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

collectors/memstatMetric.go

@@ -9,22 +9,36 @@ import (
 	"strconv"
 	"strings"
 	"time"
+	"encoding/json"
 )
 
 const MEMSTATFILE = `/proc/meminfo`
 
+type MemstatCollectorConfig struct {
+    ExcludeMetrics []string                 `json:"exclude_metrics"`
+}
+
 type MemstatCollector struct {
 	MetricCollector
 	stats   map[string]int64
 	tags    map[string]string
 	matches map[string]string
+	config MemstatCollectorConfig
 }
 
-func (m *MemstatCollector) Init() error {
+func (m *MemstatCollector) Init(config []byte) error {
+    var err error
 	m.name = "MemstatCollector"
+	if len(config) > 0 {
+	    err = json.Unmarshal(config, &m.config)
+	    if err != nil {
+	        return err
+	    }
+	}
 	m.stats = make(map[string]int64)
+	m.matches = make(map[string]string)
 	m.tags = map[string]string{"type": "node"}
-	m.matches = map[string]string{`MemTotal`: "mem_total",
+	matches := map[string]string{`MemTotal`: "mem_total",
 		"SwapTotal":    "swap_total",
 		"SReclaimable": "mem_sreclaimable",
 		"Slab":         "mem_slab",
@@ -33,8 +47,17 @@ func (m *MemstatCollector) Init() error {
 		"Cached":       "mem_cached",
 		"MemAvailable": "mem_available",
 		"SwapFree":     "swap_free"}
+	for k, v := range matches {
+	    _, skip := stringArrayContains(m.config.ExcludeMetrics, k)
+	    if (!skip) {
+	        m.matches[k] = v
+	    }
+	}
+	if len(m.matches) == 0 {
+	    return errors.New("No metrics to collect")
+	}
 	m.setup()
-	_, err := ioutil.ReadFile(string(MEMSTATFILE))
+	_, err = ioutil.ReadFile(string(MEMSTATFILE))
 	if err == nil {
 		m.init = true
 	}
@@ -42,15 +65,17 @@ func (m *MemstatCollector) Init() error {
 }
 
 func (m *MemstatCollector) Read(interval time.Duration, out *[]lp.MutableMetric) {
-	buffer, err := ioutil.ReadFile(string(MEMSTATFILE))
+    if !m.init {
+        return
+    }
 
+	buffer, err := ioutil.ReadFile(string(MEMSTATFILE))
 	if err != nil {
 		log.Print(err)
 		return
 	}
 
 	ll := strings.Split(string(buffer), "\n")
-
 	for _, line := range ll {
 		ls := strings.Split(line, `:`)
 		if len(ls) > 1 {
@@ -81,16 +106,18 @@ func (m *MemstatCollector) Read(interval time.Duration, out *[]lp.MutableMetric)
 		if _, buffers := m.stats[`Buffers`]; buffers {
 			if _, cached := m.stats[`Cached`]; cached {
 				memUsed := m.stats[`MemTotal`] - (m.stats[`MemFree`] + m.stats[`Buffers`] + m.stats[`Cached`])
+				_, skip := stringArrayContains(m.config.ExcludeMetrics, "mem_used")
 				y, err := lp.New("mem_used", m.tags, map[string]interface{}{"value": int(float64(memUsed) * 1.0e-3)}, time.Now())
-				if err == nil {
+				if err == nil && !skip {
 					*out = append(*out, y)
 				}
 			}
 		}
 	}
 	if _, found := m.stats[`MemShared`]; found {
+	    _, skip := stringArrayContains(m.config.ExcludeMetrics, "mem_shared")
 		y, err := lp.New("mem_shared", m.tags, map[string]interface{}{"value": int(float64(m.stats[`MemShared`]) * 1.0e-3)}, time.Now())
-		if err == nil {
+		if err == nil && !skip {
 			*out = append(*out, y)
 		}
 	}