This program can be used with Nagios to hit a REST API and compare values to monitor services.
Install this program by downloading the proper version for your operation system on the releases page, then drop the executable in the libexec/ folder of your Nagios installation.
After installing this program you can create custom commands in Nagios to utilize it. Reference the Nagios user manual for more information on custom commands.
| The below usage assumes you are running the program stand-alone on a command line. Usage for a Nagios Command will be nearly identical. | Name/Option | Shorthand | Description |
|---|---|---|---|
--hostname |
-H |
Full address to the REST API endpoint | |
--auth-basic |
-b |
A string in the form <username>:<password> that is used for HTTP Basic Auth |
|
--auth-basic-file |
-bf |
Filepath to a file that contains one line in the format <username>:<password> that is used for HTTP Basic Auth |
|
--key |
-K |
A comma-delimited list of JSON keys to check. More detail on accessing JSON keys are below | |
--critical |
-c |
A comma-delimited list of 'critical' value criteria. Each entry corresponds to a --key entry. See Nagios Plugin documentation on critical values |
|
--warning |
-w |
A comma-delimited list of 'warning' value criteria. Each entry corresponds to a --key entry. See Nagios Plugin documentation on warning values |
|
--timeout |
-t |
Sets a custom timeout, in seconds, to abort the HTTP request should the remote server not respond. Defaults to 10 seconds. |
|
--debug |
-d |
Enable trace mode to see low level data flow in ASCII and HEXADECIMAL representation. | |
--header |
-D |
A string to be added into HTTP request header. | |
--insecure |
-k |
Disables checking peer's SSL certificate (if using SSL/HTTPS). Not recommended to use | |
--http-method |
-m |
Optional; the HTTP method for the API call. Only 'GET', 'POST', and 'PUT' are supported at this time. If omitted 'GET' is assumed. |
Note: Tildes (~) are escaped here as a normal BaSH will expand that to the users home directory. You needn't escape a tilde when writing a custom Nagios Command.
# Check an API endpoint and send a 'critical' value if
# the JSON key `cpu` is above `80`
./check_rest_api -H http://www.contoso.com/api/endpoint -K cpu -c \~:80
# Check an API endpoint and send a 'warning' value if the
# JSON key `files` is less than `23`
./check_rest_api -H http://www.contoso.com/api/endpoint2 -K files 23:
# Check an API endpoint and send a 'warning' if the JSON key `ram` is above `75`
# and a 'critical' if it is above `80`
./check_rest_api -H http://www.contoso.com/api/endpoint3 -K ram -w \~:75 -c \~:80
# Check an API endpoint. Send a 'warning' if `cpu` is above
# 60 or `ram` is above `63`, and a 'critical' if `cpu`
#is above `70` or `ram` is above `83`
./check_rest_api -H http://www.contoso.com/api/endpoint4 -K cpu,ram -w \~:60,\~:63 -c \~:70,\~:83
# Check an API endpoint with HTTP Basic Auth (via CLI)
./check_rest_api -H http://www.contoso.com --auth-basic username:password
# Check an API endpoint with HTTP Basic Auth (with file). The file ./test has one line with the string "username:password" to use for HTTP Basic Auth
./check_rest_api -H http://www.contoso.com --auth-basic-file ./testTo compile the program from scratch:
makecd in the src/ directory and run the command makemake will compile the program called check_rest_apicheck_rest_api has only two external dependencies: