From 782eaee100be8baf7f10d06b2a98dcb383047168 Mon Sep 17 00:00:00 2001
From: Dominik Honnef <dominik@honnef.co>
Date: Fri, 30 Dec 2016 07:31:08 +0100
Subject: [PATCH 1/2] Collect CPU temperatures on FreeBSD

---
 collector/cpu_freebsd.go | 26 ++++++++++++++++++++------
 1 file changed, 20 insertions(+), 6 deletions(-)

diff --git a/collector/cpu_freebsd.go b/collector/cpu_freebsd.go
index 11a9b33e..0ec0a1d1 100644
--- a/collector/cpu_freebsd.go
+++ b/collector/cpu_freebsd.go
@@ -16,6 +16,7 @@
 package collector
 
 import (
+	"fmt"
 	"strconv"
 	"unsafe"
 
@@ -78,7 +79,8 @@ func getCPUTimes() ([]cputime, error) {
 }
 
 type statCollector struct {
-	cpu typedDesc
+	cpu  typedDesc
+	temp typedDesc
 }
 
 func init() {
@@ -94,6 +96,11 @@ func NewStatCollector() (Collector, error) {
 			"Seconds the CPU spent in each mode.",
 			[]string{"cpu", "mode"}, nil,
 		), prometheus.CounterValue},
+		temp: typedDesc{prometheus.NewDesc(
+			prometheus.BuildFQName(Namespace, "cpu", "temperature_celsius"),
+			"CPU temperature",
+			[]string{"cpu"}, nil,
+		), prometheus.GaugeValue},
 	}, nil
 }
 
@@ -115,11 +122,18 @@ func (c *statCollector) Update(ch chan<- prometheus.Metric) (err error) {
 		return err
 	}
 	for cpu, t := range cpuTimes {
-		ch <- c.cpu.mustNewConstMetric(float64(t.user), strconv.Itoa(cpu), "user")
-		ch <- c.cpu.mustNewConstMetric(float64(t.nice), strconv.Itoa(cpu), "nice")
-		ch <- c.cpu.mustNewConstMetric(float64(t.sys), strconv.Itoa(cpu), "system")
-		ch <- c.cpu.mustNewConstMetric(float64(t.intr), strconv.Itoa(cpu), "interrupt")
-		ch <- c.cpu.mustNewConstMetric(float64(t.idle), strconv.Itoa(cpu), "idle")
+		lcpu := strconv.Itoa(cpu)
+		ch <- c.cpu.mustNewConstMetric(float64(t.user), lcpu, "user")
+		ch <- c.cpu.mustNewConstMetric(float64(t.nice), lcpu, "nice")
+		ch <- c.cpu.mustNewConstMetric(float64(t.sys), lcpu, "system")
+		ch <- c.cpu.mustNewConstMetric(float64(t.intr), lcpu, "interrupt")
+		ch <- c.cpu.mustNewConstMetric(float64(t.idle), lcpu, "idle")
+
+		temp, err := unix.SysctlUint32(fmt.Sprintf("dev.cpu.%d.temperature", cpu))
+		if err == nil {
+			ftemp := float64(temp-2732) / 10
+			ch <- c.temp.mustNewConstMetric(ftemp, lcpu)
+		}
 	}
 	return err
 }

From d827db8e1728c80ce295bb9a4c25b76c33e77264 Mon Sep 17 00:00:00 2001
From: Dominik Honnef <dominik@honnef.co>
Date: Thu, 5 Jan 2017 06:47:13 +0100
Subject: [PATCH 2/2] Better error handling when collecting CPU temps

Log why we couldn't collect the temperature, and set metric to NaN if
the CPU should support temperature collection but had an error.
---
 collector/cpu_freebsd.go | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/collector/cpu_freebsd.go b/collector/cpu_freebsd.go
index 0ec0a1d1..adbdfcf7 100644
--- a/collector/cpu_freebsd.go
+++ b/collector/cpu_freebsd.go
@@ -17,10 +17,12 @@ package collector
 
 import (
 	"fmt"
+	"math"
 	"strconv"
 	"unsafe"
 
 	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/common/log"
 	"golang.org/x/sys/unix"
 )
 
@@ -130,10 +132,18 @@ func (c *statCollector) Update(ch chan<- prometheus.Metric) (err error) {
 		ch <- c.cpu.mustNewConstMetric(float64(t.idle), lcpu, "idle")
 
 		temp, err := unix.SysctlUint32(fmt.Sprintf("dev.cpu.%d.temperature", cpu))
-		if err == nil {
-			ftemp := float64(temp-2732) / 10
-			ch <- c.temp.mustNewConstMetric(ftemp, lcpu)
+		if err != nil {
+			if err == unix.ENOENT {
+				// No temperature information for this CPU
+				log.Debugf("no temperature information for CPU %d", cpu)
+			} else {
+				// Unexpected error
+				ch <- c.temp.mustNewConstMetric(math.NaN(), lcpu)
+				log.Errorf("failed to query CPU temperature for CPU %d: %s", cpu, err)
+			}
+			continue
 		}
+		ch <- c.temp.mustNewConstMetric(float64(temp-2732)/10, lcpu)
 	}
 	return err
 }