package main

import (
	"context"
	"crypto/tls"
	"fmt"
	"os"
	"path/filepath"
	"strings"
	"time"

	"github.com/Sirupsen/logrus"
	"github.com/docker/distribution/uuid"
	"github.com/docker/docker/api"
	apiserver "github.com/docker/docker/api/server"
	buildbackend "github.com/docker/docker/api/server/backend/build"
	"github.com/docker/docker/api/server/middleware"
	"github.com/docker/docker/api/server/router"
	"github.com/docker/docker/api/server/router/build"
	checkpointrouter "github.com/docker/docker/api/server/router/checkpoint"
	"github.com/docker/docker/api/server/router/container"
	distributionrouter "github.com/docker/docker/api/server/router/distribution"
	"github.com/docker/docker/api/server/router/image"
	"github.com/docker/docker/api/server/router/network"
	pluginrouter "github.com/docker/docker/api/server/router/plugin"
	swarmrouter "github.com/docker/docker/api/server/router/swarm"
	systemrouter "github.com/docker/docker/api/server/router/system"
	"github.com/docker/docker/api/server/router/volume"
	"github.com/docker/docker/cli/debug"
	"github.com/docker/docker/daemon"
	"github.com/docker/docker/daemon/cluster"
	"github.com/docker/docker/daemon/config"
	"github.com/docker/docker/daemon/logger"
	"github.com/docker/docker/dockerversion"
	"github.com/docker/docker/libcontainerd"
	dopts "github.com/docker/docker/opts"
	"github.com/docker/docker/pkg/authorization"
	"github.com/docker/docker/pkg/jsonlog"
	"github.com/docker/docker/pkg/listeners"
	"github.com/docker/docker/pkg/pidfile"
	"github.com/docker/docker/pkg/plugingetter"
	"github.com/docker/docker/pkg/signal"
	"github.com/docker/docker/plugin"
	"github.com/docker/docker/registry"
	"github.com/docker/docker/runconfig"
	"github.com/docker/go-connections/tlsconfig"
	swarmapi "github.com/docker/swarmkit/api"
	"github.com/spf13/pflag"
)

// DaemonCli represents the daemon CLI.
type DaemonCli struct {
	*config.Config
	configFile *string
	flags      *pflag.FlagSet

	api             *apiserver.Server
	d               *daemon.Daemon
	authzMiddleware *authorization.Middleware // authzMiddleware enables to dynamically reload the authorization plugins
}

// NewDaemonCli returns a daemon CLI
func NewDaemonCli() *DaemonCli {
	return &DaemonCli{}
}

func (cli *DaemonCli) start(opts *daemonOptions) (err error) {
	stopc := make(chan bool)
	defer close(stopc)

	// warn from uuid package when running the daemon
	uuid.Loggerf = logrus.Warnf

	opts.SetDefaultOptions(opts.flags)

	if cli.Config, err = loadDaemonCliConfig(opts); err != nil {
		return err
	}
	cli.configFile = &opts.configFile
	cli.flags = opts.flags

	if cli.Config.Debug {
		debug.Enable()
	}

	if cli.Config.Experimental {
		logrus.Warn("Running experimental build")
	}

	logrus.SetFormatter(&logrus.TextFormatter{
		TimestampFormat: jsonlog.RFC3339NanoFixed,
		DisableColors:   cli.Config.RawLogs,
	})

	if err := setDefaultUmask(); err != nil {
		return fmt.Errorf("Failed to set umask: %v", err)
	}

	if len(cli.LogConfig.Config) > 0 {
		if err := logger.ValidateLogOpts(cli.LogConfig.Type, cli.LogConfig.Config); err != nil {
			return fmt.Errorf("Failed to set log opts: %v", err)
		}
	}

	// Create the daemon root before we create ANY other files (PID, or migrate keys)
	// to ensure the appropriate ACL is set (particularly relevant on Windows)
	if err := daemon.CreateDaemonRoot(cli.Config); err != nil {
		return err
	}

	if cli.Pidfile != "" {
		pf, err := pidfile.New(cli.Pidfile)
		if err != nil {
			return fmt.Errorf("Error starting daemon: %v", err)
		}
		defer func() {
			if err := pf.Remove(); err != nil {
				logrus.Error(err)
			}
		}()
	}

	serverConfig := &apiserver.Config{
		Logging:     true,
		SocketGroup: cli.Config.SocketGroup,
		Version:     dockerversion.Version,
		EnableCors:  cli.Config.EnableCors,
		CorsHeaders: cli.Config.CorsHeaders,
	}

