Initial version

Author: David Currie

Dockerfile

@@ -0,0 +1,3 @@
+FROM scratch
+COPY cpu-usage /cpu-usage
+CMD ["/cpu-usage"]

usage.go

@@ -0,0 +1,56 @@
+package main
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"io/ioutil"
+	"strings"
+	"time"
+
+	"github.com/docker/docker/api/types"
+	"github.com/docker/docker/client"
+)
+
+func main() {
+	cli, err := client.NewClient("unix:///var/run/docker.sock", "", nil, nil) 
+	if err != nil {
+		panic(err)
+	}
+	containers, err := cli.ContainerList(context.Background(), types.ContainerListOptions{})
+	if err != nil {
+		panic(err)
+	}
+
+	for _, container := range containers {
+		if strings.HasSuffix(container.Image, "cpu-usage") {
+			continue
+		}
+		inspect, err := cli.ContainerInspect(context.Background(), container.ID)
+		if err != nil {
+			panic(err)
+		}
+		started, err := time.Parse(time.RFC3339Nano, inspect.State.StartedAt)
+		if err != nil {
+			panic(err)
+		}
+		resp, err := cli.ContainerStats(context.Background(), container.ID, false)
+		if err != nil {
+			panic(err)
+		}
+		defer resp.Body.Close()
+		content, err := ioutil.ReadAll(resp.Body)
+		if err != nil {
+			panic(err)
+		}
+		var stats types.StatsJSON
+		err = json.Unmarshal(content, &stats)
+		if err != nil {
+			panic(err)
+		}
+		usage := time.Duration(stats.Stats.CPUStats.CPUUsage.TotalUsage)*time.Nanosecond
+		read := stats.Stats.Read
+		elapsed := read.Sub(started)
+		fmt.Printf("%s - CPU: %s Elapsed: %s\n", container.Names[0][1:], usage, elapsed)
+	}
+}