Add documentation

collectors/collectorManager.go

@@ -34,17 +34,18 @@ var AvailableCollectors = map[string]MetricCollector{
 	"nfsstat":          new(NfsCollector),
 }
 
+// Metric collector manager data structure
 type collectorManager struct {
-	collectors []MetricCollector
-	output     chan lp.CCMetric // List of all output channels
+	collectors []MetricCollector          // List of metric collectors to use
+	output     chan lp.CCMetric           // Output channels
 	done       chan bool                  // channel to finish / stop metric collector manager
-	ticker     mct.MultiChanTicker
-	duration   time.Duration
-	wg         *sync.WaitGroup
-	config     map[string]json.RawMessage
+	ticker     mct.MultiChanTicker        // periodically ticking once each interval
+	duration   time.Duration              // duration (for metrics that measure over a given duration)
+	wg         *sync.WaitGroup            // wait group for all goroutines in cc-metric-collector
+	config     map[string]json.RawMessage // json encoded config for collector manager
 }
 
-// Metric collector access functions
+// Metric collector manager access functions
 type CollectorManager interface {
 	Init(ticker mct.MultiChanTicker, duration time.Duration, wg *sync.WaitGroup, collectConfigFile string) error
 	AddOutput(output chan lp.CCMetric)
@@ -53,9 +54,9 @@ type CollectorManager interface {
 }
 
 // Init initializes a new metric collector manager by setting up:
-// * output channels
+// * output channel
 // * done channel
-// * wait group synchronization (from variable wg)
+// * wait group synchronization for goroutines (from variable wg)
 // * ticker (from variable ticker)
 // * configuration (read from config file in variable collectConfigFile)
 // Initialization is done for all configured collectors
@@ -82,20 +83,20 @@ func (cm *collectorManager) Init(ticker mct.MultiChanTicker, duration time.Durat
 	}
 
 	// Initialize configured collectors
-	for k, cfg := range cm.config {
-		if _, found := AvailableCollectors[k]; !found {
-			cclog.ComponentError("CollectorManager", "SKIP unknown collector", k)
+	for collectorName, collectorCfg := range cm.config {
+		if _, found := AvailableCollectors[collectorName]; !found {
+			cclog.ComponentError("CollectorManager", "SKIP unknown collector", collectorName)
 			continue
 		}
-		c := AvailableCollectors[k]
+		collector := AvailableCollectors[collectorName]
 
-		err = c.Init(cfg)
+		err = collector.Init(collectorCfg)
 		if err != nil {
-			cclog.ComponentError("CollectorManager", "Collector", k, "initialization failed:", err.Error())
+			cclog.ComponentError("CollectorManager", "Collector", collectorName, "initialization failed:", err.Error())
 			continue
 		}
-		cclog.ComponentDebug("CollectorManager", "ADD COLLECTOR", c.Name())
-		cm.collectors = append(cm.collectors, c)
+		cclog.ComponentDebug("CollectorManager", "ADD COLLECTOR", collector.Name())
+		cm.collectors = append(cm.collectors, collector)
 	}
 	return nil
 }
@@ -157,7 +158,7 @@ func (cm *collectorManager) Close() {
 
 // New creates a new initialized metric collector manager
 func New(ticker mct.MultiChanTicker, duration time.Duration, wg *sync.WaitGroup, collectConfigFile string) (CollectorManager, error) {
-	cm := &collectorManager{}
+	cm := new(collectorManager)
 	err := cm.Init(ticker, duration, wg, collectConfigFile)
 	if err != nil {
 		return nil, err

internal/metricRouter/metricRouter.go

@@ -24,19 +24,20 @@ type metricRouterTagConfig struct {
 type metricRouterConfig struct {
 	AddTags       []metricRouterTagConfig `json:"add_tags"`           // List of tags that are added when the condition is met
 	DelTags       []metricRouterTagConfig `json:"delete_tags"`        // List of tags that are removed when the condition is met
-	IntervalStamp bool                    `json:"interval_timestamp"` // Update timestamp periodically?
+	IntervalStamp bool                    `json:"interval_timestamp"` // Update timestamp periodically by ticker each interval?
 }
 
