package main // import "github.com/v2tec/watchtower" import ( "os" "os/signal" "syscall" "time" "strconv" "github.com/robfig/cron" log "github.com/sirupsen/logrus" "github.com/urfave/cli" "github.com/v2tec/watchtower/actions" "github.com/v2tec/watchtower/container" "github.com/v2tec/watchtower/notifications" ) // DockerAPIMinVersion is the version of the docker API, which is minimally required by // watchtower. Currently we require at least API 1.24 and therefore Docker 1.12 or later. const DockerAPIMinVersion string = "1.24" var version = "master" var commit = "unknown" var date = "unknown" var ( client container.Client scheduleSpec string cleanup bool noRestart bool notifier *notifications.Notifier ) func init() { log.SetLevel(log.InfoLevel) } func main() { app := cli.NewApp() app.Name = "watchtower" app.Version = version + " - " + commit + " - " + date app.Usage = "Automatically update running Docker containers" app.Before = before app.Action = start app.Flags = []cli.Flag{ cli.StringFlag{ Name: "host, H", Usage: "daemon socket to connect to", Value: "unix:///var/run/docker.sock", EnvVar: "DOCKER_HOST", }, cli.IntFlag{ Name: "interval, i", Usage: "poll interval (in seconds)", Value: 300, EnvVar: "WATCHTOWER_POLL_INTERVAL", }, cli.StringFlag{ Name: "schedule, s", Usage: "the cron expression which defines when to update", EnvVar: "WATCHTOWER_SCHEDULE", }, cli.BoolFlag{ Name: "no-pull", Usage: "do not pull new images", EnvVar: "WATCHTOWER_NO_PULL", }, cli.BoolFlag{ Name: "no-restart", Usage: "do not restart containers", EnvVar: "WATCHTOWER_NO_RESTART", }, cli.BoolFlag{ Name: "cleanup", Usage: "remove old images after updating", EnvVar: "WATCHTOWER_CLEANUP", }, cli.BoolFlag{ Name: "tlsverify", Usage: "use TLS and verify the remote", EnvVar: "DOCKER_TLS_VERIFY", }, cli.BoolFlag{ Name: "label-enable", Usage: "watch containers where the com.centurylinklabs.watchtower.enable label is true", EnvVar: "WATCHTOWER_LABEL_ENABLE", }, cli.BoolFlag{ Name: "debug", Usage: "enable debug mode with verbose logging", }, cli.StringSliceFlag{ Name: "notifications", Value: &cli.StringSlice{}, Usage: "notification types to send (valid: email, slack)", EnvVar: "WATCHTOWER_NOTIFICATIONS", }, cli.StringFlag{ Name: "notifications-level", Usage: "The log level used for sending notifications. Possible values: \"panic\", \"fatal\", \"error\", \"warn\", \"info\" or \"debug\"", EnvVar: "WATCHTOWER_NOTIFICATIONS_LEVEL", Value: "info", }, cli.StringFlag{ Name: "notification-email-from", Usage: "Address to send notification e-mails from", EnvVar: "WATCHTOWER_NOTIFICATION_EMAIL_FROM", }, cli.StringFlag{ Name: "notification-email-to", Usage: "Address to send notification e-mails to", EnvVar: "WATCHTOWER_NOTIFICATION_EMAIL_TO", }, cli.StringFlag{ Name: "notification-email-server", Usage: "SMTP server to send notification e-mails through", EnvVar: "WATCHTOWER_NOTIFICATION_EMAIL_SERVER", }, cli.IntFlag{ Name: "notification-email-server-port", Usage: "SMTP server port to send notification e-mails through", Value: 25, EnvVar: "WATCHTOWER_NOTIFICATION_EMAIL_SERVER_PORT", }, cli.BoolFlag{ Name: "notification-email-server-tls-skip-verify", Usage: "Controls whether watchtower verifies the SMTP server's certificate chain and host name. " + "If set, TLS accepts any certificate " + "presented by the server and any host name in that certificate. " + "In