. toggle_use_cases: open_edx
 # .. toggle_creation_date: 2021-08-19
-# .. toggle_target_removal_date: None
-# .. toggle_warnings:
-# .. toggle_tickets:
-ENABLE_CODEJAIL_REST_SERVICE = SettingDictToggle(
-    "FEATURES", "ENABLE_CODEJAIL_REST_SERVICE", default=False, module_name=__name__
+ENABLE_CODEJAIL_REST_SERVICE = SettingToggle(
+    "ENABLE_CODEJAIL_REST_SERVICE", default=False, module_name=__name__
 )
 
 
@@ -37,21 +34,19 @@ def is_codejail_rest_service_enabled():
 
 
 def get_codejail_rest_service_endpoint():
-    return "".join([
-        settings.CODE_JAIL_REST_SERVICE_HOST,
-        "/api/v0/code-exec"])
+    return f"{settings.CODE_JAIL_REST_SERVICE_HOST}/api/v0/code-exec"
 
 
 def send_safe_exec_request(data, extra_files):
     """
     Sends a request to a codejail api service forwarding required code and files.
     Arguments:
-        data: Dict containing code and othe parameters
+        data: Dict containing code and other parameters
             required for jailed code execution.
         extra_files: python_lib.zip file containing extra files
             required by the codejail execution.
     Returns:
-        Response received from codejsail api service
+        Response received from codejail api service
     """
     globals_dict = data["globals_dict"]
 
@@ -66,30 +61,30 @@ def send_safe_exec_request(data, extra_files):
             timeout=(settings.CODE_JAIL_REST_SERVICE_CONNECT_TIMEOUT, settings.CODE_JAIL_REST_SERVICE_READ_TIMEOUT)
         )
 
-    except RequestException:
+    except RequestException as err:
         log.error("Failed to connect to codejail api service: url=%s, params=%s",
                   codejail_service_endpoint, str(payload))
-        raise CodejailServiceUnavailable(_("Codejail API Service is unavailable. Please try again in a few minutes."))  # lint-amnesty, pylint: disable=raise-missing-from
+        raise CodejailServiceUnavailable(_(
+            "Codejail API Service is unavailable. "
+            "Please try again in a few minutes."
+        )) from err
 
     try:
         response.raise_for_status()
-    except HTTPError:
-        raise CodejailServiceStatusError(_("Codejail API Service invalid response."))  # lint-amnesty, pylint: disable=raise-missing-from
+    except HTTPError as err:
+        raise CodejailServiceStatusError(_("Codejail API Service invalid response.")) from err
 
     try:
         response_json = response.json()
-    except JSONDecodeError:
+    except JSONDecodeError as err:
         log.error("Invalid JSON response received from codejail api service: Response_Content=%s", response.content)
-        raise CodejailServiceParseError(_("Invalid JSON response received from codejail api service."))  # lint-amnesty, pylint: disable=raise-missing-from
+        raise CodejailServiceParseError(_("Invalid JSON response received from codejail api service.")) from err
 
     emsg = response_json.get("emsg")
     exception = None
 
     if emsg:
-        exception_msg = ". ".join([
-            emsg,
-            "For more information check Codejail Service logs."])
-
+        exception_msg = f"{emsg}. For more information check Codejail Service logs."
         exception = SafeExecException(exception_msg)
 
     globals_dict.update(response_json.get("globals_dict"))
diff --git a/lms/envs/common.py b/lms/envs/common.py
index 15c81ea58c..40c0343be0 100644
--- a/lms/envs/common.py
+++ b/lms/envs/common.py
@@ -948,18 +948,6 @@ FEATURES = {
     # .. toggle_target_removal_date: 2021-10-01
     # .. toggle_tickets: 'https://openedx.atlassian.net/browse/MICROBA-1405'
     'ENABLE_V2_CERT_DISPLAY_SETTINGS': False,
-
-    # .. toggle_name: ENABLE_CODEJAIL_REST_SERVICE
-    # .. toggle_implementation: DjangoSetting
-    # .. toggle_default: False
-    # .. toggle_description: Set this to True if you want to run Codejail code using
-    #   a separate VM or container and communicate with edx-platform using REST API.
-    # .. toggle_use_cases: open_edx
-    # .. toggle_creation_date: 2021-08-19
-    # .. toggle_target_removal_date: None
-    # .. toggle_warnings:
-    # .. toggle_tickets:
-    'ENABLE_CODEJAIL_REST_SERVICE': False,
 }
 
