Add collectd-unbound dated 20150830, a collectd plugin to handle

the output from "unbound-control stats".  Based on the code from

  https://github.com/falzm/collectd-unbound

but chenaged from requiring unbound be configured with
  statistics-cumulative: no
to instead requiring
  statistics-cumulative: yes
...and we want all the stats to be collected, and some
of those are counters and some are gauges.

collectd-unbound/DESCR

@@ -0,0 +1,15 @@
+This utility allows you to access Unbound statistics from collectd
+using the exec plugin. It hasn't been thoroughly tested, use it at
+your own risk...
+
+Once the collectd-unbound binary is compiled, copy it wherever you
+want and add the following lines to you collectd configuration:
+
+LoadPlugin exec
+<Plugin "exec">
+    Exec "unbound" "/usr/pkg/bin/collectd-unbound"
+</Plugin>
+
+Note: the utility executes the command unbound-control stats to
+fetch the statistics: make sure the user specified in your exec
+plugin block has the permissions to execute the command.

collectd-unbound/Makefile

@@ -0,0 +1,24 @@
+# $NetBSD$
+#
+
+DISTNAME=		collectd-unbound
+PKGNAME=		${DISTNAME}-20150830
+CATEGORIES=		sysutils
+MASTER_SITES=		${MASTER_SITE_GITHUB:=falzm/}
+GITHUB_PROJECT=		${DISTNAME}
+GITHUB_TAG=		e751f86301
+
+MAINTAINER=		pkgsrc-users@NetBSD.org
+HOMEPAGE=		https://github.com/falzm/collectd-unbound
+COMMENT=		Collectd plugin for submitting unbound statistics
+LICENSE=		modified-bsd
+
+GO_SRCPATH=		github.com/falzm/collectd-unbound
+GO_DIST_BASE=		${DISTNAME}-${GITHUB_TAG}*
+
+DEPENDS+=		go-collectd-[0-9]*:../../sysutils/go-collectd
+DEPENDS+=		collectd-[0-9]*:../../sysutils/collectd
+
+.include "../../sysutils/go-collectd/buildlink3.mk"
+.include "../../lang/go/go-package.mk"
+.include "../../mk/bsd.pkg.mk"

collectd-unbound/PLIST

@@ -0,0 +1,2 @@
+@comment $NetBSD$
+bin/collectd-unbound

collectd-unbound/distinfo

@@ -0,0 +1,6 @@
+$NetBSD$
+
+SHA1 (collectd-unbound-e751f86301.tar.gz) = 5de9eb486314f28f789f79fb69fa464409ea1ce1
+RMD160 (collectd-unbound-e751f86301.tar.gz) = ecb3b6e4e858de57c7913dba3617bf468611ddf1
+Size (collectd-unbound-e751f86301.tar.gz) = 2639 bytes
+SHA1 (patch-collectd-unbound.go) = 8c9b7aee55b78897fe49bdec46a28020ee409071

collectd-unbound/patches/patch-collectd-unbound.go

@@ -0,0 +1,64 @@
+$NetBSD$
+
+Change from requiring unbound be configured with
+
+  statistics-cumulative: no
+
+to instead requiring
+
+  statistics-cumulative: yes
+
+...and we want all the stats to be collected, and some
+of those are counters and some are gauges.
+
+--- collectd-unbound.go.orig	2015-03-21 07:56:41.000000000 +0000
++++ collectd-unbound.go
+@@ -33,7 +33,8 @@ func unboundStats(interval time.Duration
+ 	scanner := bufio.NewScanner(buf)
+ 	for scanner.Scan() {
+ 		line := scanner.Text()
+-		if !strings.HasPrefix(line, "total.") {
++		// Skip per-thread statistics:
++		if strings.HasPrefix(line, "thread") {
+ 			continue
+ 		}
+ 
+@@ -43,7 +44,6 @@ func unboundStats(interval time.Duration
+ 		}
+ 
+ 		metric := fields[0]
+-		metric = strings.TrimPrefix(metric, "total.")
+ 		metric = strings.Replace(metric, ".", "_", -1)
+ 
+ 		value, err := strconv.ParseFloat(fields[1], 64)
+@@ -51,19 +51,28 @@ func unboundStats(interval time.Duration
+ 			log.Printf("error: unable to parse metric value: %v", err)
+ 			continue
+ 		}
++		vartype := "counter"
++		if strings.Contains(fields[1], ".") {
++			vartype = "gauge"
++		}
++		if strings.HasPrefix(metric, "total_requestlist") {
++			vartype = "gauge"
++		}
++		if strings.HasPrefix(metric, "total_recursion") {
++			vartype = "gauge"
++		}
+ 
+ 		vl := api.ValueList{
+ 			Identifier: api.Identifier{
+ 				Host:         exec.Hostname(),
+ 				Plugin:       "unbound",
+-				Type:         "gauge",
++				Type:         vartype,
+ 				TypeInstance: metric,
+ 			},
+ 			Time:     now,
+ 			Interval: interval,
+ 			Values:   []api.Value{api.Gauge(value)},
+ 		}
+-
+ 		exec.Putval.Write(vl)
+ 	}
+ }