feat(config): swap viper and cobra for config (#684)

cmd/root.go

@@ -1,9 +1,10 @@
 package cmd
 
 import (
+	"fmt"
+	"github.com/spf13/viper"
 	"os"
 	"os/signal"
-	"strconv"
 	"syscall"
 	"time"
 
@@ -21,17 +22,9 @@ import (
 )
 
 var (
-	client         container.Client
-	scheduleSpec   string
-	cleanup        bool
-	noRestart      bool
-	monitorOnly    bool
-	enableLabel    bool
-	notifier       *notifications.Notifier
-	timeout        time.Duration
-	lifecycleHooks bool
-	rollingRestart bool
-	scope          string
+	client   container.Client
+	notifier *notifications.Notifier
+	c        flags.WatchConfig
 )
 
 var rootCmd = &cobra.Command{
@@ -46,10 +39,11 @@ More information available at https://github.com/containrrr/watchtower/.
 }
 
 func init() {
-	flags.SetDefaults()
 	flags.RegisterDockerFlags(rootCmd)
 	flags.RegisterSystemFlags(rootCmd)
 	flags.RegisterNotificationFlags(rootCmd)
+	flags.SetEnvBindings()
+	flags.BindViperFlags(rootCmd)
 }
 
 // Execute the root func and exit in case of errors
@@ -60,10 +54,10 @@ func Execute() {
 }
 
 // PreRun is a lifecycle hook that runs before the command is executed.
-func PreRun(cmd *cobra.Command, args []string) {
-	f := cmd.PersistentFlags()
+func PreRun(cmd *cobra.Command, _ []string) {
 
-	if enabled, _ := f.GetBool("no-color"); enabled {
+	// First apply all the settings that affect the output
+	if viper.GetBool("no-color") {
 		log.SetFormatter(&log.TextFormatter{
 			DisableColors: true,
 		})
@@ -74,75 +68,55 @@ func PreRun(cmd *cobra.Command, args []string) {
 		})
 	}
 
-	if enabled, _ := f.GetBool("debug"); enabled {
+	if viper.GetBool("debug") {
 		log.SetLevel(log.DebugLevel)
 	}
-	if enabled, _ := f.GetBool("trace"); enabled {
+	if viper.GetBool("trace") {
 		log.SetLevel(log.TraceLevel)
 	}
 
-	pollingSet := f.Changed("interval")
-	schedule, _ := f.GetString("schedule")
-	cronLen := len(schedule)
+	interval := viper.GetInt("interval")
 
-	if pollingSet && cronLen > 0 {
-		log.Fatal("Only schedule or interval can be defined, not both.")
-	} else if cronLen > 0 {
-		scheduleSpec, _ = f.GetString("schedule")
-	} else {
-		interval, _ := f.GetInt("interval")
-		scheduleSpec = "@every " + strconv.Itoa(interval) + "s"
+	// If empty, set schedule using interval helper value
+	if viper.GetString("schedule") == "" {
+		viper.Set("schedule", fmt.Sprintf("@every %ds", interval))
+	} else if interval != flags.DefaultInterval {
+		log.Fatal("only schedule or interval can be defined, not both")
 	}
 
-	flags.GetSecretsFromFiles(cmd)
-	cleanup, noRestart, monitorOnly, timeout = flags.ReadFlags(cmd)
+	// Then load the rest of the settings
+	err := viper.Unmarshal(&c)
+	if err != nil {
+		log.Fatalf("unable to decode into struct, %v", err)
+	}
 
-	if timeout < 0 {
+	flags.GetSecretsFromFiles()
+
+	if c.Timeout <= 0 {
 		log.Fatal("Please specify a positive value for timeout value.")
 	}
 
-	enableLabel, _ = f.GetBool("label-enable")
-	lifecycleHooks, _ = f.GetBool("enable-lifecycle-hooks")
-	rollingRestart, _ = f.GetBool("rolling-restart")
-	scope, _ = f.GetString("scope")
-
-	log.Debug(scope)
+	log.Debugf("Using scope %v", c.Scope)
 
-	// configure environment vars for client
-	err := flags.EnvConfig(cmd)
-	if err != nil {
-		log.Fatal(err)
+	if err = flags.EnvConfig(); err != nil {
+		log.Fatalf("failed to setup environment variables: %v", err)
 	}
 
-	noPull, _ := f.GetBool("no-pull")
-	includeStopped, _ := f.GetBool("include-stopped")
-	includeRestarting, _ := f.GetBool("include-restarting")
-	reviveStopped, _ := f.GetBool("revive-stopped")
-	removeVolumes, _ := f.GetBool("remove-volumes")
-
-	if monitorOnly && noPull {
+	if c.MonitorOnly && c.NoPull {
 		log.Warn("Using `WATCHTOWER_NO_PULL` and `WATCHTOWER_MONITOR_ONLY` simultaneously might lead to no action being taken at all. If this is intentional, you may safely ignore this message.")
 	}
 
