Style changes and cleanup

This patch makes stylistic changes to error strings, unexports method names by lower casing them, removes unused dataSetMetric, and adds copyright/licence information.

Signed-Off-By: Corey Stewart <stewa169@purdue.edu>

README.md

@@ -34,7 +34,7 @@ stat | Exposes various statistics from `/proc/stat`. This includes CPU usage, bo
 textfile | Exposes statistics read from local disk. The `--collector.textfile.directory` flag must be set. | _any_
 time | Exposes the current system time. | _any_
 vmstat | Exposes statistics from `/proc/vmstat`. | Linux
-zfs | Exposes [ZFS](http://open-zfs.org/) performance statistics.<br/> FreeBSD (ARC, zpool), Linux (ARC) | [FreeBSD](https://www.freebsd.org/doc/handbook/zfs.html), [Linux](http://zfsonlinux.org/)
+zfs | Exposes [ZFS](http://open-zfs.org/) performance statistics.<br/> Linux (ARC) | [Linux](http://zfsonlinux.org/)
 
 ### Disabled by default
 

collector/zfs.go

@@ -1,3 +1,16 @@
+// Copyright 2016 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.
+
 package collector
 
 // +build linux freebsd
@@ -33,11 +46,6 @@ type zfsMetric struct {
 	sysctl    zfsSysctl        // The sysctl of the ZFS metric.
 }
 
-type datasetMetric struct {
-	subsystem zfsSubsystemName
-	name      string
-}
-
 // Collector
 
 func init() {
@@ -53,8 +61,12 @@ func NewZFSCollector() (Collector, error) {
 }
 
 func (c *zfsCollector) Update(ch chan<- prometheus.Metric) (err error) {
+	// Arcstats
+	err = c.updateArcstats(ch)
+	if err != nil {
+		return err
+	}
 
-	err = c.zfsAvailable()
 	switch {
 	case err == zfsNotAvailableError:
 		log.Debug(err)
@@ -63,12 +75,6 @@ func (c *zfsCollector) Update(ch chan<- prometheus.Metric) (err error) {
 		return err
 	}
 
-	// Arcstats
-	err = c.updateArcstats(ch)
-	if err != nil {
-		return err
-	}
-
 	// Pool stats
 	return c.updatePoolStats(ch)
 }
@@ -78,8 +84,7 @@ func (s zfsSysctl) metricName() string {
 	return parts[len(parts)-1]
 }
 
-func (c *zfsCollector) ConstSysctlMetric(subsystem zfsSubsystemName, sysctl zfsSysctl, value zfsMetricValue) prometheus.Metric {
-
+func (c *zfsCollector) constSysctlMetric(subsystem zfsSubsystemName, sysctl zfsSysctl, value zfsMetricValue) prometheus.Metric {
 	metricName := sysctl.metricName()
 
 	return prometheus.MustNewConstMetric(
@@ -93,17 +98,3 @@ func (c *zfsCollector) ConstSysctlMetric(subsystem zfsSubsystemName, sysctl zfsS
 		float64(value),
 	)
 }
-
-func (c *zfsCollector) ConstZpoolMetric(pool, name string, value float64) prometheus.Metric {
-	return prometheus.MustNewConstMetric(
-		prometheus.NewDesc(
-			prometheus.BuildFQName(Namespace, string(zpoolSubsystem), name),
-			name,
-			[]string{"pool"},
-			nil,
-		),
-		prometheus.UntypedValue,
-		float64(value),
-		pool,
-	)
-}

collector/zfs_freebsd.go

@@ -58,7 +58,7 @@ func (c *zfsCollector) updateArcstats(ch chan<- prometheus.Metric) (err error) {
 
 	err = c.RunOnStdout(cmd, func(stdout io.Reader) error {
 		return c.parseArcstatsSysctlOutput(stdout, func(sysctl zfsSysctl, value zfsMetricValue) {
-			ch <- c.ConstSysctlMetric(arc, sysctl, zfsMetricValue(value))
+			ch <- c.constSysctlMetric(arc, sysctl, zfsMetricValue(value))
 		})
 	})
 	return err
@@ -102,7 +102,7 @@ func (c *zfsCollector) updatePoolStats(ch chan<- prometheus.Metric) (err error)
 
