Healthcheck middleware plugins¶
- class oslo_middleware.healthcheck.Healthcheck(*args, **kwargs)¶
Healthcheck application used for monitoring.
It will respond 200 with “OK” as the body. Or a 503 with the reason as the body if one of the backends reports an application issue.
This is useful for the following reasons:
Load balancers can ‘ping’ this url to determine service availability.
Provides an endpoint that is similar to ‘mod_status’ in apache which can provide details (or no details, depending on if configured) about the activity of the server.
(and more)
Example requests/responses (not detailed mode):
$ curl -i -X HEAD "http://0.0.0.0:8775/healthcheck" HTTP/1.1 204 No Content Content-Type: text/plain; charset=UTF-8 Content-Length: 0 Date: Fri, 11 Sep 2015 18:55:08 GMT $ curl -i -X GET "http://0.0.0.0:8775/healthcheck" HTTP/1.1 200 OK Content-Type: text/plain; charset=UTF-8 Content-Length: 2 Date: Fri, 11 Sep 2015 18:55:43 GMT OK $ curl -X GET -i -H "Accept: application/json" "http://0.0.0.0:8775/healthcheck" HTTP/1.0 200 OK Date: Wed, 24 Aug 2016 06:09:58 GMT Content-Type: application/json Content-Length: 63 { "detailed": false, "reasons": [ "OK" ] } $ curl -X GET -i -H "Accept: text/html" "http://0.0.0.0:8775/healthcheck" HTTP/1.0 200 OK Date: Wed, 24 Aug 2016 06:10:42 GMT Content-Type: text/html; charset=UTF-8 Content-Length: 239 <HTML> <HEAD><TITLE>Healthcheck Status</TITLE></HEAD> <BODY> <H2>Result of 1 checks:</H2> <TABLE bgcolor="#ffffff" border="1"> <TBODY> <TR> <TH> Reason </TH> </TR> <TR> <TD>OK</TD> </TR> </TBODY> </TABLE> <HR></HR> </BODY>Example requests/responses (detailed mode):
$ curl -X GET -i -H "Accept: application/json" "http://0.0.0.0:8775/healthcheck" HTTP/1.0 200 OK Date: Wed, 24 Aug 2016 06:11:59 GMT Content-Type: application/json Content-Length: 3480 { "detailed": true, "gc": { "counts": [ 293, 10, 5 ], "threshold": [ 700, 10, 10 ] }, "greenthreads": [ ... ], "now": "2016-08-24 06:11:59.419267", "platform": "Linux-4.2.0-27-generic-x86_64-with-Ubuntu-14.04-trusty", "python_version": "2.7.6 (default, Jun 22 2015, 17:58:13) \n[GCC 4.8.2]", "reasons": [ { "class": "HealthcheckResult", "details": "Path '/tmp/dead' was not found", "reason": "OK" } ], "threads": [ ... ] } $ curl -X GET -i -H "Accept: text/html" "http://0.0.0.0:8775/healthcheck" HTTP/1.0 200 OK Date: Wed, 24 Aug 2016 06:36:07 GMT Content-Type: text/html; charset=UTF-8 Content-Length: 6838 <HTML> <HEAD><TITLE>Healthcheck Status</TITLE></HEAD> <BODY> <H1>Server status</H1> <B>Server hostname:</B><PRE>...</PRE> <B>Current time:</B><PRE>2016-08-24 06:36:07.302559</PRE> <B>Python version:</B><PRE>2.7.6 (default, Jun 22 2015, 17:58:13) [GCC 4.8.2]</PRE> <B>Platform:</B><PRE>Linux-4.2.0-27-generic-x86_64-with-Ubuntu-14.04-trusty</PRE> <HR></HR> <H2>Garbage collector:</H2> <B>Counts:</B><PRE>(77, 1, 6)</PRE> <B>Thresholds:</B><PRE>(700, 10, 10)</PRE> <HR></HR> <H2>Result of 1 checks:</H2> <TABLE bgcolor="#ffffff" border="1"> <TBODY> <TR> <TH> Kind </TH> <TH> Reason </TH> <TH> Details </TH> </TR> <TR> <TD>HealthcheckResult</TD> <TD>OK</TD> <TD>Path '/tmp/dead' was not found</TD> </TR> </TBODY> </TABLE> <HR></HR> <H2>1 greenthread(s) active:</H2> <TABLE bgcolor="#ffffff" border="1"> <TBODY> <TR> <TD><PRE> File "oslo_middleware/healthcheck/__main__.py", line 94, in <module> main() File "oslo_middleware/healthcheck/__main__.py", line 90, in main server.serve_forever() ... </PRE></TD> </TR> </TBODY> </TABLE> <HR></HR> <H2>1 thread(s) active:</H2> <TABLE bgcolor="#ffffff" border="1"> <TBODY> <TR> <TD><PRE> File "oslo_middleware/healthcheck/__main__.py", line 94, in <module> main() File "oslo_middleware/healthcheck/__main__.py", line 90, in main server.serve_forever() .... </TR> </TBODY> </TABLE> </BODY> </HTML>Example of paste configuration:
[app:healthcheck] use = egg:oslo.middleware:healthcheck backends = disable_by_file disable_by_file_path = /var/run/nova/healthcheck_disable [pipeline:public_api] pipeline = healthcheck sizelimit [...] public_service