-	client = container.NewClient(
-		!noPull,
-		includeStopped,
-		reviveStopped,
-		removeVolumes,
-		includeRestarting,
-	)
+	client = container.NewClient(&c)
 
 	notifier = notifications.NewNotifier(cmd)
 }
 
 // Run is the main execution flow of the command
-func Run(c *cobra.Command, names []string) {
-	filter := filters.BuildFilter(names, enableLabel, scope)
-	runOnce, _ := c.PersistentFlags().GetBool("run-once")
-	httpAPI, _ := c.PersistentFlags().GetBool("http-api")
+func Run(_ *cobra.Command, names []string) {
+	filter := filters.BuildFilter(names, c.EnableLabel, c.Scope)
 
-	if runOnce {
-		if noStartupMessage, _ := c.PersistentFlags().GetBool("no-startup-message"); !noStartupMessage {
+	if c.RunOnce {
+		if !c.NoStartupMessage {
 			log.Info("Running a one time update.")
 		}
 		runUpdatesWithNotifications(filter)
@@ -151,14 +125,12 @@ func Run(c *cobra.Command, names []string) {
 		return
 	}
 
-	if err := actions.CheckForMultipleWatchtowerInstances(client, cleanup, scope); err != nil {
+	if err := actions.CheckForMultipleWatchtowerInstances(client, c.Cleanup, c.Scope); err != nil {
 		log.Fatal(err)
 	}
 
-	if httpAPI {
-		apiToken, _ := c.PersistentFlags().GetString("http-api-token")
-
-		if err := api.SetupHTTPUpdates(apiToken, func() { runUpdatesWithNotifications(filter) }); err != nil {
+	if c.HTTPAPI {
+		if err := api.SetupHTTPUpdates(c.HTTPAPIToken, func() { runUpdatesWithNotifications(filter) }); err != nil {
 			log.Fatal(err)
 			os.Exit(1)
 		}
@@ -166,20 +138,20 @@ func Run(c *cobra.Command, names []string) {
 		api.WaitForHTTPUpdates()
 	}
 
-	if err := runUpgradesOnSchedule(c, filter); err != nil {
+	if err := runUpgradesOnSchedule(filter); err != nil {
 		log.Error(err)
 	}
 
 	os.Exit(1)
 }
 
-func runUpgradesOnSchedule(c *cobra.Command, filter t.Filter) error {
+func runUpgradesOnSchedule(filter t.Filter) error {
 	tryLockSem := make(chan bool, 1)
 	tryLockSem <- true
 
-	cron := cron.New()
-	err := cron.AddFunc(
-		scheduleSpec,
+	runner := cron.New()
+	err := runner.AddFunc(
+		viper.GetString("schedule"),
 		func() {
 			select {
 			case v := <-tryLockSem:
@@ -189,7 +161,7 @@ func runUpgradesOnSchedule(c *cobra.Command, filter t.Filter) error {
 				log.Debug("Skipped another update already running.")
 			}
 
-			nextRuns := cron.Entries()
+			nextRuns := runner.Entries()
 			if len(nextRuns) > 0 {
 				log.Debug("Scheduled next run: " + nextRuns[0].Next.String())
 			}
@@ -199,11 +171,11 @@ func runUpgradesOnSchedule(c *cobra.Command, filter t.Filter) error {
 		return err
 	}
 
-	if noStartupMessage, _ := c.PersistentFlags().GetBool("no-startup-message"); !noStartupMessage {
-		log.Info("Starting Watchtower and scheduling first run: " + cron.Entries()[0].Schedule.Next(time.Now()).String())
+	if !viper.GetBool("no-startup-message") {
+		log.Info("Starting Watchtower and scheduling first run: " + runner.Entries()[0].Schedule.Next(time.Now()).String())
 	}
 
-	cron.Start()
+	runner.Start()
 
 	// Graceful shut-down on SIGINT/SIGTERM
 	interrupt := make(chan os.Signal, 1)
@@ -211,7 +183,7 @@ func runUpgradesOnSchedule(c *cobra.Command, filter t.Filter) error {
 	signal.Notify(interrupt, syscall.SIGTERM)
 
