From 4195dc23d13b302c820828c1d600cdfb2d216650 Mon Sep 17 00:00:00 2001 From: Christian Kujau Date: Thu, 5 May 2016 11:16:30 -0700 Subject: check_dig: use +retry instead of +tries After upgrading from an Ubuntu/15.10 to 16.04 installation, I noticed that check_dig is always returning a WARNING: $ /usr/lib/nagios/plugins/check_dig -l localhost -v /usr/bin/dig -p 53 @127.0.0.1 localhost A +tries=3 +time=6 Looking for: 'localhost' DNS WARNING - 0.008 seconds response time (dig returned an error status)|time=0.008274s;;;0.000000 The older Ubuntu installation got its check_dig from the nagios-plugins-standard package[0] which did not include the +tries option. The current Ubuntu version provides its check_dig from the monitoring-plugins-standard package[1], which _does_ use the +tries option that was introduced with df53473[2]. On my system, it so happens that /usr/bin/dig is provided not by the (BIND) dnsutils package but by knot-dnsutils[3] from the Knot DNS project. The Knot dig(1) command doesn't support the +tries option[4] but does support +retry (which is also supported[5] by the BIND dig(1) command). One way to fix that would be for me to install the BIND dnsutils package. But I did not want to do that: it's so much larger in size and pulls in much more dependencies than the knot-dnsutils package. The patch below changes check_dig to use +retry instead of +tries. Both options are similar, but not the same: +retry - Sets the number of times to retry UDP queries to server to T instead of the default, 2. Unlike +tries, this does not include the initial query As number_tries seems to be hard coded to 3, I've lowered DEFAULT_TRIES to 2 so check_dig should behave as before (with +tries=3). Thanks, Christian. [0] http://packages.ubuntu.com/wily/nagios-plugins-standard [1] http://packages.ubuntu.com/xenial/monitoring-plugins-standard [2] https://github.com/monitoring-plugins/monitoring-plugins/commit/df53473 [3] http://packages.ubuntu.com/xenial/knot-dnsutils [4] https://www.knot-dns.cz/docs/2.x/html/man_kdig.html#notes [5] https://ftp.isc.org/isc/bind9/cur/9.10/doc/arm/man.dig.html Signed-off-by: Christian Kujau diff --git a/plugins/check_dig.c b/plugins/check_dig.c index 473d4b9..da4f0de 100644 --- a/plugins/check_dig.c +++ b/plugins/check_dig.c @@ -48,7 +48,7 @@ void print_usage (void); #define UNDEFINED 0 #define DEFAULT_PORT 53 -#define DEFAULT_TRIES 3 +#define DEFAULT_TRIES 2 char *query_address = NULL; char *record_type = "A"; @@ -94,7 +94,7 @@ main (int argc, char **argv) timeout_interval_dig = timeout_interval / number_tries + number_tries; /* get the command to run */ - xasprintf (&command_line, "%s %s %s -p %d @%s %s %s +tries=%d +time=%d", + xasprintf (&command_line, "%s %s %s -p %d @%s %s %s +retry=%d +time=%d", PATH_TO_DIG, dig_args, query_transport, server_port, dns_server, query_address, record_type, number_tries, timeout_interval_dig); alarm (timeout_interval); -- cgit v0.10-9-g596f