 # Specifies extra XBlock fields that should available when requested via the Course Blocks API

From fe6882819a692cb90ee7a9a2c738d96a3de81a48 Mon Sep 17 00:00:00 2001
From: Eric Herrera <eric.herrera@edunext.co>
Date: Thu, 7 Oct 2021 10:42:20 -0500
Subject: [PATCH 4/5] fix: Address more PR comments

Address @felipemonotoya recommendations related to add versioning to safe_exec_remote functions.
---
 cms/envs/common.py                            | 22 +++++++++++++++++++
 .../safe_exec/{helpers.py => remote_exec.py}  | 21 +++++++++++++++---
 common/lib/capa/capa/safe_exec/safe_exec.py   |  7 +++---
 lms/envs/common.py                            | 17 ++++++++++++++
 4 files changed, 61 insertions(+), 6 deletions(-)
 rename common/lib/capa/capa/safe_exec/{helpers.py => remote_exec.py} (78%)

diff --git a/cms/envs/common.py b/cms/envs/common.py
index 5036425d25..974e99370a 100644
--- a/cms/envs/common.py
+++ b/cms/envs/common.py
@@ -1000,6 +1000,28 @@ CODE_JAIL = {
 
 COURSES_WITH_UNSAFE_CODE = []
 
+# Cojail REST service
+ENABLE_CODEJAIL_REST_SERVICE = False
+# .. setting_name: CODE_JAIL_REST_SERVICE_REMOTE_EXEC
+# .. setting_default: 'common.lib.capa.capa.safe_exec.remote_exec.send_safe_exec_request_v0'
+# .. setting_description: Set the python package.module.function that is reponsible of
+#   calling the remote service in charge of jailed code execution
+CODE_JAIL_REST_SERVICE_REMOTE_EXEC = 'common.lib.capa.capa.safe_exec.remote_exec.send_safe_exec_request_v0'
+# .. setting_name: CODE_JAIL_REST_SERVICE_HOST
+# .. setting_default: 'http://127.0.0.1:8550'
+# .. setting_description: Set the codejail remote service host
+CODE_JAIL_REST_SERVICE_HOST = 'http://127.0.0.1:8550'
+# .. setting_name: CODE_JAIL_REST_SERVICE_CONNECT_TIMEOUT
+# .. setting_default: 0.5
+# .. setting_description: Set the number of seconds CMS will wait to establish an internal
+#   connection to the codejail remote service.
+CODE_JAIL_REST_SERVICE_CONNECT_TIMEOUT = 0.5  # time in seconds
+# .. setting_name: CODE_JAIL_REST_SERVICE_READ_TIMEOUT
+# .. setting_default: 3.5
+# .. setting_description: Set the number of seconds CMS will wait for a response from the
+#   codejail remote service endpoint.
+CODE_JAIL_REST_SERVICE_READ_TIMEOUT = 3.5  # time in seconds
+
 ############################ DJANGO_BUILTINS ################################
 # Change DEBUG in your environment settings files, not here
 DEBUG = False
diff --git a/common/lib/capa/capa/safe_exec/helpers.py b/common/lib/capa/capa/safe_exec/remote_exec.py
similarity index 78%
rename from common/lib/capa/capa/safe_exec/helpers.py
rename to common/lib/capa/capa/safe_exec/remote_exec.py
index 42d567f3ab..7f13e0fbd3 100644
--- a/common/lib/capa/capa/safe_exec/helpers.py
+++ b/common/lib/capa/capa/safe_exec/remote_exec.py
@@ -10,6 +10,7 @@ from codejail.safe_exec import SafeExecException
 from django.conf import settings
 from django.utils.translation import ugettext as _
 from edx_toggles.toggles import SettingToggle
+from importlib import import_module
 from requests.exceptions import RequestException, HTTPError
 from simplejson import JSONDecodeError
 
