collector: Implement uname collector for FreeBSD (#1239)

* collector: Implement uname collector for FreeBSD

Signed-off-by: David O'Rourke <david.orourke@gmail.com>

CHANGELOG.md

@@ -14,6 +14,7 @@ The cpufreq metrics now separate the `cpufreq` and `scaling` data based on what
 * [ENHANCEMENT] Add Infiniband counters #1120
 * [FEATURE] Add a flag to disable exporter metrics #1148
 * [FEATURE] Add kstat-based Solaris metrics for boottime, cpu and zfs collectors #1197
+* [FEATURE] Add uname collector for FreeBSD #1239
 
 ## 0.17.0 / 2018-11-30
 

README.md

@@ -54,7 +54,7 @@ stat | Exposes various statistics from `/proc/stat`. This includes boot time, fo
 textfile | Exposes statistics read from local disk. The `--collector.textfile.directory` flag must be set. | _any_
 time | Exposes the current system time. | _any_
 timex | Exposes selected adjtimex(2) system call stats. | Linux
-uname | Exposes system information as provided by the uname system call. | Linux
+uname | Exposes system information as provided by the uname system call. | FreeBSD, Linux
 vmstat | Exposes statistics from `/proc/vmstat`. | Linux
 xfs | Exposes XFS runtime statistics. | Linux (kernel 4.4+)
 zfs | Exposes [ZFS](http://open-zfs.org/) performance statistics. | [Linux](http://zfsonlinux.org/), Solaris

collector/uname.go

@@ -0,0 +1,72 @@
+// Copyright 2019 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// +build freebsd linux
+// +build !nouname
+
+package collector
+
+import (
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+var unameDesc = prometheus.NewDesc(
+	prometheus.BuildFQName(namespace, "uname", "info"),
+	"Labeled system information as provided by the uname system call.",
+	[]string{
+		"sysname",
+		"release",
+		"version",
+		"machine",
+		"nodename",
+		"domainname",
+	},
+	nil,
+)
+
+type unameCollector struct{}
+type uname struct {
+	SysName    string
+	Release    string
+	Version    string
+	Machine    string
+	NodeName   string
+	DomainName string
+}
+
+func init() {
+	registerCollector("uname", defaultEnabled, newUnameCollector)
+}
+
+// NewUnameCollector returns new unameCollector.
+func newUnameCollector() (Collector, error) {
+	return &unameCollector{}, nil
+}
+
+func (c unameCollector) Update(ch chan<- prometheus.Metric) error {
+	uname, err := getUname()
+	if err != nil {
+		return err
+	}
+
+	ch <- prometheus.MustNewConstMetric(unameDesc, prometheus.GaugeValue, 1,
+		uname.SysName,
+		uname.Release,
+		uname.Version,
+		uname.Machine,
+		uname.NodeName,
+		uname.DomainName,
+	)
+
+	return nil
+}

collector/uname_freebsd.go

@@ -0,0 +1,57 @@
+// Copyright 2019 The Prometheus Authors
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+// +build !nouname
+
+package collector
+
+import (
+	"bytes"
+	"strings"
+
+	"golang.org/x/sys/unix"
+)
+
+func getUname() (uname, error) {
+	var utsname unix.Utsname
+	if err := unix.Uname(&utsname); err != nil {
+		return uname{}, err
+	}
+
+	// We do a little bit of work here to emulate what happens in the Linux
+	// uname calls since FreeBSD uname doesn't have a Domainname.
+	nodename := string(utsname.Nodename[:bytes.IndexByte(utsname.Nodename[:], 0)])
+	split := strings.SplitN(nodename, ".", 2)
+
+	// We'll always have at least a single element in the array. We assume this
+	// is the hostname.
+	hostname := split[0]
+
+	// If we have more than one element, we assume this is the domainname.
+	// Otherwise leave it to "(none)" like Linux.
+	domainname := "(none)"
+	if len(split) > 1 {
+		domainname = split[1]
+	}
+
+	output := uname{
+		SysName:    string(utsname.Sysname[:bytes.IndexByte(utsname.Sysname[:], 0)]),
+		Release:    string(utsname.Release[:bytes.IndexByte(utsname.Release[:], 0)]),
+		Version:    string(utsname.Version[:bytes.IndexByte(utsname.Version[:], 0)]),
+		Machine:    string(utsname.Machine[:bytes.IndexByte(utsname.Machine[:], 0)]),
+		NodeName:   hostname,
+		DomainName: domainname,
+	}
+
+	return output, nil
+}

collector/uname_linux.go

@@ -18,49 +18,23 @@ package collector
 import (
 	"bytes"
 
-	"github.com/prometheus/client_golang/prometheus"
-
 	"golang.org/x/sys/unix"
 )
 
-var unameDesc = prometheus.NewDesc(
-	prometheus.BuildFQName(namespace, "uname", "info"),
-	"Labeled system information as provided by the uname system call.",
-	[]string{
-		"sysname",
-		"release",
-		"version",
-		"machine",
-		"nodename",
-		"domainname",
-	},
-	nil,
-)
-
-type unameCollector struct{}
-
-func init() {
-	registerCollector("uname", defaultEnabled, newUnameCollector)
-}
-
-// NewUnameCollector returns new unameCollector.
-func newUnameCollector() (Collector, error) {
-	return &unameCollector{}, nil
-}
-
-func (c unameCollector) Update(ch chan<- prometheus.Metric) error {
-	var uname unix.Utsname
-	if err := unix.Uname(&uname); err != nil {
-		return err
+func getUname() (uname, error) {
+	var utsname unix.Utsname
+	if err := unix.Uname(&utsname); err != nil {
+		return uname{}, err
 	}
 
-	ch <- prometheus.MustNewConstMetric(unameDesc, prometheus.GaugeValue, 1,
-		string(uname.Sysname[:bytes.IndexByte(uname.Sysname[:], 0)]),
-		string(uname.Release[:bytes.IndexByte(uname.Release[:], 0)]),
-		string(uname.Version[:bytes.IndexByte(uname.Version[:], 0)]),
-		string(uname.Machine[:bytes.IndexByte(uname.Machine[:], 0)]),
-		string(uname.Nodename[:bytes.IndexByte(uname.Nodename[:], 0)]),
-		string(uname.Domainname[:bytes.IndexByte(uname.Domainname[:], 0)]),
-	)
-	return nil
+	output := uname{
+		SysName:    string(utsname.Sysname[:bytes.IndexByte(utsname.Sysname[:], 0)]),
+		Release:    string(utsname.Release[:bytes.IndexByte(utsname.Release[:], 0)]),
+		Version:    string(utsname.Version[:bytes.IndexByte(utsname.Version[:], 0)]),
+		Machine:    string(utsname.Machine[:bytes.IndexByte(utsname.Machine[:], 0)]),
+		NodeName:   string(utsname.Nodename[:bytes.IndexByte(utsname.Nodename[:], 0)]),
+		DomainName: string(utsname.Domainname[:bytes.IndexByte(utsname.Domainname[:], 0)]),
+	}
+
+	return output, nil
 }