The system check framework is a set of static checks for validating Django projects. It detects common problems and provides hints for how to fix them. The framework is extensible so you can easily add your own checks.
For details on how to add your own checks and integrate them with Django’s system checks, see the System check topic guide.
CheckMessageclass CheckMessage(level, msg, hint=None, obj=None, id=None) The warnings and errors raised by system checks must be instances of CheckMessage. An instance encapsulates a single reportable error or warning. It also provides context and hints applicable to the message, and a unique identifier that is used for filtering purposes.
Constructor arguments are:
level DEBUG, INFO, WARNING, ERROR, CRITICAL. If the level is greater or equal to ERROR, then Django will prevent management commands from executing. Messages with level lower than ERROR (i.e. warnings) are reported to the console, but can be silenced.msg hint None can be used.obj __str__() method. The method is used while reporting all messages and its result precedes the message.id applabel.X001, where X is one of the letters CEWID, indicating the message severity (C for criticals, E for errors and so). The number can be allocated by the application, but should be unique within that application.There are subclasses to make creating messages with common levels easier. When using them you can omit the level argument because it is implied by the class name.
class Debug(msg, hint=None, obj=None, id=None) class Info(msg, hint=None, obj=None, id=None) class Warning(msg, hint=None obj=None, id=None) class Error(msg, hint=None, obj=None, id=None) class Critical(msg, hint=None, obj=None, id=None) admin: Checks of any admin site declarations.async_support: Checks asynchronous-related configuration.caches: Checks cache related configuration.compatibility: Flags potential problems with version upgrades.database: Checks database-related configuration issues. Database checks are not run by default because they do more than static code analysis as regular checks do. They are only run by the migrate command or if you specify configured database aliases using the --database option when calling the check command.models: Checks of model, field, and manager definitions.security: Checks security related configuration.signals: Checks on signal declarations and handler registrations.sites: Checks django.contrib.sites configuration.staticfiles: Checks django.contrib.staticfiles configuration.templates: Checks template related configuration.translation: Checks translation related configuration.urls: Checks URL configuration.Some checks may be registered with multiple tags.
The async_support tag was added.
The database checks are now run only for database aliases specified using the check --database option.
The sites tag was added.
The following checks verify your setup for Asynchronous support:
DJANGO_ALLOW_ASYNC_UNSAFE environment variable in deployment. This disables async safety protection.Compatibility checks warn of potential problems that might occur after upgrading Django.
<pattern> has a route that contains (?P<, begins with a ^, or ends with a $. This was likely an oversight when migrating from url() to path().The following checks verify that your CACHES setting is correctly configured:
'default' cache in your CACHES setting.<cache> configuration might expose your cache or lead to corruption of your data because its LOCATION matches/is inside/contains MEDIA_ROOT/STATIC_ROOT/STATICFILES_DIRS.<cache> cache LOCATION is relative. Use an absolute path instead.If you’re using MySQL or MariaDB, the following checks will be performed:
CharFields to have a max_length > 255. This check was changed to mysql.W003 in Django 3.1 as the real maximum size depends on many factors.
<alias>. See also Setting sql_mode.CharFields to have a max_length > 255."__".pk is a reserved word that cannot be used as a field name.choices must be an iterable (e.g., a list or tuple).choices must be an iterable returning (actual value,
human readable name) tuples.db_index must be None, True or False.null=True.validators must be callable.max_length is too small to fit the longest value in choices (<count> characters).<field> default should be a callable instead of an instance so that it’s not shared between all field instances.AutoFields must set primary_key=True.BooleanFields do not accept null values. This check appeared before support for null values was added in Django 2.1.
