further collector refactoring, add logging to metrics subpackage

container.go

@@ -28,7 +28,6 @@ func (c *Container) SetState(s string) {
 
 // Read metric stream, updating widgets
 func (c *Container) Read(stream chan metrics.Metrics) {
-	log.Infof("starting reader for container: %s", c.id)
 	go func() {
 		for metrics := range stream {
 			c.metrics = metrics
@@ -36,5 +35,7 @@ func (c *Container) Read(stream chan metrics.Metrics) {
 			c.widgets.SetMem(metrics.MemUsage, metrics.MemLimit, metrics.MemPercent)
 			c.widgets.SetNet(metrics.NetRx, metrics.NetTx)
 		}
+		log.Infof("reader stopped for container: %s", c.id)
 	}()
+	log.Infof("reader started for container: %s", c.id)
 }

containermap.go

@@ -55,9 +55,14 @@ func (cm *ContainerMap) Refresh() {
 			}
 		}
 
+		if _, ok := cm.collectors[id]; ok == false {
+			cm.collectors[id] = metrics.NewDocker(cm.client, id)
+		}
+
 	}
 
 	var removeIDs []string
+	var collectIDs []string
 	for id, c := range cm.containers {
 		// mark stale internal containers
 		if _, ok := states[id]; ok == false {
@@ -67,16 +72,19 @@ func (cm *ContainerMap) Refresh() {
 		c.SetState(states[id])
 		// start collector if needed
 		if c.state == "running" {
-			if _, ok := cm.collectors[id]; ok == false {
-				log.Infof("starting collector for container: %s", id)
-				cm.collectors[id] = metrics.NewDocker(cm.client, id)
-				cm.collectors[id].Start()
-				c.Read(cm.collectors[id].Stream())
-			}
+			collectIDs = append(collectIDs, id)
 		}
 	}
 
-	// remove dead containers
+	for _, id := range collectIDs {
+		if !cm.collectors[id].Running() {
+			cm.collectors[id].Start()
+			stream := cm.collectors[id].Stream()
+			cm.containers[id].Read(stream)
+		}
+	}
+
+	// delete removed containers
 	cm.Del(removeIDs...)
 }
 
@@ -103,6 +111,7 @@ func (cm *ContainerMap) Get(id string) *Container {
 func (cm *ContainerMap) Del(ids ...string) {
 	for _, id := range ids {
 		delete(cm.containers, id)
+		delete(cm.collectors, id)
 	}
 }
 

metrics/docker.go

@@ -21,12 +21,12 @@ func NewDocker(client *api.Client, id string) *Docker {
 		Metrics: Metrics{},
 		id:      id,
 		client:  client,
-		stream:  make(chan Metrics),
-		done:    make(chan bool),
 	}
 }
 
 func (c *Docker) Start() {
+	c.done = make(chan bool)
+	c.stream = make(chan Metrics)
 	stats := make(chan *api.Stats)
 
 	go func() {
@@ -48,9 +48,11 @@ func (c *Docker) Start() {
 			c.ReadNet(s)
 			c.stream <- c.Metrics
 		}
+		log.Infof("collector stopped for container: %s", c.id)
 	}()
 
 	c.running = true
+	log.Infof("collector started for container: %s", c.id)
 }
 
 func (c *Docker) Running() bool {

metrics/main.go

@@ -2,8 +2,12 @@ package metrics
 
 import (
 	"math"
+
+	"github.com/bcicen/ctop/logging"
 )
 
+var log = logging.Init()
+
 type Metrics struct {
 	CPUUtil    int
 	NetTx      int64