	if cli.Config.TLS {
		tlsOptions := tlsconfig.Options{
			CAFile:             cli.Config.CommonTLSOptions.CAFile,
			CertFile:           cli.Config.CommonTLSOptions.CertFile,
			KeyFile:            cli.Config.CommonTLSOptions.KeyFile,
			ExclusiveRootPools: true,
		}

		if cli.Config.TLSVerify {
			// server requires and verifies client's certificate
			tlsOptions.ClientAuth = tls.RequireAndVerifyClientCert
		}
		tlsConfig, err := tlsconfig.Server(tlsOptions)
		if err != nil {
			return err
		}
		serverConfig.TLSConfig = tlsConfig
	}

	if len(cli.Config.Hosts) == 0 {
		cli.Config.Hosts = make([]string, 1)
	}

	api := apiserver.New(serverConfig)
	cli.api = api

	var hosts []string

	for i := 0; i < len(cli.Config.Hosts); i++ {
		var err error
		if cli.Config.Hosts[i], err = dopts.ParseHost(cli.Config.TLS, cli.Config.Hosts[i]); err != nil {
			return fmt.Errorf("error parsing -H %s : %v", cli.Config.Hosts[i], err)
		}

		protoAddr := cli.Config.Hosts[i]
		protoAddrParts := strings.SplitN(protoAddr, "://", 2)
		if len(protoAddrParts) != 2 {
			return fmt.Errorf("bad format %s, expected PROTO://ADDR", protoAddr)
		}

		proto := protoAddrParts[0]
		addr := protoAddrParts[1]

		// It's a bad idea to bind to TCP without tlsverify.
		if proto == "tcp" && (serverConfig.TLSConfig == nil || serverConfig.TLSConfig.ClientAuth != tls.RequireAndVerifyClientCert) {
			logrus.Warn("[!] DON'T BIND ON ANY IP ADDRESS WITHOUT setting --tlsverify IF YOU DON'T KNOW WHAT YOU'RE DOING [!]")
		}
		ls, err := listeners.Init(proto, addr, serverConfig.SocketGroup, serverConfig.TLSConfig)
		if err != nil {
			return err
		}
		ls = wrapListeners(proto, ls)
		// If we're binding to a TCP port, make sure that a container doesn't try to use it.
		if proto == "tcp" {
			if err := allocateDaemonPort(addr); err != nil {
				return err
			}
		}
		logrus.Debugf("Listener created for HTTP on %s (%s)", proto, addr)
		hosts = append(hosts, protoAddrParts[1])
		api.Accept(addr, ls...)
	}

	registryService := registry.NewService(cli.Config.ServiceOptions)
	containerdRemote, err := libcontainerd.New(cli.getLibcontainerdRoot(), cli.getPlatformRemoteOptions()...)
	if err != nil {
		return err
	}
	signal.Trap(func() {
		cli.stop()
		<-stopc // wait for daemonCli.start() to return
	})

	// Notify that the API is active, but before daemon is set up.
	preNotifySystem()

	pluginStore := plugin.NewStore()

	if err := cli.initMiddlewares(api, serverConfig, pluginStore); err != nil {
		logrus.Fatalf("Error creating middlewares: %v", err)
	}

	d, err := daemon.NewDaemon(cli.Config, registryService, containerdRemote, pluginStore)
	if err != nil {
		return fmt.Errorf("Error starting daemon: %v", err)
	}

	d.StoreHosts(hosts)

	// validate after NewDaemon has restored enabled plugins. Dont change order.
	if err := validateAuthzPlugins(cli.Config.AuthorizationPlugins, pluginStore); err != nil {
		return fmt.Errorf("Error validating authorization plugin: %v", err)
	}

	if cli.Config.MetricsAddress != "" {
		if !d.HasExperimental() {
			return fmt.Errorf("metrics-addr is only supported when experimental is enabled")
		}
		if err := startMetricsServer(cli.Config.MetricsAddress); err != nil {
			return err
		}
	}

	name, _ := os.Hostname()

	// Use a buffered channel to pass changes from store watch API to daemon
	// A buffer allows store watch API and daemon processing to not wait for each other
	watchStream := make(chan *swarmapi.WatchMessage, 32)

	c, err := cluster.New(cluster.Config{
		Root:                   cli.Config.Root,
		Name:                   name,
		Backend:                d,
		NetworkSubnetsProvider: d,
		DefaultAdvertiseAddr:   cli.Config.SwarmDefaultAdvertiseAddr,
		RuntimeRoot:            cli.getSwarmRunRoot(),
		WatchStream:            watchStream,
	})
	if err != nil {
		logrus.Fatalf("Error creating cluster component: %v", err)
	}
	d.SetCluster(c)
	err = c.Start()
	if err != nil {
		logrus.Fatalf("Error starting cluster component: %v", err)
	}