@@ -33,22 +34,36 @@ def is_codejail_rest_service_enabled():
     return ENABLE_CODEJAIL_REST_SERVICE.is_enabled()
 
 
+def get_remote_exec(*args, **kwargs):
+    """Get remote exec function based on setting and executes it."""
+    remote_exec_function_name = settings.CODE_JAIL_REST_SERVICE_REMOTE_EXEC
+    try:
+        mod_name, func_name = remote_exec_function_name.rsplit('.', 1)
+        remote_exec_module = import_module(mod_name)
+        remote_exec_function = getattr(remote_exec_module, func_name)
+        if not remote_exec_function:
+            remote_exec_function = send_safe_exec_request_v0
+    except ModuleNotFoundError:
+        return send_safe_exec_request_v0(*args, **kwargs)
+    return remote_exec_function(*args, **kwargs)
+
+
 def get_codejail_rest_service_endpoint():
     return f"{settings.CODE_JAIL_REST_SERVICE_HOST}/api/v0/code-exec"
 
 
-def send_safe_exec_request(data, extra_files):
+def send_safe_exec_request_v0(data):
     """
     Sends a request to a codejail api service forwarding required code and files.
     Arguments:
         data: Dict containing code and other parameters
             required for jailed code execution.
-        extra_files: python_lib.zip file containing extra files
-            required by the codejail execution.
+            It also includes extra_files (python_lib.zip) required by the codejail execution.
     Returns:
         Response received from codejail api service
     """
     globals_dict = data["globals_dict"]
+    extra_files = data.pop("extra_files")
 
     codejail_service_endpoint = get_codejail_rest_service_endpoint()
     payload = json.dumps(data)
diff --git a/common/lib/capa/capa/safe_exec/safe_exec.py b/common/lib/capa/capa/safe_exec/safe_exec.py
index 4b5d36c74d..e08e58d488 100644
--- a/common/lib/capa/capa/safe_exec/safe_exec.py
+++ b/common/lib/capa/capa/safe_exec/safe_exec.py
@@ -11,7 +11,7 @@ import six
 from six import text_type
 
 from . import lazymod
-from .helpers import is_codejail_rest_service_enabled, send_safe_exec_request
+from .remote_exec import is_codejail_rest_service_enabled, get_remote_exec
 
 # Establish the Python environment for Capa.
 # Capa assumes float-friendly division always.
@@ -151,10 +151,11 @@ def safe_exec(
             "python_path": python_path,
             "limit_overrides_context": limit_overrides_context,
             "slug": slug,
-            "unsafely": unsafely
+            "unsafely": unsafely,
+            "extra_files": extra_files,
         }
 
-        emsg, exception = send_safe_exec_request(data, extra_files)
+        emsg, exception = get_remote_exec(data)
 
     else:
         # Decide which code executor to use.
diff --git a/lms/envs/common.py b/lms/envs/common.py
index 40c0343be0..22580a0d59 100644
--- a/lms/envs/common.py
+++ b/lms/envs/common.py
@@ -1630,8 +1630,25 @@ CODE_JAIL = {
 COURSES_WITH_UNSAFE_CODE = []
 