Multiple filter sections can be defined if it desired to have pipelines with different healthcheck configuration, example:
[composite:public_api] use = egg:Paste#urlmap / = public_api_pipeline /healthcheck = healthcheck_public [composite:admin_api] use = egg:Paste#urlmap / = admin_api_pipeline /healthcheck = healthcheck_admin [pipeline:public_api_pipeline] pipeline = sizelimit [...] public_service [pipeline:admin_api_pipeline] pipeline = sizelimit [...] admin_service [app:healthcheck_public] use = egg:oslo.middleware:healthcheck backends = disable_by_file disable_by_file_path = /var/run/nova/healthcheck_public_disable [filter:healthcheck_admin] use = egg:oslo.middleware:healthcheck backends = disable_by_file disable_by_file_path = /var/run/nova/healthcheck_admin_disable
- classmethod app_factory(global_conf, **local_conf)¶
Factory method for paste.deploy.
- Parameters:
global_conf – dict of options for all middlewares (usually the [DEFAULT] section of the paste deploy configuration file)
local_conf – options dedicated to this middleware (usually the option defined in the middleware section of the paste deploy configuration file)
- classmethod factory(global_conf, **local_conf)¶
Factory method for paste.deploy.
- Parameters:
global_conf – dict of options for all middlewares (usually the [DEFAULT] section of the paste deploy configuration file)
local_conf – options dedicated to this middleware (usually the option defined in the middleware section of the paste deploy configuration file)
- class oslo_middleware.healthcheck.disable_by_file.DisableByFileHealthcheck(*args, **kwargs)¶
DisableByFile healthcheck middleware plugin
This plugin checks presence of a file to report if the service is unavailable or not.
Example of middleware configuration:
[filter:healthcheck] paste.filter_factory = oslo_middleware:Healthcheck.factory path = /healthcheck backends = disable_by_file disable_by_file_path = /var/run/nova/healthcheck_disable # set to True to enable detailed output, False is the default detailed = False
- healthcheck(server_port)¶
method called by the healthcheck middleware
return: HealthcheckResult object
- class oslo_middleware.healthcheck.disable_by_file.DisableByFilesPortsHealthcheck(*args, **kwargs)¶
DisableByFilesPorts healthcheck middleware plugin
This plugin checks presence of a file that is provided for a application running on a certain port to report if the service is unavailable or not.
Example of middleware configuration:
[filter:healthcheck] paste.filter_factory = oslo_middleware:Healthcheck.factory path = /healthcheck backends = disable_by_files_ports disable_by_file_paths = 5000:/var/run/keystone/healthcheck_disable, 35357:/var/run/keystone/admin_healthcheck_disable # set to True to enable detailed output, False is the default detailed = False
- healthcheck(server_port)¶
method called by the healthcheck middleware
return: HealthcheckResult object
Available Plugins¶
disable_by_file¶
DisableByFile healthcheck middleware plugin
This plugin checks presence of a file to report if the service is unavailable or not.
Example of middleware configuration:
[filter:healthcheck]
paste.filter_factory = oslo_middleware:Healthcheck.factory
path = /healthcheck
backends = disable_by_file
disable_by_file_path = /var/run/nova/healthcheck_disable
# set to True to enable detailed output, False is the default
detailed = False
disable_by_files_ports¶
DisableByFilesPorts healthcheck middleware plugin
This plugin checks presence of a file that is provided for a application running on a certain port to report if the service is unavailable or not.
Example of middleware configuration:
[filter:healthcheck]
paste.filter_factory = oslo_middleware:Healthcheck.factory
path = /healthcheck
backends = disable_by_files_ports
disable_by_file_paths = 5000:/var/run/keystone/healthcheck_disable, 35357:/var/run/keystone/admin_healthcheck_disable
# set to True to enable detailed output, False is the default
detailed = False
