Adding upstream version 1.34.4.

Signed-off-by: Daniel Baumann <daniel@debian.org>

plugins/common/docker/stats_helpers.go

@@ -0,0 +1,79 @@
+// Package docker contains few helper functions copied from
+// https://github.com/docker/cli/blob/master/cli/command/container/stats_helpers.go
+package docker
+
+import (
+	"github.com/docker/docker/api/types/container"
+)
+
+// CalculateCPUPercentUnix calculate CPU usage (for Unix, in percentages)
+func CalculateCPUPercentUnix(previousCPU, previousSystem uint64, v *container.StatsResponse) float64 {
+	var (
+		cpuPercent = 0.0
+		// calculate the change for the cpu usage of the container in between readings
+		cpuDelta = float64(v.CPUStats.CPUUsage.TotalUsage) - float64(previousCPU)
+		// calculate the change for the entire system between readings
+		systemDelta = float64(v.CPUStats.SystemUsage) - float64(previousSystem)
+		onlineCPUs  = float64(v.CPUStats.OnlineCPUs)
+	)
+
+	if onlineCPUs == 0.0 {
+		onlineCPUs = float64(len(v.CPUStats.CPUUsage.PercpuUsage))
+	}
+	if systemDelta > 0.0 && cpuDelta > 0.0 {
+		cpuPercent = (cpuDelta / systemDelta) * onlineCPUs * 100.0
+	}
+	return cpuPercent
+}
+
+// CalculateCPUPercentWindows calculate CPU usage (for Windows, in percentages)
+func CalculateCPUPercentWindows(v *container.StatsResponse) float64 {
+	// Max number of 100ns intervals between the previous time read and now
+	possIntervals := uint64(v.Read.Sub(v.PreRead).Nanoseconds()) // Start with number of ns intervals
+	possIntervals /= 100                                         // Convert to number of 100ns intervals
+	possIntervals *= uint64(v.NumProcs)                          // Multiple by the number of processors
+
+	// Intervals used
+	intervalsUsed := v.CPUStats.CPUUsage.TotalUsage - v.PreCPUStats.CPUUsage.TotalUsage
+
+	// Percentage avoiding divide-by-zero
+	if possIntervals > 0 {
+		return float64(intervalsUsed) / float64(possIntervals) * 100.0
+	}
+	return 0.00
+}
+
+// CalculateMemUsageUnixNoCache calculate memory usage of the container.
+// Cache is intentionally excluded to avoid misinterpretation of the output.
+//
+// On Docker 19.03 and older, the result is `mem.Usage - mem.Stats["cache"]`.
+// On new docker with cgroup v1 host, the result is `mem.Usage - mem.Stats["total_inactive_file"]`.
+// On new docker with cgroup v2 host, the result is `mem.Usage - mem.Stats["inactive_file"]`.
+//
+// This definition is designed to be consistent with past values and the latest docker CLI
+// * https://github.com/docker/cli/blob/6e2838e18645e06f3e4b6c5143898ccc44063e3b/cli/command/container/stats_helpers.go#L239
+func CalculateMemUsageUnixNoCache(mem container.MemoryStats) float64 {
+	// Docker 19.03 and older
+	if v, isOldDocker := mem.Stats["cache"]; isOldDocker && v < mem.Usage {
+		return float64(mem.Usage - v)
+	}
+	// cgroup v1
+	if v, isCgroup1 := mem.Stats["total_inactive_file"]; isCgroup1 && v < mem.Usage {
+		return float64(mem.Usage - v)
+	}
+	// cgroup v2
+	if v := mem.Stats["inactive_file"]; v < mem.Usage {
+		return float64(mem.Usage - v)
+	}
+	return float64(mem.Usage)
+}
+
+// CalculateMemPercentUnixNoCache calculate memory usage of the container, in percentages.
+func CalculateMemPercentUnixNoCache(limit, usedNoCache float64) float64 {
+	// MemoryStats.Limit will never be 0 unless the container is not running and we haven't
+	// got any data from cgroup
+	if limit != 0 {
+		return usedNoCache / limit * 100.0
+	}
+	return 0
+}