 # Cojail REST service
+ENABLE_CODEJAIL_REST_SERVICE = False
+# .. setting_name: CODE_JAIL_REST_SERVICE_REMOTE_EXEC
+# .. setting_default: 'common.lib.capa.capa.safe_exec.remote_exec.send_safe_exec_request_v0'
+# .. setting_description: Set the python package.module.function that is reponsible of
+#   calling the remote service in charge of jailed code execution
+CODE_JAIL_REST_SERVICE_REMOTE_EXEC = 'common.lib.capa.capa.safe_exec.remote_exec.send_safe_exec_request_v0'
+# .. setting_name: CODE_JAIL_REST_SERVICE_HOST
+# .. setting_default: 'http://127.0.0.1:8550'
+# .. setting_description: Set the codejail remote service host
 CODE_JAIL_REST_SERVICE_HOST = 'http://127.0.0.1:8550'
+# .. setting_name: CODE_JAIL_REST_SERVICE_CONNECT_TIMEOUT
+# .. setting_default: 0.5
+# .. setting_description: Set the number of seconds LMS will wait to establish an internal
+#   connection to the codejail remote service.
 CODE_JAIL_REST_SERVICE_CONNECT_TIMEOUT = 0.5  # time in seconds
+# .. setting_name: CODE_JAIL_REST_SERVICE_READ_TIMEOUT
+# .. setting_default: 3.5
+# .. setting_description: Set the number of seconds LMS will wait for a response from the
+#   codejail remote service endpoint.
 CODE_JAIL_REST_SERVICE_READ_TIMEOUT = 3.5  # time in seconds
 
 

From 2a371e800bfb19c350035193fe454046f133b5dd Mon Sep 17 00:00:00 2001
From: Eric Herrera <eric.herrera@edunext.co>
Date: Sat, 9 Oct 2021 08:25:54 -0500
Subject: [PATCH 5/5] fix: Constrain nltk version for py35 sandbox

nltk 3.6.3 drops support for python 3.5.
---
 requirements/edx-sandbox/py35-constraints.txt | 2 ++
 requirements/edx-sandbox/py35.in              | 2 +-
 requirements/edx-sandbox/py35.txt             | 2 +-
 3 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/requirements/edx-sandbox/py35-constraints.txt b/requirements/edx-sandbox/py35-constraints.txt
index c8cb6ea2b7..23ff7b627b 100644
--- a/requirements/edx-sandbox/py35-constraints.txt
+++ b/requirements/edx-sandbox/py35-constraints.txt
@@ -22,6 +22,8 @@ sympy<1.7.0             # sympy 1.7.0 drops support for Python 3.5
 
 markupsafe<2.0.0        # markupsafe 2.0.0 requires Python >= 3.6
 
+nltk<3.6.3        		# nltk 3.6.3 drops support for Python 3.5
+
 cryptography<3.3        # cryptography 3.3 has dropped python3.5 support.
 PyJWT[crypto]<2.0.0     # PYJWT[crypto]==2.0.1 requires cryptography>=3.3.1
 social-auth-core<4.0.0  # social-auth-core>=4.0.0 requires PYJWT>=2.0.0
diff --git a/requirements/edx-sandbox/py35.in b/requirements/edx-sandbox/py35.in
index d1087cfd84..e4d1a2184b 100644
--- a/requirements/edx-sandbox/py35.in
+++ b/requirements/edx-sandbox/py35.in
@@ -21,7 +21,7 @@ cryptography                        # Implementations of assorted cryptography a
 lxml                                # XML parser
 matplotlib==2.2.4                   # 2D plotting library
 networkx==2.2                       # Utilities for creating, manipulating, and studying network graphs
-nltk                                # Natural language processing; used by the chem package
+nltk==3.6.2                         # Natural language processing; used by the chem package
 numpy==1.16.5                       # Numeric array processing utilities; used by scipy
 openedx-calc<2.0.0
 pyparsing==2.2.0                    # Python Parsing module
diff --git a/requirements/edx-sandbox/py35.txt b/requirements/edx-sandbox/py35.txt
index cc73253ce7..2168f0b7bf 100644
--- a/requirements/edx-sandbox/py35.txt
+++ b/requirements/edx-sandbox/py35.txt
@@ -51,7 +51,7 @@ networkx==2.2
     # via
     #   -c requirements/edx-sandbox/../constraints.txt
     #   -r requirements/edx-sandbox/py35.in
-nltk==3.6.5
+nltk==3.6.2
     # via
     #   -r requirements/edx-sandbox/py35.in
     #   chem