dockerAPI.go

package main

import (
	"context"

	"github.com/docker/docker/api/types"
	"github.com/docker/docker/api/types/events"
	"github.com/docker/docker/client"
	"github.com/fasibio/funk_agent/logger"
)

// DockerClient represent all used methods from docker client
type DockerClient interface {
	ContainerList(ctx context.Context, options types.ContainerListOptions) ([]types.Container, error)
	Info(ctx context.Context) (types.Info, error)
	Events(ctx context.Context, options types.EventsOptions) (<-chan events.Message, <-chan error)
}

func getTrackingContainer(ctx context.Context, cli DockerClient) ([]types.Container, error) {
	c, err := cli.ContainerList(ctx, types.ContainerListOptions{All: false})

	if err != nil {
		return nil, err
	}

	var res []types.Container
	for _, one := range c {
		if one.Labels["funk.log"] == "false" {
			continue
		} else {
			res = append(res, one)
		}
	}
	return res, nil
}

// StartListeningForContainer start the dockercontainerwatcher in an own goroutine. It will returns the docker client and metainfos
func StartListeningForContainer(ctx context.Context, trackingContainer chan []types.Container) (*client.Client, *types.Info, error) {

	cli, err := client.NewEnvClient()
	if err != nil {
		return nil, nil, err
	}

	res, err := getTrackingContainer(ctx, cli)
	if err != nil {
		logger.Get().Errorw("Error by getTrackingContainer: " + err.Error())
	} else {
		trackingContainer <- res
	}
	info, err := cli.Info(ctx)

	if err != nil {
		return nil, nil, err
	}
	msg, errs := cli.Events(ctx, types.EventsOptions{})
	go func() {
		for e := range errs {
			logger.Get().Errorw("Error by Events: " + e.Error())
		}
	}()

	go readMessages(ctx, cli, msg, trackingContainer)
	return cli, &info, nil
}

func readMessages(ctx context.Context, cli DockerClient, msg <-chan events.Message, trackingContainer chan []types.Container) {
	for m := range msg {
		if m.Type == "container" {
			res, err := getTrackingContainer(ctx, cli)
			if err != nil {
				logger.Get().Errorw("Error by getTrackingContainer: " + err.Error())
				continue
			}
			trackingContainer <- res
		}
	}
}