Implement proper unregistering

Author: MMulthaupt

README.md

@@ -17,11 +17,45 @@ Makes available the following metrics for Prometheus for processes matching a gi
 ### Usage
 
 ```sh
-./process_exporter -namespace # Prometheus metric namespace
+./process_exporter -namespace # Prometheus metric namespace (default: "my")
                    -binary # Name of binary to monitor
-                   -nameflag # Infer value of "name"-label from value of this command line flag of monitored process
+                   -nameflag # Infer value of "name"-label from value of this command line flag of monitored process (default: "name")
                    -port # Port to listen on for request (default: 80)
-                   -interval # Interval between metrics being refreshed (default: 10 seconds)
+                   -interval # Interval between metrics being refreshed, in seconds (default: 10)
+```
+
+### Metrics
+
+Example output from `curl localhost/metrics` for `process_exporter -binary top -nameflag d` for `top -d 1`. (Exploiting top's `-d` parameter as a unique identifier)
+
+```sh
+# HELP my_cpu Process CPU usage (%)
+# TYPE my_cpu gauge
+my_cpu{bin="top",name="1",pid="26436"} 3.0630784711756576
+
+# HELP my_ram Process RAM usage (bytes)
+# TYPE my_ram gauge
+my_ram{bin="top",name="1",pid="26436"} 3.80928e+06
+
+# HELP my_storage_read_bytes Total read from storage (bytes)
+# TYPE my_storage_read_bytes gauge
+my_storage_read_bytes{bin="top",name="1",pid="26436"} 0
+
+# HELP my_storage_reads Total reads from storage
+# TYPE my_storage_reads gauge
+my_storage_reads{bin="top",name="1",pid="26436"} 27973
+
+# HELP my_storage_write_bytes Total written to storage (bytes)
+# TYPE my_storage_write_bytes gauge
+my_storage_write_bytes{bin="top",name="1",pid="26436"} 0
+
+# HELP my_storage_writes Total writes to storage
+# TYPE my_storage_writes gauge
+my_storage_writes{bin="top",name="1",pid="26436"} 91
+
+# HELP my_swap Process swap usage (bytes)
+# TYPE my_swap gauge
+my_swap{bin="top",name="1",pid="26436"} 0
 ```
 
 ### TODO

cmd/exporter/flags/flags.go

@@ -4,7 +4,7 @@ import "flag"
 
 func Parse(arguments []string) (namespace, binary, argName string, port int, interval float64) {
 	flagSet := flag.NewFlagSet("flags", flag.ExitOnError)
-	namespacePtr := flagSet.String("namespace", "mine", "Prometheus metric namespace.")
+	namespacePtr := flagSet.String("namespace", "my", "Prometheus metric namespace.")
 	binaryPtr := flagSet.String("binary", "", "Filter which processes to watch by binary name. This is limited to 15 bytes because of the kernel.")
 	nameFlagPtr := flagSet.String("nameflag", "name", "Set Prometheus \"name\"-label value to value of this command line argument of the monitored processes.")
 	portPtr := flagSet.Int("port", 80, "Port on which to listen to requests to /metrics.")

cmd/exporter/metrics/proc_metrics.go

@@ -8,14 +8,14 @@ import (
 )
 
 type ProcessMetrics struct {
-	cpuDuration    float64
-	cpuSampleTime  time.Time
-	ram            uint64
-	swap           uint64
-	diskReadBytes  uint64
-	diskWriteBytes uint64
-	diskReadCount  uint64
-	diskWriteCount uint64
+	cpuDuration       float64
+	cpuSampleTime     time.Time
+	ram               uint64
+	swap              uint64
+	storageReadBytes  uint64
+	storageWriteBytes uint64
+	storageReadCount  uint64
+	storageWriteCount uint64
 }
 
 func getProcMetrics(pid int) (processMetrics *ProcessMetrics, err error) {
@@ -39,9 +39,9 @@ func getProcMetrics(pid int) (processMetrics *ProcessMetrics, err error) {
 	if err != nil {
 		return nil, fmt.Errorf("could not read disk IO info of PID %d: %w", pid, err)
 	}
-	m.diskReadBytes = ioDisk.ReadBytes
-	m.diskWriteBytes = ioDisk.WriteBytes
-	m.diskReadCount = ioDisk.ReadCount
-	m.diskWriteCount = ioDisk.WriteCount
+	m.storageReadBytes = ioDisk.ReadBytes
+	m.storageWriteBytes = ioDisk.WriteBytes
+	m.storageReadCount = ioDisk.ReadCount
+	m.storageWriteCount = ioDisk.WriteCount
 	return m, nil
 }

