From 63434454339988e23dbdd3557c8ae07cf6e31180 Mon Sep 17 00:00:00 2001
From: Oliver <oliver.henry.walters@gmail.com>
Date: Fri, 15 Oct 2021 15:05:55 +1100
Subject: [PATCH 1/2] Add support for backend-specific database functionality

---
 InvenTree/InvenTree/settings.py | 100 +++++++++++++++++++++-----------
 1 file changed, 66 insertions(+), 34 deletions(-)

diff --git a/InvenTree/InvenTree/settings.py b/InvenTree/InvenTree/settings.py
index a07324ec84..9b38c27159 100644
--- a/InvenTree/InvenTree/settings.py
+++ b/InvenTree/InvenTree/settings.py
@@ -385,39 +385,6 @@ Q_CLUSTER = {
     'sync': False,
 }
 
-# Markdownx configuration
-# Ref: https://neutronx.github.io/django-markdownx/customization/
-MARKDOWNX_MEDIA_PATH = datetime.now().strftime('markdownx/%Y/%m/%d')
-
-# Markdownify configuration
-# Ref: https://django-markdownify.readthedocs.io/en/latest/settings.html
-
-MARKDOWNIFY_WHITELIST_TAGS = [
-    'a',
-    'abbr',
-    'b',
-    'blockquote',
-    'em',
-    'h1', 'h2', 'h3',
-    'i',
-    'img',
-    'li',
-    'ol',
-    'p',
-    'strong',
-    'ul'
-]
-
-MARKDOWNIFY_WHITELIST_ATTRS = [
-    'href',
-    'src',
-    'alt',
-]
-
-MARKDOWNIFY_BLEACH = False
-
-DATABASES = {}
-
 """
 Configure the database backend based on the user-specified values.
 
@@ -484,7 +451,41 @@ logger.info(f"DB_ENGINE: {db_engine}")
 logger.info(f"DB_NAME: {db_name}")
 logger.info(f"DB_HOST: {db_host}")
 
-DATABASES['default'] = db_config
+"""
+In addition to base-level database configuration, we may wish to specify specific options to the database backend
+Ref: https://docs.djangoproject.com/en/3.2/ref/settings/#std:setting-OPTIONS
+
+Various database options can be specified in config.yaml if required:
+
+""" 
+
+db_options = db_config.get('OPTIONS', db_config.get('options', {}))
+
+# Specific options for postgres backend
+if 'postgres' in db_engine:
+    from psycopg2.extensions import ISOLATION_LEVEL_READ_COMMITTED, ISOLATION_LEVEL_SERIALIZABLE
+
+    # Connection timeout
+    if 'connect_timeout' not in db_options:
+        db_options['connect_timeout'] = int(os.getenv('INVENTREE_DB_TIMEOUT'), 2)
+
+# Specific options for MySql / MariaDB backend
+if 'mysql' in db_engine:
+    # TODO
+    pass
+
+# Specific options for sqlite backend
+if 'sqlite' in db_engine:
+    # TODO
+    pass
+
+# Provide OPTIONS dict back to the database configuration dict
+db_config['OPTIONS'] = db_options
+
+DATABASES = {
+    'default': db_config
+}
+
 
 CACHES = {
     'default': {
@@ -683,3 +684,34 @@ ACCOUNT_FORMS = {
 
 SOCIALACCOUNT_ADAPTER = 'InvenTree.forms.CustomSocialAccountAdapter'
 ACCOUNT_ADAPTER = 'InvenTree.forms.CustomAccountAdapter'
+
+# Markdownx configuration
+# Ref: https://neutronx.github.io/django-markdownx/customization/
+MARKDOWNX_MEDIA_PATH = datetime.now().strftime('markdownx/%Y/%m/%d')
+
+# Markdownify configuration
+# Ref: https://django-markdownify.readthedocs.io/en/latest/settings.html
+
+MARKDOWNIFY_WHITELIST_TAGS = [
+    'a',
+    'abbr',
+    'b',
+    'blockquote',
+    'em',
+    'h1', 'h2', 'h3',
+    'i',
+    'img',
+    'li',
+    'ol',
+    'p',
+    'strong',
+    'ul'
+]
+
+MARKDOWNIFY_WHITELIST_ATTRS = [
+    'href',
+    'src',
+    'alt',
+]
+
+MARKDOWNIFY_BLEACH = False

From 603f7d5f45ce694f5fa2849643a2138a1c5068f6 Mon Sep 17 00:00:00 2001
From: Oliver <oliver.henry.walters@gmail.com>
Date: Fri, 15 Oct 2021 15:13:06 +1100
Subject: [PATCH 2/2] Fixes

---
 InvenTree/InvenTree/settings.py | 16 +++++++++++-----
 1 file changed, 11 insertions(+), 5 deletions(-)

diff --git a/InvenTree/InvenTree/settings.py b/InvenTree/InvenTree/settings.py
index 9b38c27159..2095cab533 100644
--- a/InvenTree/InvenTree/settings.py
+++ b/InvenTree/InvenTree/settings.py
@@ -454,11 +454,9 @@ logger.info(f"DB_HOST: {db_host}")
 """
 In addition to base-level database configuration, we may wish to specify specific options to the database backend
 Ref: https://docs.djangoproject.com/en/3.2/ref/settings/#std:setting-OPTIONS
+"""
 
-Various database options can be specified in config.yaml if required:
-
-""" 
-
+# 'OPTIONS' or 'options' can be specified in config.yaml
 db_options = db_config.get('OPTIONS', db_config.get('options', {}))
 
 # Specific options for postgres backend
@@ -467,7 +465,15 @@ if 'postgres' in db_engine:
 
     # Connection timeout
     if 'connect_timeout' not in db_options:
-        db_options['connect_timeout'] = int(os.getenv('INVENTREE_DB_TIMEOUT'), 2)
+        db_options['connect_timeout'] = int(os.getenv('INVENTREE_DB_TIMEOUT', 2))
+
+    # Postgres's default isolation level is Read Committed which is
+    # normally fine, but most developers think the database server is
+    # actually going to do Serializable type checks on the queries to
+    # protect against simultaneous changes.
+    if 'isolation_level' not in db_options:
+        serializable = _is_true(os.getenv("PG_ISOLATION_SERIALIZABLE", "true"))
+        db_options['isolation_level'] = ISOLATION_LEVEL_SERIALIZABLE if serializable else ISOLATION_LEVEL_READ_COMMITTED
 
 # Specific options for MySql / MariaDB backend
 if 'mysql' in db_engine: