Collector-specific configuration. LIKWID collector derives metrics itself, Run once CLI option

collectors/diskstatMetric.go

@@ -1,28 +1,42 @@
 package collectors
 
 import (
-	//	"errors"
-	//	"fmt"
 	lp "github.com/influxdata/line-protocol"
 	"io/ioutil"
-	"log"
+//	"log"
 	"strconv"
 	"strings"
 	"time"
+	"encoding/json"
+	"errors"
 )
 
 const DISKSTATFILE = `/proc/diskstats`
+const DISKSTAT_SYSFSPATH = `/sys/block`
+
+type DiskstatCollectorConfig struct {
+    ExcludeMetrics []string                 `json:"exclude_metrics, omitempty"`
+}
 
 type DiskstatCollector struct {
 	MetricCollector
 	matches map[int]string
+	config DiskstatCollectorConfig
 }
 
-func (m *DiskstatCollector) Init() error {
+
+func (m *DiskstatCollector) Init(config []byte) error {
+    var err error
 	m.name = "DiskstatCollector"
 	m.setup()
+	if len(config) > 0 {
+	    err = json.Unmarshal(config, &m.config)
+	    if err != nil {
+	        return err
+	    }
+	}
 	// https://www.kernel.org/doc/html/latest/admin-guide/iostats.html
-	m.matches = map[int]string{
+	matches := map[int]string{
 		3:  "reads",
 		4:  "reads_merged",
 		5:  "read_sectors",
@@ -41,46 +55,60 @@ func (m *DiskstatCollector) Init() error {
 		18: "flushes",
 		19: "flushes_ms",
 	}
-	_, err := ioutil.ReadFile(string(DISKSTATFILE))
-	if err == nil {
-		m.init = true
+	m.matches = make(map[int]string)
+	for k, v := range matches {
+	    _, skip := stringArrayContains(m.config.ExcludeMetrics, v)
+	    if (!skip) {
+	        m.matches[k] = v
+	    }
 	}
+	if len(m.matches) == 0 {
+	    return errors.New("No metrics to collect")
+	}
+	_, err = ioutil.ReadFile(string(DISKSTATFILE))
+    if err == nil {
+	    m.init = true
+    }
 	return err
 }
 
+
 func (m *DiskstatCollector) Read(interval time.Duration, out *[]lp.MutableMetric) {
+    var lines []string
+    if !m.init {
+        return
+    }
 
-	buffer, err := ioutil.ReadFile(string(DISKSTATFILE))
+    buffer, err := ioutil.ReadFile(string(DISKSTATFILE))
+    if err != nil {
+        return
+    }
+    lines = strings.Split(string(buffer), "\n")
 
-	if err != nil {
-		log.Print(err)
-		return
-	}
-
-	ll := strings.Split(string(buffer), "\n")
-
-	for _, line := range ll {
-		if len(line) == 0 {
-			continue
-		}
-		f := strings.Fields(line)
-		if strings.Contains(f[2], "loop") {
-			continue
-		}
-		tags := map[string]string{
-			"device": f[2],
-			"type":   "node",
-		}
-		for idx, name := range m.matches {
-			x, err := strconv.ParseInt(f[idx], 0, 64)
-			if err == nil {
-				y, err := lp.New(name, tags, map[string]interface{}{"value": int(x)}, time.Now())
-				if err == nil {
-					*out = append(*out, y)
-				}
-			}
-		}
-	}
+    for _, line := range lines {
+	    if len(line) == 0 {
+		    continue
+	    }
+	    f := strings.Fields(line)
+	    if strings.Contains(f[2], "loop") {
+		    continue
+	    }
+	    tags := map[string]string{
+		    "device": f[2],
+		    "type":   "node",
+	    }
+	    for idx, name := range m.matches {
+	        if idx < len(f) {
+		        x, err := strconv.ParseInt(f[idx], 0, 64)
+		        if err == nil {
+			        y, err := lp.New(name, tags, map[string]interface{}{"value": int(x)}, time.Now())
+			        if err == nil {
+				        *out = append(*out, y)
+			        }
+		        }
+		    }
+	    }
+    }
 	return
 }