Merge pull request #673 from miketonks/f-docker-percentages

Add calculated cpu and memory percentages to docker input (via config option)

plugins/inputs/docker/docker.go

@@ -67,6 +67,7 @@ func (d *Docker) Gather(acc telegraf.Accumulator) error {
 	var wg sync.WaitGroup
 	wg.Add(len(containers))
 	for _, container := range containers {
+
 		go func(c docker.APIContainers) {
 			defer wg.Done()
 			err := d.gatherContainer(c, acc)
@@ -177,6 +178,7 @@ func gatherContainerStats(
 		"pgfault":                   stat.MemoryStats.Stats.Pgfault,
 		"inactive_file":             stat.MemoryStats.Stats.InactiveFile,
 		"total_pgpgin":              stat.MemoryStats.Stats.TotalPgpgin,
+		"usage_percent":             calculateMemPercent(stat),
 	}
 	acc.AddFields("docker_mem", memfields, tags, now)
 
@@ -188,6 +190,7 @@ func gatherContainerStats(
 		"throttling_periods":           stat.CPUStats.ThrottlingData.Periods,
 		"throttling_throttled_periods": stat.CPUStats.ThrottlingData.ThrottledPeriods,
 		"throttling_throttled_time":    stat.CPUStats.ThrottlingData.ThrottledTime,
+		"usage_percent":                calculateCPUPercent(stat),
 	}
 	cputags := copyTags(tags)
 	cputags["cpu"] = "cpu-total"
@@ -219,6 +222,26 @@ func gatherContainerStats(
 	gatherBlockIOMetrics(stat, acc, tags, now)
 }
 
+func calculateMemPercent(stat *docker.Stats) float64 {
+	var memPercent = 0.0
+	if stat.MemoryStats.Limit > 0 {
+		memPercent = float64(stat.MemoryStats.Usage) / float64(stat.MemoryStats.Limit) * 100.0
+	}
+	return memPercent
+}
+
+func calculateCPUPercent(stat *docker.Stats) float64 {
+	var cpuPercent = 0.0
+	// calculate the change for the cpu and system usage of the container in between readings
+	cpuDelta := float64(stat.CPUStats.CPUUsage.TotalUsage) - float64(stat.PreCPUStats.CPUUsage.TotalUsage)
+	systemDelta := float64(stat.CPUStats.SystemCPUUsage) - float64(stat.PreCPUStats.SystemCPUUsage)
+
+	if systemDelta > 0.0 && cpuDelta > 0.0 {
+		cpuPercent = (cpuDelta / systemDelta) * float64(len(stat.CPUStats.CPUUsage.PercpuUsage)) * 100.0
+	}
+	return cpuPercent
+}
+
 func gatherBlockIOMetrics(
 	stat *docker.Stats,
 	acc telegraf.Accumulator,

plugins/inputs/docker/docker_test.go

@@ -49,7 +49,7 @@ func TestDockerGatherContainerStats(t *testing.T) {
 		"max_usage":                 uint64(1001),
 		"usage":                     uint64(1111),
 		"fail_count":                uint64(1),
-		"limit":                     uint64(20),
+		"limit":                     uint64(2000),
 		"total_pgmafault":           uint64(0),
 		"cache":                     uint64(0),
 		"mapped_file":               uint64(0),
@@ -79,7 +79,9 @@ func TestDockerGatherContainerStats(t *testing.T) {
 		"pgfault":                   uint64(2),
 		"inactive_file":             uint64(3),
 		"total_pgpgin":              uint64(4),
+		"usage_percent":             float64(55.55),
 	}
+
 	acc.AssertContainsTaggedFields(t, "docker_mem", memfields, tags)
 
 	// test docker_cpu measurement
@@ -93,6 +95,7 @@ func TestDockerGatherContainerStats(t *testing.T) {
 		"throttling_periods":           uint64(1),
 		"throttling_throttled_periods": uint64(0),
 		"throttling_throttled_time":    uint64(0),
+		"usage_percent":                float64(400.0),
 	}
 	acc.AssertContainsTaggedFields(t, "docker_cpu", cpufields, cputags)
 
@@ -122,6 +125,9 @@ func testStats() *docker.Stats {
 	stats.CPUStats.SystemCPUUsage = 100
 	stats.CPUStats.ThrottlingData.Periods = 1
 
+	stats.PreCPUStats.CPUUsage.TotalUsage = 400
+	stats.PreCPUStats.SystemCPUUsage = 50
+
 	stats.MemoryStats.Stats.TotalPgmafault = 0
 	stats.MemoryStats.Stats.Cache = 0
 	stats.MemoryStats.Stats.MappedFile = 0
@@ -155,7 +161,7 @@ func testStats() *docker.Stats {
 	stats.MemoryStats.MaxUsage = 1001
 	stats.MemoryStats.Usage = 1111
 	stats.MemoryStats.Failcnt = 1
-	stats.MemoryStats.Limit = 20
+	stats.MemoryStats.Limit = 2000
 
 	stats.Networks["eth0"] = docker.NetworkStats{
 		RxDropped: 1,