main.go

package main

import (
	"context"
	"net/http"

	"github.com/draganm/missing-container-metrics/containerd"
	"github.com/draganm/missing-container-metrics/docker"
	"github.com/prometheus/client_golang/prometheus/promhttp"
	"github.com/urfave/cli/v2"
	"go.uber.org/zap"
)

var Version string

func main() {
	a := &cli.App{
		Flags: []cli.Flag{
			&cli.StringFlag{
				Name:  "bind-address",
				Value: ":3001",
				EnvVars: []string{
					"BIND_ADDRESS",
				},
			},
			&cli.BoolFlag{
				Name:  "docker",
				Value: true,
				EnvVars: []string{
					"DOCKER",
				},
			},
			&cli.BoolFlag{
				Name:  "containerd",
				Value: true,
				EnvVars: []string{
					"CONTAINERD",
				},
			},
		},
		Action: func(c *cli.Context) error {
			logger, err := zap.NewProduction()
			if err != nil {
				return err
			}

			slogger := logger.Sugar().With("version", Version)

			ctx, cancel := context.WithCancel(context.Background())
			defer cancel()

			if c.Bool("docker") {
				go func() {
					err := docker.HandleDocker(ctx, slogger)
					if err != nil {
						slogger.With("error", err).Error("while handling docker")
						cancel()
					}
				}()
			}

			if c.Bool("containerd") {
				go func() {
					err := containerd.HandleContainerd(ctx, slogger)
					if err != nil {
						slogger.With("error", err).Error("while handling containerd")
						cancel()
					}
				}()
			}

			slogger.Info("started")

			a := c.String("bind-address")

			mux := http.NewServeMux()
			mux.Handle("/metrics", promhttp.Handler())

			server := &http.Server{
				Addr:    a,
				Handler: mux,
			}

			// Close server when the context gets cancelled
			go func() {
				<-ctx.Done()
				server.Close()
			}()

			slogger.Infof("Listening on %s", a)
			return server.ListenAndServe()

		},
	}

	a.RunAndExitOnError()

}