Merge pull request #65 from prometheus/procfs-build-tags

Remove dependency on procfs/cgo in non-procfs systems

prometheus/process_collector.go

@@ -1,6 +1,17 @@
-package prometheus
+// Copyright 2015 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.
 
-import "github.com/prometheus/procfs"
+package prometheus
 
 type processCollector struct {
 	pid             int
@@ -33,7 +44,7 @@ func NewProcessCollectorPIDFn(
 ) *processCollector {
 	c := processCollector{
 		pidFn:     pidFn,
-		collectFn: noopCollect,
+		collectFn: func(chan<- Metric) {},
 
 		cpuTotal: NewCounter(CounterOpts{
 			Namespace: namespace,
@@ -67,9 +78,9 @@ func NewProcessCollectorPIDFn(
 		}),
 	}
 
-	// Use procfs to export metrics if available.
-	if _, err := procfs.NewStat(); err == nil {
-		c.collectFn = c.procfsCollect
+	// Set up process metric collection if supported by the runtime.
+	if processCollectSupported() {
+		c.collectFn = c.processCollect
 	}
 
 	return &c
@@ -89,64 +100,3 @@ func (c *processCollector) Describe(ch chan<- *Desc) {
 func (c *processCollector) Collect(ch chan<- Metric) {
 	c.collectFn(ch)
 }
-
-func noopCollect(ch chan<- Metric) {}
-
-func (c *processCollector) procfsCollect(ch chan<- Metric) {
-	pid, err := c.pidFn()
-	if err != nil {
-		c.reportCollectErrors(ch, err)
-		return
-	}
-
-	p, err := procfs.NewProc(pid)
-	if err != nil {
-		c.reportCollectErrors(ch, err)
-		return
-	}
-
-	if stat, err := p.NewStat(); err != nil {
-		// Report collect errors for metrics depending on stat.
-		ch <- NewInvalidMetric(c.vsize.Desc(), err)
-		ch <- NewInvalidMetric(c.rss.Desc(), err)
-		ch <- NewInvalidMetric(c.startTime.Desc(), err)
-		ch <- NewInvalidMetric(c.cpuTotal.Desc(), err)
-	} else {
-		c.cpuTotal.Set(stat.CPUTime())
-		ch <- c.cpuTotal
-		c.vsize.Set(float64(stat.VirtualMemory()))
-		ch <- c.vsize
-		c.rss.Set(float64(stat.ResidentMemory()))
-		ch <- c.rss
-
-		if startTime, err := stat.StartTime(); err != nil {
-			ch <- NewInvalidMetric(c.startTime.Desc(), err)
-		} else {
-			c.startTime.Set(startTime)
-			ch <- c.startTime
-		}
-	}
-
-	if fds, err := p.FileDescriptorsLen(); err != nil {
-		ch <- NewInvalidMetric(c.openFDs.Desc(), err)
-	} else {
-		c.openFDs.Set(float64(fds))
-		ch <- c.openFDs
-	}
-
-	if limits, err := p.NewLimits(); err != nil {
-		ch <- NewInvalidMetric(c.maxFDs.Desc(), err)
-	} else {
-		c.maxFDs.Set(float64(limits.OpenFiles))
-		ch <- c.maxFDs
-	}
-}
-
-func (c *processCollector) reportCollectErrors(ch chan<- Metric, err error) {
-	ch <- NewInvalidMetric(c.cpuTotal.Desc(), err)
-	ch <- NewInvalidMetric(c.openFDs.Desc(), err)
-	ch <- NewInvalidMetric(c.maxFDs.Desc(), err)
-	ch <- NewInvalidMetric(c.vsize.Desc(), err)
-	ch <- NewInvalidMetric(c.rss.Desc(), err)
-	ch <- NewInvalidMetric(c.startTime.Desc(), err)
-}

prometheus/process_collector_procfs.go

@@ -0,0 +1,84 @@
+// Copyright 2015 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 linux plan9 solaris
+
+package prometheus
+
+import "github.com/prometheus/procfs"
+
+func processCollectSupported() bool {
+	if _, err := procfs.NewStat(); err == nil {
+		return true
+	}
+	return false
+}
+
+func (c *processCollector) processCollect(ch chan<- Metric) {
+	pid, err := c.pidFn()
+	if err != nil {
+		c.reportCollectErrors(ch, err)
+		return
+	}
+
+	p, err := procfs.NewProc(pid)
+	if err != nil {
+		c.reportCollectErrors(ch, err)
+		return
+	}
+
+	if stat, err := p.NewStat(); err != nil {
+		// Report collect errors for metrics depending on stat.
+		ch <- NewInvalidMetric(c.vsize.Desc(), err)
+		ch <- NewInvalidMetric(c.rss.Desc(), err)
+		ch <- NewInvalidMetric(c.startTime.Desc(), err)
+		ch <- NewInvalidMetric(c.cpuTotal.Desc(), err)
+	} else {
+		c.cpuTotal.Set(stat.CPUTime())
+		ch <- c.cpuTotal
+		c.vsize.Set(float64(stat.VirtualMemory()))
+		ch <- c.vsize
+		c.rss.Set(float64(stat.ResidentMemory()))
+		ch <- c.rss
+
+		if startTime, err := stat.StartTime(); err != nil {
+			ch <- NewInvalidMetric(c.startTime.Desc(), err)
+		} else {
+			c.startTime.Set(startTime)
+			ch <- c.startTime
+		}
+	}
+
+	if fds, err := p.FileDescriptorsLen(); err != nil {
+		ch <- NewInvalidMetric(c.openFDs.Desc(), err)
+	} else {
+		c.openFDs.Set(float64(fds))
+		ch <- c.openFDs
+	}
+
+	if limits, err := p.NewLimits(); err != nil {
+		ch <- NewInvalidMetric(c.maxFDs.Desc(), err)
+	} else {
+		c.maxFDs.Set(float64(limits.OpenFiles))
+		ch <- c.maxFDs
+	}
+}
+
+func (c *processCollector) reportCollectErrors(ch chan<- Metric, err error) {
+	ch <- NewInvalidMetric(c.cpuTotal.Desc(), err)
+	ch <- NewInvalidMetric(c.openFDs.Desc(), err)
+	ch <- NewInvalidMetric(c.maxFDs.Desc(), err)
+	ch <- NewInvalidMetric(c.vsize.Desc(), err)
+	ch <- NewInvalidMetric(c.rss.Desc(), err)
+	ch <- NewInvalidMetric(c.startTime.Desc(), err)
+}

prometheus/process_collector_rest.go

@@ -0,0 +1,24 @@
+// Copyright 2015 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 !linux,!plan9,!solaris
+
+package prometheus
+
+func processCollectSupported() bool {
+	return false
+}
+
+func (c *processCollector) processCollect(ch chan<- Metric) {
+	panic("unreachable")
+}