+// Metric router data structure
 type metricRouter struct {
 	coll_input chan lp.CCMetric    // Input channel from CollectorManager
 	recv_input chan lp.CCMetric    // Input channel from ReceiveManager
 	outputs    []chan lp.CCMetric  // List of all output channels
 	done       chan bool           // channel to finish / stop metric router
-	wg         *sync.WaitGroup
-	timestamp  time.Time // timestamp
+	wg         *sync.WaitGroup     // wait group for all goroutines in cc-metric-collector
+	timestamp  time.Time           // timestamp periodically updated by ticker each interval
 	timerdone  chan bool           // channel to finish / stop timestamp updater
-	ticker     mct.MultiChanTicker
-	config     metricRouterConfig
+	ticker     mct.MultiChanTicker // periodically ticking once each interval
+	config     metricRouterConfig  // json encoded config for metric router
 }
 
 // MetricRouter access functions
@@ -60,6 +61,8 @@ func (r *metricRouter) Init(ticker mct.MultiChanTicker, wg *sync.WaitGroup, rout
 	r.done = make(chan bool)
 	r.wg = wg
 	r.ticker = ticker
+
+	// Read metric router config file
 	configFile, err := os.Open(routerConfigFile)
 	if err != nil {
 		cclog.ComponentError("MetricRouter", err.Error())
@@ -97,11 +100,11 @@ func (r *metricRouter) StartTimer() {
 	cclog.ComponentDebug("MetricRouter", "TIMER START")
 }
 
-// EvalCondition evaluates condition Cond for metric data from point
-func (r *metricRouter) EvalCondition(Cond string, point lp.CCMetric) (bool, error) {
-	expression, err := govaluate.NewEvaluableExpression(Cond)
+// EvalCondition evaluates condition cond for metric data from point
+func (r *metricRouter) EvalCondition(cond string, point lp.CCMetric) (bool, error) {
+	expression, err := govaluate.NewEvaluableExpression(cond)
 	if err != nil {
-		cclog.ComponentDebug("MetricRouter", Cond, " = ", err.Error())
+		cclog.ComponentDebug("MetricRouter", cond, " = ", err.Error())
 		return false, err
 	}
 
@@ -122,7 +125,7 @@ func (r *metricRouter) EvalCondition(Cond string, point lp.CCMetric) (bool, erro
 	// evaluate condition
 	result, err := expression.Evaluate(params)
 	if err != nil {
-		cclog.ComponentDebug("MetricRouter", Cond, " = ", err.Error())
+		cclog.ComponentDebug("MetricRouter", cond, " = ", err.Error())
 		return false, err
 	}
 	return bool(result.(bool)), err
@@ -172,13 +175,20 @@ func (r *metricRouter) DoDelTags(point lp.CCMetric) {
 
 // Start starts the metric router
 func (r *metricRouter) Start() {
+
+	// start timer if configured
 	r.timestamp = time.Now()
 	if r.config.IntervalStamp {
 		r.StartTimer()
 	}
+
+	// Router manager is done
 	done := func() {
 		cclog.ComponentDebug("MetricRouter", "DONE")
 	}
+
+	// Forward takes a received metric, adds or deletes tags
+	// and forwards it to the output channels
 	forward := func(point lp.CCMetric) {
 		cclog.ComponentDebug("MetricRouter", "FORWARD", point)
 		r.DoAddTags(point)
@@ -192,17 +202,20 @@ func (r *metricRouter) Start() {
 	go func() {
 		defer r.wg.Done()
 		for {
-			//		RouterLoop:
 			select {
 			case <-r.done:
 				done()
 				return
+
 			case p := <-r.coll_input:
+				// receive from metric collector
 				if r.config.IntervalStamp {
 					p.SetTime(r.timestamp)
 				}
 				forward(p)
+
 			case p := <-r.recv_input:
+				// receive from receive manager
 				if r.config.IntervalStamp {
 					p.SetTime(r.timestamp)
 				}
@@ -213,11 +226,12 @@ func (r *metricRouter) Start() {
 	cclog.ComponentDebug("MetricRouter", "STARTED")
 }
 
