Check plugins - check-http

The check-http plugin performs monitoring of a desired server via HTTP connection.

Configurable options

Option	Abbreviation	Required	Explanation	Multiple Allowed	Default Value
--url	-u	✓	URL to connect to
--status	-s		Designate the monitoring results for each HTTP response code in the format key=value	✓
--no-check-certificate			Do not authenticate certificate
--source-ip	-i		Source IP address
	-H		HTTP request header	✓
--pattern	-p		Regular expression to check the HTTP response body
--max-redirects			Maximum number of redirects to follow		10
--method	-m		HTTP request method (Specify GET, HEAD, POST, or PUT)		GET
--connect-to			Connect to HOST2:PORT2 instead of HOST1:PORT1. Specify in the format HOST1:PORT1:HOST2:PORT2	✓
--proxy	-x		Send requests via HTTP proxy. Specify in the format [PROTOCOL://][USER:PASS@]HOST[:PORT]		PORT is 1080
--user			Assign the user ID and password for Basic authentication in the format USER[:PASSWORD]
--require-bytes	-B		Checks that response size matches designated number of bytes		-1
--body	-d		Request body
--min-bytes	-g		Checks that responses are at least the designated number of bytes		-1
--timeout	-t		Timeout length (seconds)		0
--cert-file			Assign certificate used for client authentication
--key-file			Assign key file used for client authentication
--ca-file			Assign CA certificate used for client authentication

Monitoring results by HTTP Response code

The monitoring results for each HTTP response code can be configured via the --status option, but if it they are not configured, the monitoring results are as below.

HTTP Response Code	Monitoring Results
100 level	OK
200 level	OK
300 level	OK
400 level	WARNING
Other	CRITICAL

• The monitoring results for each HTTP response code can be configured via the --status option in the format key-value.
• HTTP response codes may also be assigned to a range, such as 200-404.

Example configurations

To monitor https://mackerel.io/, use the following configuration.

[plugin.checks.https-mackerelio]
command = ["check-http", "-u", "https://mackerel.io"]

To set the monitoring result for the HTTP response of 404 to OK, use the following configuration.

[plugin.checks.https-mackerelio]
command = ["check-http", "-u", "https://mackerel.io", "--status", "404=OK"]

It is also possible to designate the HTTP status code in the format 200-404.

[plugin.checks.https-mackerelio]
command = ["check-http", "-u", "https://mackerel.io", "--status", "200-404=OK"]

Tips

Usually, for monitoring Internet-exposed endpoints as in the [Example configurations](##Example configurations), [External URL Monitoring] (https://mackerel.io/docs/entry/external-monitoring) via the main Mackerel service is recommended.

Please use the check-http plugin as an internal monitoring method for monitoring internal APIs, etc., on the same network which cannot be monitored directly from the Internet.

It can also be used as a substitute to monitor URLs which require client authentication, etc., that are not compatible with external URL monitoring.

Repository

https://github.com/mackerelio/go-check-plugins/tree/master/check-http