CharFields must define a max_length attribute.max_length must be a positive integer.max_length is ignored when used with <integer field type>.DecimalFields must define a decimal_places attribute.decimal_places must be a non-negative integer.DecimalFields must define a max_digits attribute.max_digits must be a non-negative integer.max_digits must be greater or equal to decimal_places.FilePathFields must have either allow_files or allow_folders set to True.GenericIPAddressFields cannot accept blank values if null values are not allowed, as blank values are stored as nulls.auto_now, auto_now_add, and default are mutually exclusive. Only one of these options may be present.<database> does not support a database index on <field data type> columns.BinaryField’s default cannot be a string. Use bytes content instead.<database> does not support JSONFields.<database> does not support a database collation on <field_type>s.IPAddressField has been removed except for support in historical migrations.IPAddressField has been deprecated. Support for it (except in historical migrations) will be removed in Django 1.9. This check appeared in Django 1.7 and 1.8.CommaSeparatedIntegerField has been deprecated. Support for it (except in historical migrations) will be removed in Django 2.0. This check appeared in Django 1.10 and 1.11.CommaSeparatedIntegerField is removed except for support in historical migrations.FloatRangeField is deprecated and will be removed in Django 3.1. This check appeared in Django 2.2 and 3.0.NullBooleanField is deprecated. Support for it (except in historical migrations) will be removed in Django 4.0.django.contrib.postgres.fields.JSONField is deprecated. Support for it (except in historical migrations) will be removed in Django 4.0.unique is not a valid argument for a FileField. This check is removed in Django 1.11.primary_key is not a valid argument for a FileField.FileField’s upload_to argument must be a relative path, not an absolute path.ImageField because Pillow is not installed.<swappable> is not of the form app_label.app_name.<SETTING> references <model>, which has not been installed, or is abstract.<app_label>.<model>.id can only be used as a field name if the field also sets primary_key=True.<field name> from parent model <model> clashes with the field <field name> from parent model <model>.<field name> from model <model>.<field name> has column name <column name> that is used by another field.index_together must be a list or tuple.index_together elements must be lists or tuples.unique_together must be a list or tuple.unique_together elements must be lists or tuples.constraints/indexes/index_together/unique_together refers to the nonexistent field <field name>.constraints/indexes/index_together/unique_together refers to a ManyToManyField <field name>, but ManyToManyFields are not supported for that option.ordering must be a tuple or list (even if you want to order by only one field).ordering refers to the nonexistent field, related field, or lookup <field name>.constraints/indexes/index_together/unique_together refers to field <field_name> which is not local to model <model>.<model> contains model fields.<field>. Maximum length is <maximum length> for database <alias>.<M2M field>. Maximum length is <maximum length> for database <alias>.<model>.check() class method is currently overridden.ordering and order_with_respect_to cannot be used together.<function> contains a lazy reference to <app label>.<model>, but app <app label> isn’t installed or doesn’t provide model <model>.<model> cannot start or end with an underscore as it collides with the query lookup syntax.<model> cannot contain double underscores as it collides with the query lookup syntax.<property name> clashes with a related field accessor.primary_key=True.<database> does not support check constraints.db_table <db_table> is used by multiple models: <model list>.<index> is not unique for model <model>.<index> is not unique among models: <model list>.<constraint> is not unique for model <model>.<constraint> is not unique among models: <model list>.<index> cannot start with an underscore or a number.<index> cannot be longer than <max_length> characters.db_table <db_table> is used by multiple models: <model list>.<database> does not support unique constraints with conditions.<database> does not support indexes with conditions.<database> does not support deferrable unique constraints.<database> does not support unique constraints with non-key columns.<database> does not support indexes with non-key columns.constraints refers to the joined field <field name>.django.db.models.AutoField.<database> does not support indexes on expressions.The security checks do not make your site secure. They do not audit code, do intrusion detection, or do anything particularly complex. Rather, they help perform an automated, low-hanging-fruit checklist, that can help you to improve your site’s security.
Some of these checks may not be appropriate for your particular deployment configuration. For instance, if you do your HTTP to HTTPS redirection in a load balancer, it’d be irritating to be constantly warned about not having enabled SECURE_SSL_REDIRECT. Use SILENCED_SYSTEM_CHECKS to silence unneeded checks.
The following checks are run if you use the check --deploy option:
django.middleware.security.SecurityMiddleware in your MIDDLEWARE so the SECURE_HSTS_SECONDS, SECURE_CONTENT_TYPE_NOSNIFF, SECURE_BROWSER_XSS_FILTER, SECURE_REFERRER_POLICY, and SECURE_SSL_REDIRECT settings will have no effect.django.middleware.clickjacking.XFrameOptionsMiddleware in your MIDDLEWARE, so your pages will not be served with an 'x-frame-options' header. Unless there is a good reason for your site to be served in a frame, you should consider enabling this header to help prevent clickjacking attacks.django.middleware.csrf.CsrfViewMiddleware is not in your MIDDLEWARE). Enabling the middleware is the safest approach to ensure you don’t leave any holes.SECURE_HSTS_SECONDS setting. If your entire site is served only over SSL, you may want to consider setting a value and enabling HTTP Strict Transport Security. Be sure to read the documentation first; enabling HSTS carelessly can cause serious, irreversible problems.SECURE_HSTS_INCLUDE_SUBDOMAINS setting to True. Without this, your site is potentially vulnerable to attack via an insecure connection to a subdomain. Only set this to True if you are certain that all subdomains of your domain should be served exclusively via SSL.SECURE_CONTENT_TYPE_NOSNIFF setting is not set to True, so your pages will not be served with an 'X-Content-Type-Options: nosniff' header. You should consider enabling this header to prevent the browser from identifying content types incorrectly.SECURE_BROWSER_XSS_FILTER setting is not set to True, so your pages will not be served with an 'X-XSS-Protection: 1; mode=block' header. You should consider enabling this header to activate the browser’s XSS filtering and help prevent XSS attacks. This check is removed in Django 3.0 as the X-XSS-Protection header is no longer honored by modern browsers.