-// AddInput adds a input channel to the metric router
+// AddCollectorInput adds a channel between metric collector and metric router
 func (r *metricRouter) AddCollectorInput(input chan lp.CCMetric) {
 	r.coll_input = input
 }
 
+// AddReceiverInput adds a channel between metric receiver and metric router
 func (r *metricRouter) AddReceiverInput(input chan lp.CCMetric) {
 	r.recv_input = input
 }

sinks/sinkManager.go

@@ -9,21 +9,24 @@ import (
 	lp "github.com/ClusterCockpit/cc-metric-collector/internal/ccMetric"
 )
 
+// Map of all available sinks
 var AvailableSinks = map[string]Sink{
-	"influxdb": &InfluxSink{},
-	"stdout":   &StdoutSink{},
-	"nats":     &NatsSink{},
-	"http":     &HttpSink{},
+	"influxdb": new(InfluxSink),
+	"stdout":   new(StdoutSink),
+	"nats":     new(NatsSink),
+	"http":     new(HttpSink),
 }
 
+// Metric collector manager data structure
 type sinkManager struct {
-	input   chan lp.CCMetric
-	outputs []Sink
-	done    chan bool
-	wg      *sync.WaitGroup
-	config  []sinkConfig
+	input   chan lp.CCMetric // input channel
+	outputs []Sink           // List of sinks to use
+	done    chan bool        // channel to finish / stop metric sink manager
+	wg      *sync.WaitGroup  // wait group for all goroutines in cc-metric-collector
+	config  []sinkConfig     // json encoded config for sink manager
 }
 
+// Sink manager access functions
 type SinkManager interface {
 	Init(wg *sync.WaitGroup, sinkConfigFile string) error
 	AddInput(input chan lp.CCMetric)
@@ -38,6 +41,8 @@ func (sm *sinkManager) Init(wg *sync.WaitGroup, sinkConfigFile string) error {
 	sm.done = make(chan bool)
 	sm.wg = wg
 	sm.config = make([]sinkConfig, 0)
+
+	// Read sink config file
 	if len(sinkConfigFile) > 0 {
 		configFile, err := os.Open(sinkConfigFile)
 		if err != nil {
@@ -63,27 +68,36 @@ func (sm *sinkManager) Init(wg *sync.WaitGroup, sinkConfigFile string) error {
 }
 
 func (sm *sinkManager) Start() {
-	sm.wg.Add(1)
 	batchcount := 20
+
+	sm.wg.Add(1)
 	go func() {
+		defer sm.wg.Done()
+
+		// Sink manager is done
 		done := func() {
 			for _, s := range sm.outputs {
 				s.Flush()
 				s.Close()
 			}
-			sm.wg.Done()
+
 			cclog.ComponentDebug("SinkManager", "DONE")
 		}
+
 		for {
 			select {
 			case <-sm.done:
 				done()
 				return
+
 			case p := <-sm.input:
+				// Send received metric to all outputs
 				cclog.ComponentDebug("SinkManager", "WRITE", p)
 				for _, s := range sm.outputs {
 					s.Write(p)
 				}
+
+				// Flush all outputs
 				if batchcount == 0 {
 					cclog.ComponentDebug("SinkManager", "FLUSH")
 					for _, s := range sm.outputs {
@@ -95,9 +109,12 @@ func (sm *sinkManager) Start() {
 			}
 		}
 	}()
+
+	// Sink manager is started
 	cclog.ComponentDebug("SinkManager", "STARTED")
 }
 
+// AddInput adds the input channel to the sink manager
 func (sm *sinkManager) AddInput(input chan lp.CCMetric) {
 	sm.input = input
 }
@@ -128,11 +145,13 @@ func (sm *sinkManager) AddOutput(rawConfig json.RawMessage) error {
 	return nil
 }
 
+// Close finishes / stops the sink manager
 func (sm *sinkManager) Close() {
 	cclog.ComponentDebug("SinkManager", "CLOSE")
 	sm.done <- true
 }
 
+// New creates a new initialized sink manager
 func New(wg *sync.WaitGroup, sinkConfigFile string) (SinkManager, error) {
 	sm := &sinkManager{}
 	err := sm.Init(wg, sinkConfigFile)