cmd/exporter/metrics/prom_proc_metrics.go

@@ -10,22 +10,23 @@ import (
 )
 
 type PrometheusProcessMetrics struct {
-	previousMetrics     *ProcessMetrics
-	cpuGauge            prometheus.Gauge
-	ramGauge            prometheus.Gauge
-	swapGauge           prometheus.Gauge
-	diskReadBytesGauge  prometheus.Gauge
-	diskWriteBytesGauge prometheus.Gauge
-	diskReadCountGauge  prometheus.Gauge
-	diskWriteCountGauge prometheus.Gauge
+	registeredCollectors      []prometheus.Collector
+	previousMetrics           *ProcessMetrics
+	cpuGauge                  prometheus.Gauge
+	ramGauge                  prometheus.Gauge
+	swapGauge                 prometheus.Gauge
+	storageReadBytesGauge     prometheus.Gauge
+	storageWriteBytesGauge    prometheus.Gauge
+	storagediskReadCountGauge prometheus.Gauge
+	storageWriteCountGauge    prometheus.Gauge
 }
 
 func newPrometheusProcessMetrics(proc ps.Process, descriptiveName, metricNamespace string) (processMetrics *PrometheusProcessMetrics) {
 	processMetrics = &PrometheusProcessMetrics{}
 	binaryName := filepath.Base(proc.Executable())
 	pid := fmt.Sprintf("%d", proc.Pid())
 	processMetrics.makeGauges(metricNamespace, pid, binaryName, descriptiveName)
-	processMetrics.makeDiskGauges(metricNamespace, pid, binaryName, descriptiveName)
+	processMetrics.makeStorageGauges(metricNamespace, pid, binaryName, descriptiveName)
 	return processMetrics
 }
 
@@ -50,81 +51,78 @@ func (pm *PrometheusProcessMetrics) makeGauges(metricNamespace, pid, binaryName,
 	})
 }
 
-func (pm *PrometheusProcessMetrics) makeDiskGauges(metricNamespace, pid, binaryName, descriptiveName string) {
-	pm.diskReadBytesGauge = prometheus.NewGauge(prometheus.GaugeOpts{
+func (pm *PrometheusProcessMetrics) makeStorageGauges(metricNamespace, pid, binaryName, descriptiveName string) {
+	pm.storageReadBytesGauge = prometheus.NewGauge(prometheus.GaugeOpts{
 		Namespace:   metricNamespace,
-		Name:        "disk_read_bytes",
-		Help:        "Total read from disk (bytes)",
+		Name:        "storage_read_bytes",
+		Help:        "Total read from storage (bytes)",
 		ConstLabels: prometheus.Labels{"pid": pid, "bin": binaryName, "name": descriptiveName},
 	})
-	pm.diskWriteBytesGauge = prometheus.NewGauge(prometheus.GaugeOpts{
+	pm.storageWriteBytesGauge = prometheus.NewGauge(prometheus.GaugeOpts{
 		Namespace:   metricNamespace,
-		Name:        "disk_write_bytes",
-		Help:        "Total written to disk (bytes)",
+		Name:        "storage_write_bytes",
+		Help:        "Total written to storage (bytes)",
 		ConstLabels: prometheus.Labels{"pid": pid, "bin": binaryName, "name": descriptiveName},
 	})
-	pm.diskReadCountGauge = prometheus.NewGauge(prometheus.GaugeOpts{
+	pm.storagediskReadCountGauge = prometheus.NewGauge(prometheus.GaugeOpts{
 		Namespace:   metricNamespace,
-		Name:        "disk_reads",
-		Help:        "Total reads from disk",
+		Name:        "storage_reads",
+		Help:        "Total reads from storage",
 		ConstLabels: prometheus.Labels{"pid": pid, "bin": binaryName, "name": descriptiveName},
 	})
-	pm.diskWriteCountGauge = prometheus.NewGauge(prometheus.GaugeOpts{
+	pm.storageWriteCountGauge = prometheus.NewGauge(prometheus.GaugeOpts{
 		Namespace:   metricNamespace,
-		Name:        "disk_writes",
-		Help:        "Total writes to disk",
+		Name:        "storage_writes",
+		Help:        "Total writes to storage",
 		ConstLabels: prometheus.Labels{"pid": pid, "bin": binaryName, "name": descriptiveName},
 	})
 }
 