SECURE_SSL_REDIRECT setting is not set to True. Unless your site should be available over both SSL and non-SSL connections, you may want to either set this setting to True or configure a load balancer or reverse-proxy server to redirect all connections to HTTPS.SECRET_KEY has less than 50 characters, less than 5 unique characters, or it’s prefixed with 'django-insecure-' indicating that it was generated automatically by Django. Please generate a long and random SECRET_KEY, otherwise many of Django’s security-critical features will be vulnerable to attack.django.contrib.sessions in your INSTALLED_APPS but you have not set SESSION_COOKIE_SECURE to True. Using a secure-only session cookie makes it more difficult for network traffic sniffers to hijack user sessions.django.contrib.sessions.middleware.SessionMiddleware in your MIDDLEWARE, but you have not set SESSION_COOKIE_SECURE to True. Using a secure-only session cookie makes it more difficult for network traffic sniffers to hijack user sessions.SESSION_COOKIE_SECURE is not set to True. Using a secure-only session cookie makes it more difficult for network traffic sniffers to hijack user sessions.django.contrib.sessions in your INSTALLED_APPS, but you have not set SESSION_COOKIE_HTTPONLY to True. Using an HttpOnly session cookie makes it more difficult for cross-site scripting attacks to hijack user sessions.django.contrib.sessions.middleware.SessionMiddleware in your MIDDLEWARE, but you have not set SESSION_COOKIE_HTTPONLY to True. Using an HttpOnly session cookie makes it more difficult for cross-site scripting attacks to hijack user sessions.SESSION_COOKIE_HTTPONLY is not set to True. Using an HttpOnly session cookie makes it more difficult for cross-site scripting attacks to hijack user sessions.CSRF_COOKIE_SECURE is not set to True. Using a secure-only CSRF cookie makes it more difficult for network traffic sniffers to steal the CSRF token.CSRF_COOKIE_HTTPONLY is not set to True. Using an HttpOnly CSRF cookie makes it more difficult for cross-site scripting attacks to steal the CSRF token. This check is removed in Django 1.11 as the CSRF_COOKIE_HTTPONLY setting offers no practical benefit.
DEBUG set to True in deployment.django.middleware.clickjacking.XFrameOptionsMiddleware in your MIDDLEWARE, but X_FRAME_OPTIONS is not set to 'DENY'. Unless there is a good reason for your site to serve other parts of itself in a frame, you should change it to 'DENY'.ALLOWED_HOSTS must not be empty in deployment.SECURE_HSTS_PRELOAD setting to True. Without this, your site cannot be submitted to the browser preload list.SECURE_REFERRER_POLICY setting. Without this, your site will not send a Referrer-Policy header. You should consider enabling this header to protect user privacy.SECURE_REFERRER_POLICY setting to an invalid value.The following checks verify that your security-related settings are correctly configured:
DEFAULT_HASHING_ALGORITHM must be 'sha1' or 'sha256'.'path.to.view' does not take the correct number of arguments.'path.to.view' could not be imported.<handler> was connected to the <signal> signal with a lazy reference to the sender <app label>.<model>, but app <app label> isn’t installed or doesn’t provide model <model>.The following checks verify that your TEMPLATES setting is correctly configured:
'APP_DIRS': True in your TEMPLATES but also specify 'loaders' in OPTIONS. Either remove APP_DIRS or remove the 'loaders' option.string_if_invalid in TEMPLATES OPTIONS must be a string but got: {value} ({type}).The following checks are performed on your translation configuration:
LANGUAGE_CODE setting: <value>.LANGUAGES setting: <value>.LANGUAGES_BIDI setting: <value>.LANGUAGE_CODE setting that is not in the LANGUAGES setting.The following checks are performed on your URL configuration:
<pattern> uses include() with a route ending with a $. Remove the dollar from the route to avoid problems including URLs.<pattern> has a route beginning with a /. Remove this slash as it is unnecessary. If this pattern is targeted in an include(), ensure the include() pattern has a trailing /.<pattern> has a name including a :. Remove the colon, to avoid ambiguous namespace references.<pattern> is invalid. Ensure that urlpatterns is a list of path() and/or re_path() instances.<namespace> isn’t unique. You may not be able to reverse all URLs in this namespace.MEDIA_URL/ STATIC_URL setting must end with a slash.handlerXXX view 'path.to.view' does not take the correct number of arguments (…).handlerXXX view 'path.to.view' could not be imported.contrib app checksadminAdmin checks are all performed as part of the admin tag.