this mode, TLS is susceptible to man-in-the-middle attacks. " + "This should be used only for testing.", EnvVar: "WATCHTOWER_NOTIFICATION_EMAIL_SERVER_TLS_SKIP_VERIFY", }, cli.StringFlag{ Name: "notification-email-server-user", Usage: "SMTP server user for sending notifications", EnvVar: "WATCHTOWER_NOTIFICATION_EMAIL_SERVER_USER", }, cli.StringFlag{ Name: "notification-email-server-password", Usage: "SMTP server password for sending notifications", EnvVar: "WATCHTOWER_NOTIFICATION_EMAIL_SERVER_PASSWORD", }, cli.StringFlag{ Name: "notification-slack-hook-url", Usage: "The Slack Hook URL to send notifications to", EnvVar: "WATCHTOWER_NOTIFICATION_SLACK_HOOK_URL", }, cli.StringFlag{ Name: "notification-slack-identifier", Usage: "A string which will be used to identify the messages coming from this watchtower instance. Default if omitted is \"watchtower\"", EnvVar: "WATCHTOWER_NOTIFICATION_SLACK_IDENTIFIER", Value: "watchtower", }, } if err := app.Run(os.Args); err != nil { log.Fatal(err) } } func before(c *cli.Context) error { if c.GlobalBool("debug") { log.SetLevel(log.DebugLevel) } pollingSet := c.IsSet("interval") cronSet := c.IsSet("schedule") if pollingSet && cronSet { log.Fatal("Only schedule or interval can be defined, not both.") } else if cronSet { scheduleSpec = c.String("schedule") } else { scheduleSpec = "@every " + strconv.Itoa(c.Int("interval")) + "s" } cleanup = c.GlobalBool("cleanup") noRestart = c.GlobalBool("no-restart") // configure environment vars for client err := envConfig(c) if err != nil { return err } client = container.NewClient(!c.GlobalBool("no-pull"), c.GlobalBool("label-enable")) notifier = notifications.NewNotifier(c) return nil } func start(c *cli.Context) error { names := c.Args() if err := actions.CheckPrereqs(client, cleanup); err != nil { log.Fatal(err) } tryLockSem := make(chan bool, 1) tryLockSem <- true cron := cron.New() err := cron.AddFunc( scheduleSpec, func() { select { case v := <-tryLockSem: defer func() { tryLockSem <- v }() notifier.StartNotification() if err := actions.Update(client, names, cleanup, noRestart); err != nil { log.Println(err) } notifier.SendNotification() default: log.Debug("Skipped another update already running.") } nextRuns := cron.Entries() if len(nextRuns) > 0 { log.Debug("Scheduled next run: " + nextRuns[0].Next.String()) } }) if err != nil { return err } log.Info("First run: " + cron.Entries()[0].Schedule.Next(time.Now()).String()) cron.Start() // Graceful shut-down on SIGINT/SIGTERM interrupt := make(chan os.Signal, 1) signal.Notify(interrupt, os.Interrupt) signal.Notify(interrupt, syscall.SIGTERM) <-interrupt cron.Stop() log.Info("Waiting for running update to be finished...") <-tryLockSem os.Exit(1) return nil } func setEnvOptStr(env string, opt string) error { if opt != "" && opt != os.Getenv(env) { err := os.Setenv(env, opt) if err != nil { return err } } return nil } func setEnvOptBool(env string, opt bool) error { if opt == true { return setEnvOptStr(env, "1") } return nil } // envConfig translates the command-line options into environment variables // that will initialize the api client func envConfig(c *cli.Context) error { var err error err = setEnvOptStr("DOCKER_HOST", c.GlobalString("host")) err = setEnvOptBool("DOCKER_TLS_VERIFY", c.GlobalBool("tlsverify")) err = setEnvOptStr("DOCKER_API_VERSION", DockerAPIMinVersion) return err }