 func (pm *PrometheusProcessMetrics) Register() error {
-	registeredCollectors := make([]prometheus.Collector, 0)
+	pm.Unregister()
 	var err error
 	for _, collector := range []prometheus.Collector{
 		pm.cpuGauge,
 		pm.ramGauge,
 		pm.swapGauge,
-		pm.diskReadBytesGauge,
-		pm.diskWriteBytesGauge,
-		pm.diskReadCountGauge,
-		pm.diskWriteCountGauge,
+		pm.storageReadBytesGauge,
+		pm.storageWriteBytesGauge,
+		pm.storagediskReadCountGauge,
+		pm.storageWriteCountGauge,
 	} {
 		err = prometheus.Register(collector)
 		if err != nil {
 			break
 		}
-		registeredCollectors = append(registeredCollectors, collector)
+		pm.registeredCollectors = append(pm.registeredCollectors, collector)
 	}
 	if err != nil {
-		for _, collector := range registeredCollectors {
-			prometheus.Unregister(collector)
-		}
+		pm.Unregister()
 	}
 	return err
 }
 
 func (pm *PrometheusProcessMetrics) Unregister() {
-	prometheus.Unregister(pm.cpuGauge)
-}
-
-func (pm *PrometheusProcessMetrics) Update() {
-	prometheus.Unregister(pm.cpuGauge)
+	for _, collector := range pm.registeredCollectors {
+		prometheus.Unregister(collector)
+	}
+	pm.registeredCollectors = nil
 }
 
 func (pm *PrometheusProcessMetrics) Set(processMetrics *ProcessMetrics) {
 	if pm.previousMetrics != nil {
 		deltaTime := processMetrics.cpuSampleTime.Sub(pm.previousMetrics.cpuSampleTime).Seconds()
 		if deltaTime > 0 {
-			pm.cpuGauge.Set((processMetrics.cpuDuration - pm.previousMetrics.cpuDuration) / deltaTime)
+			pm.cpuGauge.Set(((processMetrics.cpuDuration - pm.previousMetrics.cpuDuration) * 100) / deltaTime)
 		} else {
 			log.Warn("deltaTime <= 0")
 		}
 	}
 	pm.ramGauge.Set(float64(processMetrics.ram))
 	pm.swapGauge.Set(float64(processMetrics.swap))
-	pm.diskReadBytesGauge.Set(float64(processMetrics.diskReadBytes))
-	pm.diskWriteBytesGauge.Set(float64(processMetrics.diskWriteBytes))
-	pm.diskReadCountGauge.Set(float64(processMetrics.diskReadCount))
-	pm.diskWriteCountGauge.Set(float64(processMetrics.diskWriteCount))
+	pm.storageReadBytesGauge.Set(float64(processMetrics.storageReadBytes))
+	pm.storageWriteBytesGauge.Set(float64(processMetrics.storageWriteBytes))
+	pm.storagediskReadCountGauge.Set(float64(processMetrics.storageReadCount))
+	pm.storageWriteCountGauge.Set(float64(processMetrics.storageWriteCount))
 	pm.previousMetrics = processMetrics
 }

cmd/exporter/metrics/prom_proc_metrics_set.go

@@ -108,7 +108,7 @@ func (set *PrometheusProcessMetricsSet) UpdateMetrics() {
 func updateMetrics(pm *PrometheusProcessMetrics, withPid int) {
 	processMetrics, err := getProcMetrics(withPid)
 	if err != nil {
-		log.Warn(fmt.Sprintf("Could not determine metrics for process %d: %v.", withPid, err))
+		log.Warn(fmt.Sprintf("Could not determy metrics for process %d: %v.", withPid, err))
 		return
 	}
 	pm.Set(processMetrics)
@@ -127,7 +127,10 @@ func procDescriptiveName(pid int, nameFlag string) (string, error) {
 }
 
 func descriptiveNameFromArgs(args []string, flagName string) (string, error) {
-	if len(args) <= 1 {
+	if len(args) == 0 {
+		return "", fmt.Errorf("no arguments")
+	}
+	if len(args) == 1 {
 		return "", fmt.Errorf("too few arguments")
 	}
 	args = args[1:]

integration_test/main.go

@@ -69,7 +69,7 @@ func main() {
 	lines := strings.Split(contentsString, "\n")
 	gotLine := false
 	for _, line := range lines {
-		prefix := fmt.Sprintf("mine_disk_write_bytes{bin=\"%s\",name=\"%s\",pid=\"%d\"} ", dummyBinaryName, dummyDescripiveName, cmdDummy.Process.Pid)
+		prefix := fmt.Sprintf("my_storage_write_bytes{bin=\"%s\",name=\"%s\",pid=\"%d\"} ", dummyBinaryName, dummyDescripiveName, cmdDummy.Process.Pid)
 		if strings.HasPrefix(line, prefix) {
 			writeBytes, err := strconv.Atoi(line[len(prefix):])
 			if err != nil {