 	err = c.RunOnStdout(cmd, func(stdout io.Reader) error {
 		return c.parseZpoolOutput(stdout, func(pool, name string, value float64) {
-			ch <- c.ConstZpoolMetric(pool, name, value)
+			ch <- c.constZpoolMetric(pool, name, value)
 		})
 	})
 

collector/zfs_linux.go

@@ -1,3 +1,16 @@
+// Copyright 2016 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.
+
 package collector
 
 import (
@@ -17,14 +30,6 @@ const (
 	zfsArcstatsProcpath = "spl/kstat/zfs/arcstats"
 )
 
-func (c *zfsCollector) zfsAvailable() (err error) {
-	file, err := c.openArcstatsFile()
-	if err != nil {
-		file.Close()
-	}
-	return err
-}
-
 func (c *zfsCollector) openArcstatsFile() (file *os.File, err error) {
 	file, err = os.Open(procFilePath(zfsArcstatsProcpath))
 	if err != nil {
@@ -35,7 +40,6 @@ func (c *zfsCollector) openArcstatsFile() (file *os.File, err error) {
 }
 
 func (c *zfsCollector) updateArcstats(ch chan<- prometheus.Metric) (err error) {
-
 	file, err := c.openArcstatsFile()
 	if err != nil {
 		return err
@@ -43,13 +47,11 @@ func (c *zfsCollector) updateArcstats(ch chan<- prometheus.Metric) (err error) {
 	defer file.Close()
 
 	return c.parseArcstatsProcfsFile(file, func(s zfsSysctl, v zfsMetricValue) {
-		ch <- c.ConstSysctlMetric(arc, s, v)
+		ch <- c.constSysctlMetric(arc, s, v)
 	})
-
 }
 
 func (c *zfsCollector) parseArcstatsProcfsFile(reader io.Reader, handler func(zfsSysctl, zfsMetricValue)) (err error) {
-
 	scanner := bufio.NewScanner(reader)
 
 	parseLine := false

collector/zfs_linux_test.go

@@ -1,3 +1,16 @@
+// Copyright 2016 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.
+
 package collector
 
 import (
@@ -6,7 +19,6 @@ import (
 )
 
 func TestArcstatsParsing(t *testing.T) {
-
 	arcstatsFile, err := os.Open("fixtures/proc/spl/kstat/zfs/arcstats")
 	if err != nil {
 		t.Fatal(err)
@@ -40,5 +52,4 @@ func TestArcstatsParsing(t *testing.T) {
 	if !handlerCalled {
 		t.Fatal("Arcstats parsing handler was not called for some expected sysctls")
 	}
-
 }

collector/zfs_zpool.go

@@ -1,3 +1,16 @@
+// Copyright 2016 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.
+
 package collector
 
 import (
@@ -11,13 +24,12 @@ import (
 // zpool metrics
 
 func (c *zfsCollector) parseZpoolOutput(reader io.Reader, handler func(string, string, float64)) (err error) {
-
 	scanner := bufio.NewScanner(reader)
 	for scanner.Scan() {
 
 		fields := strings.Fields(scanner.Text())
 		if len(fields) != 4 {
-			return fmt.Errorf("Unexpected output of zpool command")
+			return fmt.Errorf("unexpected output of zpool command")
 		}
 
 		valueString := fields[2]
@@ -37,5 +49,4 @@ func (c *zfsCollector) parseZpoolOutput(reader io.Reader, handler func(string, s
 
 	}
 	return scanner.Err()
-
 }

collector/zfs_zpool_test.go

@@ -1,3 +1,16 @@
+// Copyright 2016 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.
+
 package collector
 
 import (
@@ -6,7 +19,6 @@ import (
 )
 
 func TestZpoolParsing(t *testing.T) {
-
 	zpoolOutput, err := os.Open("fixtures/zfs/zpool_stats_stdout.txt")
 	if err != nil {
 		t.Fatal(err)
@@ -55,5 +67,4 @@ func TestZpoolParsing(t *testing.T) {
 	if zrootCapacity != float64(0.5) {
 		t.Fatal("Unexpected value for pool 'zroot's capacity value")
 	}
-
 }