nagiosplugin: how to show different fmt_metric based on the value?

问题

I'm writing a Nagios plugin that use xml output from sslyze to calculate SSL score based on Qualys Server Rating Guide.

Here're my code:

            if certificateMatchesServerHostname == 'True' and expire_in.days > 0 and validationResult == 'ok':
                ...
                final_score = protocol_score * 0.3 + key_score * 0.3 + cipher_score * 0.4
                return [nap.Metric('sslscore', final_score, min=0, max=100)]
            elif certificateMatchesServerHostname != 'True':
                return [nap.Metric('serverHostname', hostnameValidation[0].attrib['serverHostname'])]
            elif expire_in.days <= 0:
                return [nap.Metric('expireInDays', expire_in.days)]
            elif validationResult != 'ok':
                return [nap.Metric('validationResult', validationResult)]


@nap.guarded
def main():
    check = nap.Check(
        SslConfiguration(),
        nap.ScalarContext('sslscore', nap.Range('@65:80'), nap.Range('@0:65')),
        nap.ScalarContext('serverHostname', fmt_metric='The certificate does not match the host name {value}'),
        nap.ScalarContext('expireInDays', nap.Range('@:0'), fmt_metric='The certificate expired {value} days ago'),
        nap.ScalarContext('validationResult', fmt_metric='This server\'s certificate is not trusted: {value}'))
    check.main(timeout=60)

The reason I have to use multiple ScalarContext is I would like to show different fmt_metric if there is a problem with SSL certificate: does not match, expired, not trust, ...

With the above code, the output looks something like this:

SSLCONFIGURATION CRITICAL - The certificate does not match the host name a.b.c.d (outside range 0:)
critical: The certificate does not match the host name a.b.c.d (outside range 0:)
| serverHostname=a.b.c.d

What I really want to display is:

SSLCONFIGURATION CRITICAL - final_score is 0 (The certificate does not match the host name a.b.c.d) | sslscore=0;@65:80;@65;0;100

So, I have some questions:

How can I display different fmt_metric based on the sslscore value, in only one context sslscore?

How to remove the redundant line (2nd)?

critical: The certificate does not match the host name a.b.c.d (outside range 0:)

How to move the metric (3rd line) to at the end of the first line?

回答1:

With a help from my friend, I finally solved the problem.

About the first question, we can use the nagiosplugin.summary module to change the status line, something like this:

class SslConfiguration(nap.Resource):
    def __init__(self, host, port):
        self.host = host
        self.port = port

    def check(self):
            ...
        if hostname_validation.startswith('OK') and expire_in.days > 0 and is_trusted == 'OK':
            final_score = protocol_score * 0.3 + key_score * 0.3 + cipher_score * 0.4
        else:
            final_score = 0
        return (hostname_validation, is_trusted, expire_in.days, final_score)

    def probe(self):
        if self.check()[3] > 0:
            return [nap.Metric('sslscore', self.check()[3])]
        elif not self.check()[0].startswith('OK'):
            return [nap.Metric('sslscore', 0, context='serverHostname')]
        elif self.check()[1] != 'OK':
            return [nap.Metric('sslscore', 0, context='validationResult')]
        elif self.check()[2] <= 0:
            return [nap.Metric('sslscore', 0, context='expireInDays')]


class SslSummary(nap.Summary):
    def __init__(self, host, port):
        self.host = host
        self.port = port

    def status_line(self, results):
        ssl_configuration = SslConfiguration(self.host, self.port)
        if results['sslscore'].context.name == 'serverHostname':
            return "sslscore is 0 ({0})".format(ssl_configuration.check()[0])
        elif results['sslscore'].context.name == 'validationResult':
            return "sslscore is 0 ({0})".format(ssl_configuration.check()[1])
        elif results['sslscore'].context.name == 'expireInDays':
            return "sslscore is 0 (The certificate expired {0} days ago)".format(ssl_configuration.check()[2])

    def problem(self, results):
        return self.status_line(results)

The second and third question can be solved by setting the verbose parameter of main() to zero:

@nap.guarded
def main():
    parser = argparse.ArgumentParser()
    parser.add_argument('-H', '--host', type=str, required=True)
    parser.add_argument('-p', '--port', type=int, default=443)
    parser.add_argument('-v', '--verbose', action='count', default=0, help="increase output verbosity (use up to 3 times)")
    parser.add_argument('-t', '--timeout', type=int, default=60)
    args = parser.parse_args()

    check = nap.Check(
        SslConfiguration(args.host, args.port),
        nap.ScalarContext('sslscore', nap.Range('@65:80'), nap.Range('@0:65')),
        nap.ScalarContext('serverHostname', nap.Range('@65:80'), nap.Range('@0:65')),
        nap.ScalarContext('validationResult', nap.Range('@65:80'), nap.Range('@0:65')),
        nap.ScalarContext('expireInDays', nap.Range('@65:80'), nap.Range('@0:65')),
        SslSummary(args.host, args.port))
    check.main(args.verbose, args.timeout)

Now the output can help sysadmin to know what is going on:

check_ssl_configuration.py -H google.com
SSLCONFIGURATION OK - sslscore is 87 | sslscore=87.0;@65:80;@65

check_ssl_configuration.py -H 173.194.127.169
SSLCONFIGURATION CRITICAL - sslscore is 0 (FAILED - Certificate does NOT match 173.194.127.169) | sslscore=0;@65:80;@65

来源：https://stackoverflow.com/questions/23976631/nagiosplugin-how-to-show-different-fmt-metric-based-on-the-value

标签

python

plugins

nagios