The following checks are performed on any ModelAdmin (or subclass) that is registered with the admin site:
raw_id_fields must be a list or tuple.raw_id_fields[n] refers to <field name>, which is not an attribute of <model>.raw_id_fields[n] must be a foreign key or a many-to-many field.fields must be a list or tuple.fieldsets and fields are specified.fields contains duplicate field(s).fieldsets must be a list or tuple.fieldsets[n] must be a list or tuple.fieldsets[n] must be of length 2.fieldsets[n][1] must be a dictionary.fieldsets[n][1] must contain the key fields.fieldsets[n][1].fields[n]/fieldsets[n][m] cannot include the ManyToManyField <field name>, because that field manually specifies a relationship model.exclude must be a list or tuple.exclude contains duplicate field(s).form must inherit from BaseModelForm.filter_vertical must be a list or tuple.filter_horizontal must be a list or tuple.filter_vertical[n]/filter_horizontal[n] refers to <field name>, which is not an attribute of <model>.filter_vertical[n]/filter_horizontal[n] must be a many-to-many field.radio_fields must be a dictionary.radio_fields refers to <field name>, which is not an attribute of <model>.radio_fields refers to <field name>, which is not an instance of ForeignKey, and does not have a choices definition.radio_fields[<field name>] must be either admin.HORIZONTAL or admin.VERTICAL.view_on_site must be either a callable or a boolean value.prepopulated_fields must be a dictionary.prepopulated_fields refers to <field name>, which is not an attribute of <model>.prepopulated_fields refers to <field name>, which must not be a DateTimeField, a ForeignKey, a OneToOneField, or a ManyToManyField field.prepopulated_fields[<field name>] must be a list or tuple.prepopulated_fields refers to <field name>, which is not an attribute of <model>.ordering must be a list or tuple.ordering has the random ordering marker ?, but contains other fields as well.ordering refers to <field name>, which is not an attribute of <model>.readonly_fields must be a list or tuple.readonly_fields[n] is not a callable, an attribute of <ModelAdmin class>, or an attribute of <model>.autocomplete_fields must be a list or tuple.autocomplete_fields[n] refers to <field name>, which is not an attribute of <model>.autocomplete_fields[n] must be a foreign key or a many-to-many field.<model> has to be registered to be referenced by <modeladmin>.autocomplete_fields.<modeladmin> must define search_fields, because it’s referenced by <other_modeladmin>.autocomplete_fields.ModelAdminThe following checks are performed on any ModelAdmin that is registered with the admin site:
save_as must be a boolean.save_on_top must be a boolean.inlines must be a list or tuple.<InlineModelAdmin class> must inherit from InlineModelAdmin.<InlineModelAdmin class> must have a model attribute.<InlineModelAdmin class>.model must be a Model.list_display must be a list or tuple.list_display[n] refers to <label>, which is not a callable, an attribute of <ModelAdmin class>, or an attribute or method on <model>.list_display[n] must not be a ManyToManyField field.list_display_links must be a list, a tuple, or None.list_display_links[n] refers to <label>, which is not defined in list_display.list_filter must be a list or tuple.list_filter[n] must inherit from ListFilter.list_filter[n] must not inherit from FieldListFilter.list_filter[n][1] must inherit from FieldListFilter.list_filter[n] refers to <label>, which does not refer to a Field.list_select_related must be a boolean, tuple or list.list_per_page must be an integer.list_max_show_all must be an integer.list_editable must be a list or tuple.list_editable[n] refers to <label>, which is not an attribute of <model>.list_editable[n] refers to <label>, which is not contained in list_display.list_editable[n] cannot be in both list_editable and list_display_links.list_editable[n] refers to the first field in list_display (<label>), which cannot be used unless list_display_links is set.list_editable[n] refers to <field name>, which is not editable through the admin.search_fields must be a list or tuple.date_hierarchy refers to <field name>, which does not refer to a Field.date_hierarchy must be a DateField or DateTimeField.<modeladmin> must define a has_<foo>_permission() method for the <action> action.__name__ attributes of actions defined in <modeladmin> must be unique. Name <name> is not unique.InlineModelAdminThe following checks are performed on any InlineModelAdmin that is registered as an inline on a ModelAdmin.