	// Restart all autostart containers which has a swarm endpoint
	// and is not yet running now that we have successfully
	// initialized the cluster.
	d.RestartSwarmContainers()

	logrus.Info("Daemon has completed initialization")

	logrus.WithFields(logrus.Fields{
		"version":     dockerversion.Version,
		"commit":      dockerversion.GitCommit,
		"graphdriver": d.GraphDriverName(),
	}).Info("Docker daemon")

	cli.d = d

	initRouter(api, d, c)

	// process cluster change notifications
	watchCtx, cancel := context.WithCancel(context.Background())
	defer cancel()
	go d.ProcessClusterNotifications(watchCtx, watchStream)

	cli.setupConfigReloadTrap()

	// The serve API routine never exits unless an error occurs
	// We need to start it as a goroutine and wait on it so
	// daemon doesn't exit
	serveAPIWait := make(chan error)
	go api.Wait(serveAPIWait)

	// after the daemon is done setting up we can notify systemd api
	notifySystem()

	// Daemon is fully initialized and handling API traffic
	// Wait for serve API to complete
	errAPI := <-serveAPIWait
	c.Cleanup()
	shutdownDaemon(d)
	containerdRemote.Cleanup()
	if errAPI != nil {
		return fmt.Errorf("Shutting down due to ServeAPI error: %v", errAPI)
	}

	return nil
}

func (cli *DaemonCli) reloadConfig() {
	reload := func(config *config.Config) {

		// Revalidate and reload the authorization plugins
		if err := validateAuthzPlugins(config.AuthorizationPlugins, cli.d.PluginStore); err != nil {
			logrus.Fatalf("Error validating authorization plugin: %v", err)
			return
		}
		cli.authzMiddleware.SetPlugins(config.AuthorizationPlugins)

		if err := cli.d.Reload(config); err != nil {
			logrus.Errorf("Error reconfiguring the daemon: %v", err)
			return
		}

		if config.IsValueSet("debug") {
			debugEnabled := debug.IsEnabled()
			switch {
			case debugEnabled && !config.Debug: // disable debug
				debug.Disable()
				cli.api.DisableProfiler()
			case config.Debug && !debugEnabled: // enable debug
				debug.Enable()
				cli.api.EnableProfiler()
			}

		}
	}

	if err := config.Reload(*cli.configFile, cli.flags, reload); err != nil {
		logrus.Error(err)
	}
}

func (cli *DaemonCli) stop() {
	cli.api.Close()
}

// shutdownDaemon just wraps daemon.Shutdown() to handle a timeout in case
// d.Shutdown() is waiting too long to kill container or worst it's
// blocked there
func shutdownDaemon(d *daemon.Daemon) {
	shutdownTimeout := d.ShutdownTimeout()
	ch := make(chan struct{})
	go func() {
		d.Shutdown()
		close(ch)
	}()
	if shutdownTimeout < 0 {
		<-ch
		logrus.Debug("Clean shutdown succeeded")
		return
	}
	select {
	case <-ch:
		logrus.Debug("Clean shutdown succeeded")
	case <-time.After(time.Duration(shutdownTimeout) * time.Second):
		logrus.Error("Force shutdown daemon")
	}
}

func loadDaemonCliConfig(opts *daemonOptions) (*config.Config, error) {
	conf := opts.daemonConfig
	flags := opts.flags
	conf.Debug = opts.Debug
	conf.Hosts = opts.Hosts
	conf.LogLevel = opts.LogLevel
	conf.TLS = opts.TLS
	conf.TLSVerify = opts.TLSVerify
	conf.CommonTLSOptions = config.CommonTLSOptions{}

	if opts.TLSOptions != nil {
		conf.CommonTLSOptions.CAFile = opts.TLSOptions.CAFile
		conf.CommonTLSOptions.CertFile = opts.TLSOptions.CertFile
		conf.CommonTLSOptions.KeyFile = opts.TLSOptions.KeyFile
	}

	if conf.TrustKeyPath == "" {
		conf.TrustKeyPath = filepath.Join(
			getDaemonConfDir(conf.Root),
			defaultTrustKeyFile)
	}

	if flags.Changed("graph") && flags.Changed("data-root") {
		return nil, fmt.Errorf(`cannot specify both "--graph" and "--data-root" option`)
	}

