Package: django-health-check
django-health-checkThis project checks for various conditions and provides reports when anomalous
behavior is detected.The following health checks are bundled with this project:cachedatabasestoragedisk and memory utilization (viapsutil)AWS S3 storageCelery task queueCelery pingRabbitMQMigrationsWriting your own custom health checks is also very quick and easy.We also like contributions, so don't be afraid to make a pull request.Use CasesThe primary intended use case is to monitor conditions via HTTP(S), with
responses available in HTML and JSON formats. When you get back a response that
includes one or more problems, you can then decide the appropriate course of
action, which could include generating notifications and/or automating the
replacement of a failing node with a new one. If you are monitoring health in a
high-availability environment with a load balancer that returns responses from
multiple nodes, please note that certain checks (e.g., disk and memory usage)
will return responses specific to the node selected by the load balancer.Supported VersionsWe officially only support the latest version of Python as well as the
latest version of Django and the latest Django LTS version.InstallationFirst, install thedjango-health-checkpackage:$pipinstalldjango-health-checkAdd the health checker to a URL you want to use:urlpatterns=[# ...path(r'ht/',include('health_check.urls')),]Add thehealth_checkapplications to yourINSTALLED_APPS:INSTALLED_APPS=[# ...'health_check',# required'health_check.db',# stock Django health checkers'health_check.cache','health_check.storage','health_check.contrib.migrations','health_check.contrib.celery',# requires celery'health_check.contrib.celery_ping',# requires celery'health_check.contrib.psutil',# disk and memory utilization; requires psutil'health_check.contrib.s3boto3_storage',# requires boto3 and S3BotoStorage backend'health_check.contrib.rabbitmq',# requires RabbitMQ broker'health_check.contrib.redis',# requires Redis broker]Note:If usingboto 2.x.xusehealth_check.contrib.s3boto_storage(Optional) If using thepsutilapp, you can configure disk and memory
threshold settings; otherwise below defaults are assumed. If you want to disable
one of these checks, set its value toNone.HEALTH_CHECK={'DISK_USAGE_MAX':90,# percent'MEMORY_MIN':100,# in MB}To use Health Check Subsets, Specify a subset name and associate it with the relevant health check services to utilize Health Check Subsets.HEALTH_CHECK={# ....."SUBSETS":{"startup-probe":["MigrationsHealthCheck","DatabaseBackend"],"liveness-probe":["DatabaseBackend"],"<SUBSET_NAME>":["<Health_Check_Service_Name>"]},# .....}To only execute specific subset of health checkcurl-XGET-H"Accept: application/json"http://www.example.com/ht/startup-probe/If using the DB check, run migrations:$django-adminmigrateTo use the RabbitMQ healthcheck, please make sure that there is a variable namedBROKER_URLon django.conf.settings with the required format to connect to your
rabbit server. For example:BROKER_URL="amqp://myuser:mypassword@localhost:5672/myvhost"To use the Redis healthcheck, please make sure that there is a variable namedREDIS_URLon django.conf.settings with the required format to connect to your redis server. For example:REDIS_URL="redis://localhost:6370"The cache healthcheck tries to write and read a specific key within the cache backend.
It can be customized by settingHEALTHCHECK_CACHE_KEYto another value:HEALTHCHECK_CACHE_KEY="custom_healthcheck_key"Setting up monitoringYou can use tools like Pingdom, StatusCake or other uptime robots to monitor service status.
The/ht/endpoint will respond with an HTTP 200 if all checks passed
and with an HTTP 500 if any of the tests failed.
Getting machine-readable JSON reportsIf you want machine-readable status reports you can request the/ht/endpoint with theAcceptHTTP header set toapplication/jsonor passformat=jsonas a query parameter.The backend will return a JSON response:$curl-v-XGET-H"Accept: application/json"http://www.example.com/ht/>GET/ht/HTTP/1.1>Host:www.example.com>Accept:application/json><HTTP/1.1200OK<Content-Type:application/json{"CacheBackend":"working","DatabaseBackend":"working","S3BotoStorageHealthCheck":"working"}$curl-v-XGEThttp://www.example.com/ht/?format=json>GET/ht/?format=jsonHTTP/1.1>Host:www.example.com><HTTP/1.1200OK<Content-Type:application/json{"CacheBackend":"working","DatabaseBackend":"working","S3BotoStorageHealthCheck":"working"}Writing a custom health checkWriting a health check is quick and easy:fromhealth_check.backendsimportBaseHealthCheckBackendclassMyHealthCheckBackend(BaseHealthCheckBackend):#: The status endpoints will respond with a 200 status code#: even if the check errors.critical_service=Falsedefcheck_status(self):# The test code goes here.# You can use `self.add_error` or# raise a `HealthCheckException`,# similar to Django's form validation.passdefidentifier(self):returnself.__class__.__name__# Display name on the endpoint.After writing a custom checker, register it in your app configuration:fromdjango.appsimportAppConfigfromhealth_check.pluginsimportplugin_dirclassMyAppConfig(AppConfig):name='my_app'defready(self):from.backendsimportMyHealthCheckBackendplugin_dir.register(MyHealthCheckBackend)Make sure the application you write the checker into is registered in yourINSTALLED_APPS.Customizing outputYou can customize HTML or JSON rendering by inheriting fromMainViewinhealth_check.viewsand customizing thetemplate_name,get,render_to_responseandrender_to_response_jsonproperties:# views.pyfromhealth_check.viewsimportMainViewclassHealthCheckCustomView(MainView):template_name='myapp/health_check_dashboard.html'# customize the used templatesdefget(self,request,*args,**kwargs):plugins=[]status=200# needs to be filled status you need# ...if'application/json'inrequest.META.get('HTTP_ACCEPT',''):returnself.render_to_response_json(plugins,status)returnself.render_to_response(plugins,status)defrender_to_response(self,plugins,status):# customize HTML outputreturnHttpResponse('COOL'ifstatus==200else'SWEATY',status=status)defrender_to_response_json(self,plugins,status):# customize JSON outputreturnJsonResponse({str(p.identifier()):'COOL'ifstatus==200else'SWEATY'forpinplugins},status=status)# urls.pyimportviewsurlpatterns=[# ...path(r'ht/',views.HealthCheckCustomView.as_view(),name='health_check_custom'),]Django commandYou can run the Django commandhealth_checkto perform your health checks via the command line,
or periodically with a cron, as follow:django-adminhealth_checkThis should yield the following output:DatabaseHealthCheck      ... working
    CustomHealthCheck        ... unavailable: Something went wrong!Similar to the http version, a critical error will cause the command to quit with the exit code1.Other resourcesdjango-watchmanis a package that does some of the same things in a slightly different way.