<field name>, because it is the foreign key to the parent model <app_label>.<model>.<model> has no ForeignKey to <parent model>./ <model> has more than one ForeignKey to <parent model>. You must specify a fk_name attribute.extra must be an integer.max_num must be an integer.min_num must be an integer.formset must inherit from BaseModelFormSet.GenericInlineModelAdminThe following checks are performed on any GenericInlineModelAdmin that is registered as an inline on a ModelAdmin.
'ct_field' references <label>, which is not a field on <model>.'ct_fk_field' references <label>, which is not a field on <model>.<model> has no GenericForeignKey.<model> has no GenericForeignKey using content type field <field name> and object ID field <field name>.AdminSiteThe following checks are performed on the default AdminSite:
django.contrib.contenttypes must be in INSTALLED_APPS in order to use the admin application.django.contrib.auth.context_processors.auth must be enabled in DjangoTemplates (TEMPLATES) if using the default auth backend in order to use the admin application.django.template.backends.django.DjangoTemplates instance must be configured in TEMPLATES in order to use the admin application.django.contrib.messages.context_processors.messages must be enabled in DjangoTemplates (TEMPLATES) in order to use the admin application.django.contrib.auth must be in INSTALLED_APPS in order to use the admin application.django.contrib.messages must be in INSTALLED_APPS in order to use the admin application.django.contrib.auth.middleware.AuthenticationMiddleware must be in MIDDLEWARE in order to use the admin application.django.contrib.messages.middleware.MessageMiddleware must be in MIDDLEWARE in order to use the admin application.django.contrib.sessions.middleware.SessionMiddleware must be in MIDDLEWARE in order to use the admin application.django.template.context_processors.request must be enabled in DjangoTemplates (TEMPLATES) in order to use the admin navigation sidebar.authREQUIRED_FIELDS must be a list or tuple.USERNAME_FIELD for a custom user model must not be included in REQUIRED_FIELDS.<field> must be unique because it is named as the USERNAME_FIELD.<field> is named as the USERNAME_FIELD, but it is not unique.<codename> clashes with a builtin permission for model <model>.<codename> is duplicated for model <model>.verbose_name of model <model> must be at most 244 characters for its builtin permission names to be at most 255 characters.<name> of model <model> is longer than 255 characters.<User model>.is_anonymous must be an attribute or property rather than a method. Ignoring this is a security issue as anonymous users will be treated as authenticated!<User model>.is_authenticated must be an attribute or property rather than a method. Ignoring this is a security issue as anonymous users will be treated as authenticated!<model> must be at most 93 characters for its builtin permission names to be at most 100 characters.<codename> of model <model> is longer than 100 characters.contenttypesThe following checks are performed when a model contains a GenericForeignKey or GenericRelation:
GenericForeignKey object ID references the nonexistent field <field>.GenericForeignKey content type references the nonexistent field <field>.<field> is not a ForeignKey.<field> is not a ForeignKey to contenttypes.ContentType.postgresThe following checks are performed on django.contrib.postgres model fields:
<field> default should be a callable instead of an instance so that it’s not shared between all field instances. This check was changed to fields.E010 in Django 3.1.sitesThe following checks are performed on any model using a CurrentSiteManager:
CurrentSiteManager could not find a field named <field name>.CurrentSiteManager cannot use <field> as it is not a foreign key or a many-to-many field.The following checks verify that django.contrib.sites is correctly configured:
SITE_ID setting must be an integer.staticfilesThe following checks verify that django.contrib.staticfiles is correctly configured:
STATICFILES_DIRS setting is not a tuple or list.STATICFILES_DIRS setting should not contain the STATIC_ROOT setting.<prefix> in the STATICFILES_DIRS setting must not end with a slash.
© Django Software Foundation and individual contributors
Licensed under the BSD License.
https://docs.djangoproject.com/en/3.2/ref/checks/