Golang Icinga/Nagios HTTPS Checker

Icinga/Nagios plugin, checks that a site returns an expected status code, returns expected 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
    -a string
        Comma-seperated list of status codes. (default "200,201,202,203,204,205,206,207,208,226")
    -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

• 1.4—Add parameter for configuring status code check.
• 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.