 	<-interrupt
-	cron.Stop()
+	runner.Stop()
 	log.Info("Waiting for running update to be finished...")
 	<-tryLockSem
 	return nil
@@ -221,12 +193,12 @@ func runUpdatesWithNotifications(filter t.Filter) {
 	notifier.StartNotification()
 	updateParams := t.UpdateParams{
 		Filter:         filter,
-		Cleanup:        cleanup,
-		NoRestart:      noRestart,
-		Timeout:        timeout,
-		MonitorOnly:    monitorOnly,
-		LifecycleHooks: lifecycleHooks,
-		RollingRestart: rollingRestart,
+		Cleanup:        c.Cleanup,
+		NoRestart:      c.NoRestart,
+		Timeout:        c.Timeout,
+		MonitorOnly:    c.MonitorOnly,
+		LifecycleHooks: c.LifecycleHooks,
+		RollingRestart: c.RollingRestart,
 	}
 	err := actions.Update(client, updateParams)
 	if err != nil {

internal/flags/config.go

@@ -0,0 +1,31 @@
+package flags
+
+import (
+	"time"
+)
+
+// WatchConfig is the global watchtower configuration created from flags and environment variables
+type WatchConfig struct {
+	Interval          int
+	Schedule          string
+	NoPull            bool `mapstructure:"no-pull"`
+	NoRestart         bool `mapstructure:"no-restart"`
+	NoStartupMessage  bool `mapstructure:"no-startup-message"`
+	Cleanup           bool
+	RemoveVolumes     bool `mapstructure:"remove-volumes"`
+	EnableLabel       bool `mapstructure:"label-enable"`
+	Debug             bool
+	Trace             bool
+	MonitorOnly       bool          `mapstructure:"monitor-only"`
+	RunOnce           bool          `mapstructure:"run-once"`
+	IncludeStopped    bool          `mapstructure:"include-stopped"`
+	IncludeRestarting bool          `mapstructure:"include-restarting"`
+	ReviveStopped     bool          `mapstructure:"revive-stopped"`
+	LifecycleHooks    bool          `mapstructure:"enable-lifecycle-hooks"`
+	RollingRestart    bool          `mapstructure:"rolling-restart"`
+	HTTPAPI           bool          `mapstructure:"http-api"`
+	HTTPAPIToken      string        `mapstructure:"http-api-token"`
+	Timeout           time.Duration `mapstructure:"stop-timeout"`
+	Scope             string
+	NoColor           bool `mapstructure:"no-color"`
+}

internal/flags/flags.go

@@ -8,7 +8,6 @@ import (
 
 	log "github.com/sirupsen/logrus"
 	"github.com/spf13/cobra"
-	"github.com/spf13/pflag"
 	"github.com/spf13/viper"
 )
 
@@ -16,12 +15,15 @@ import (
 // use watchtower
 const DockerAPIMinVersion string = "1.25"
 
+// DefaultInterval is the default time between the start of update checks
+const DefaultInterval = int(time.Hour * 24 / time.Second)
+
 // RegisterDockerFlags that are used directly by the docker api client
 func RegisterDockerFlags(rootCmd *cobra.Command) {
 	flags := rootCmd.PersistentFlags()
-	flags.StringP("host", "H", viper.GetString("DOCKER_HOST"), "daemon socket to connect to")
-	flags.BoolP("tlsverify", "v", viper.GetBool("DOCKER_TLS_VERIFY"), "use TLS and verify the remote")
-	flags.StringP("api-version", "a", viper.GetString("DOCKER_API_VERSION"), "api version to use by docker client")
+	flags.StringP("host", "H", "unix:///var/run/docker.sock", "daemon socket to connect to")
+	flags.BoolP("tlsverify", "v", false, "use TLS and verify the remote")
+	flags.StringP("api-version", "a", DockerAPIMinVersion, "api version to use by docker client")
 }
 
 // RegisterSystemFlags that are used by watchtower to modify the program flow
@@ -30,126 +32,126 @@ func RegisterSystemFlags(rootCmd *cobra.Command) {
 	flags.IntP(
 		"interval",
 		"i",
-		viper.GetInt("WATCHTOWER_POLL_INTERVAL"),
+		DefaultInterval,
 		"poll interval (in seconds)")
 
 	flags.StringP(
 		"schedule",
 		"s",
-		viper.GetString("WATCHTOWER_SCHEDULE"),
+		"",
 		"the cron expression which defines when to update")
 
 	flags.DurationP(
 		"stop-timeout",
 		"t",
-		viper.GetDuration("WATCHTOWER_TIMEOUT"),
+		time.Second*10,
 		"timeout before a container is forcefully stopped")
 
 	flags.BoolP(
 		"no-pull",
 		"",
-		viper.GetBool("WATCHTOWER_NO_PULL"),
+		false,
 		"do not pull any new images")
 
 	flags.BoolP(
 		"no-restart",
 		"",
-		viper.GetBool("WATCHTOWER_NO_RESTART"),
+		false,
 		"do not restart any containers")
 
 	flags.BoolP(
 		"no-startup-message",
 		"",
-		viper.GetBool("WATCHTOWER_NO_STARTUP_MESSAGE"),
+		false,
 		"Prevents watchtower from sending a startup message")
 
