Golang Icinga/Nagios HTTPS Checker

Icinga/Nagios plugin, checks that a site returns a 2xx-series status code, returns content, and has a valid certificate.

User configurable warning and critical levels for the number of days left in the certificate validity period.

Installation and requirements

The pre-compiled binaries available on the releases page are self-contained and have no dependancies to run.

If you wish to compile it yourself, you'll need to install go and make. It's been tested on:

• Golang 1.20.3
• GNU Make 4.2.1

It'll probably build just fine on many other versions. To build, simply run make:

make           # Make all builds
make linux     # Make linux binary
make windows   # Make windows binary
make macos     # Make macOS binary

You can run make help for additional options.

Usage

usage:
  required
    -h string
        Fully-qualified domain name to check.
  optional
    -c int
            Number of days for which the TLS certificate must be valid before a critical state is returned. (default 5)
    -r int
            Number of redirects to follow. (default 20)
    -s string
            Custom string to check for in the response body. (default "")
    -t int
            Timeout length in seconds, requests that do not finish before timeout are considered failed. (default 30)
    -u string
            Custom user-agent string. (default "check_https_go")
    -v    More verbose output includes details of any redirects.
    -w int
            Number of days for which the TLS certificate must be valid before a warning state is returned. (default 10)

Version history

1.3—Add custom string to check the content returned by the page. 1.2—Follow Redirect feature now handles 307s. 1.1—Added configurable timeout. Default remains at 30, but you can now increase or decrease this.

License

Golang Icinga/Nagios HTTPS Checker is licensed under the terms of the GNU General Public License Version 3.