	if opts.configFile != "" {
		c, err := config.MergeDaemonConfigurations(conf, flags, opts.configFile)
		if err != nil {
			if flags.Changed("config-file") || !os.IsNotExist(err) {
				return nil, fmt.Errorf("unable to configure the Docker daemon with file %s: %v\n", opts.configFile, err)
			}
		}
		// the merged configuration can be nil if the config file didn't exist.
		// leave the current configuration as it is if when that happens.
		if c != nil {
			conf = c
		}
	}

	if err := config.Validate(conf); err != nil {
		return nil, err
	}

	if conf.V2Only == false {
		logrus.Warnf(`The "disable-legacy-registry" option is deprecated and wil be removed in Docker v17.12. Interacting with legacy (v1) registries will no longer be supported in Docker v17.12"`)
	}

	if flags.Changed("graph") {
		logrus.Warnf(`The "-g / --graph" flag is deprecated. Please use "--data-root" instead`)
	}

	// Labels of the docker engine used to allow multiple values associated with the same key.
	// This is deprecated in 1.13, and, be removed after 3 release cycles.
	// The following will check the conflict of labels, and report a warning for deprecation.
	//
	// TODO: After 3 release cycles (17.12) an error will be returned, and labels will be
	// sanitized to consolidate duplicate key-value pairs (config.Labels = newLabels):
	//
	// newLabels, err := daemon.GetConflictFreeLabels(config.Labels)
	// if err != nil {
	//	return nil, err
	// }
	// config.Labels = newLabels
	//
	if _, err := config.GetConflictFreeLabels(conf.Labels); err != nil {
		logrus.Warnf("Engine labels with duplicate keys and conflicting values have been deprecated: %s", err)
	}

	// Regardless of whether the user sets it to true or false, if they
	// specify TLSVerify at all then we need to turn on TLS
	if conf.IsValueSet(FlagTLSVerify) {
		conf.TLS = true
	}

	// ensure that the log level is the one set after merging configurations
	setLogLevel(conf.LogLevel)

	return conf, nil
}

func initRouter(s *apiserver.Server, d *daemon.Daemon, c *cluster.Cluster) {
	decoder := runconfig.ContainerDecoder{}

	routers := []router.Router{
		// we need to add the checkpoint router before the container router or the DELETE gets masked
		checkpointrouter.NewRouter(d, decoder),
		container.NewRouter(d, decoder),
		image.NewRouter(d, decoder),
		systemrouter.NewRouter(d, c),
		volume.NewRouter(d),
		build.NewRouter(buildbackend.NewBackend(d, d, d.IDMappings()), d),
		swarmrouter.NewRouter(c),
		pluginrouter.NewRouter(d.PluginManager()),
		distributionrouter.NewRouter(d),
	}

	if d.NetworkControllerEnabled() {
		routers = append(routers, network.NewRouter(d, c))
	}

	if d.HasExperimental() {
		for _, r := range routers {
			for _, route := range r.Routes() {
				if experimental, ok := route.(router.ExperimentalRoute); ok {
					experimental.Enable()
				}
			}
		}
	}

	s.InitRouter(debug.IsEnabled(), routers...)
}

func (cli *DaemonCli) initMiddlewares(s *apiserver.Server, cfg *apiserver.Config, pluginStore *plugin.Store) error {
	v := cfg.Version

	exp := middleware.NewExperimentalMiddleware(cli.Config.Experimental)
	s.UseMiddleware(exp)

	vm := middleware.NewVersionMiddleware(v, api.DefaultVersion, api.MinVersion)
	s.UseMiddleware(vm)

	if cfg.EnableCors || cfg.CorsHeaders != "" {
		c := middleware.NewCORSMiddleware(cfg.CorsHeaders)
		s.UseMiddleware(c)
	}

	cli.authzMiddleware = authorization.NewMiddleware(cli.Config.AuthorizationPlugins, pluginStore)
	cli.Config.AuthzMiddleware = cli.authzMiddleware
	s.UseMiddleware(cli.authzMiddleware)
	return nil
}

// validates that the plugins requested with the --authorization-plugin flag are valid AuthzDriver
// plugins present on the host and available to the daemon
func validateAuthzPlugins(requestedPlugins []string, pg plugingetter.PluginGetter) error {
	for _, reqPlugin := range requestedPlugins {
		if _, err := pg.Get(reqPlugin, authorization.AuthZApiImplements, plugingetter.Lookup); err != nil {
			return err
		}
	}
	return nil
}