 	flags.BoolP(
 		"cleanup",
 		"c",
-		viper.GetBool("WATCHTOWER_CLEANUP"),
+		false,
 		"remove previously used images after updating")
 
 	flags.BoolP(
 		"remove-volumes",
 		"",
-		viper.GetBool("WATCHTOWER_REMOVE_VOLUMES"),
+		false,
 		"remove attached volumes before updating")
 
 	flags.BoolP(
 		"label-enable",
 		"e",
-		viper.GetBool("WATCHTOWER_LABEL_ENABLE"),
+		false,
 		"watch containers where the com.centurylinklabs.watchtower.enable label is true")
 
 	flags.BoolP(
 		"debug",
 		"d",
-		viper.GetBool("WATCHTOWER_DEBUG"),
+		false,
 		"enable debug mode with verbose logging")
 
 	flags.BoolP(
 		"trace",
 		"",
-		viper.GetBool("WATCHTOWER_TRACE"),
+		false,
 		"enable trace mode with very verbose logging - caution, exposes credentials")
 
 	flags.BoolP(
 		"monitor-only",
 		"m",
-		viper.GetBool("WATCHTOWER_MONITOR_ONLY"),
+		false,
 		"Will only monitor for new images, not update the containers")
 
 	flags.BoolP(
 		"run-once",
 		"R",
-		viper.GetBool("WATCHTOWER_RUN_ONCE"),
+		false,
 		"Run once now and exit")
 
 	flags.BoolP(
 		"include-stopped",
 		"S",
-		viper.GetBool("WATCHTOWER_INCLUDE_STOPPED"),
+		false,
 		"Will also include created and exited containers")
 
 	flags.BoolP(
 		"revive-stopped",
 		"",
-		viper.GetBool("WATCHTOWER_REVIVE_STOPPED"),
+		false,
 		"Will also start stopped containers that were updated, if include-stopped is active")
 
 	flags.BoolP(
 		"enable-lifecycle-hooks",
 		"",
-		viper.GetBool("WATCHTOWER_LIFECYCLE_HOOKS"),
+		false,
 		"Enable the execution of commands triggered by pre- and post-update lifecycle hooks")
 
 	flags.BoolP(
 		"rolling-restart",
 		"",
-		viper.GetBool("WATCHTOWER_ROLLING_RESTART"),
+		false,
 		"Restart containers one at a time")
 
 	flags.BoolP(
 		"http-api",
 		"",
-		viper.GetBool("WATCHTOWER_HTTP_API"),
+		false,
 		"Runs Watchtower in HTTP API mode, so that image updates must to be triggered by a request")
 
 	flags.StringP(
 		"http-api-token",
 		"",
-		viper.GetString("WATCHTOWER_HTTP_API_TOKEN"),
+		"",
 		"Sets an authentication token to HTTP API requests.")
 	// https://no-color.org/
 	flags.BoolP(
 		"no-color",
 		"",
-		viper.IsSet("NO_COLOR"),
+		false,
 		"Disable ANSI color escape codes in log output")
 	flags.StringP(
 		"scope",
 		"",
-		viper.GetString("WATCHTOWER_SCOPE"),
+		"",
 		"Defines a monitoring scope for the Watchtower instance.")
 }
 
@@ -160,178 +162,177 @@ func RegisterNotificationFlags(rootCmd *cobra.Command) {
 	flags.StringSliceP(
 		"notifications",
 		"n",
-		viper.GetStringSlice("WATCHTOWER_NOTIFICATIONS"),
+		[]string{},
 		" notification types to send (valid: email, slack, msteams, gotify, shoutrrr)")
 
 	flags.StringP(
 		"notifications-level",
 		"",
-		viper.GetString("WATCHTOWER_NOTIFICATIONS_LEVEL"),
+		"info",
 		"The log level used for sending notifications. Possible values: panic, fatal, error, warn, info or debug")
 
 	flags.StringP(
 		"notification-email-from",
 		"",
-		viper.GetString("WATCHTOWER_NOTIFICATION_EMAIL_FROM"),
+		"",
 		"Address to send notification emails from")
 
 	flags.StringP(
 		"notification-email-to",
 		"",
-		viper.GetString("WATCHTOWER_NOTIFICATION_EMAIL_TO"),
+		"",
 		"Address to send notification emails to")
 
 	flags.IntP(
 		"notification-email-delay",
 		"",
-		viper.GetInt("WATCHTOWER_NOTIFICATION_EMAIL_DELAY"),
+		0,
 		"Delay before sending notifications, expressed in seconds")
 
 	flags.StringP(
 		"notification-email-server",
 		"",
-		viper.GetString("WATCHTOWER_NOTIFICATION_EMAIL_SERVER"),
+		"",
 		"SMTP server to send notification emails through")
 
 	flags.IntP(
 		"notification-email-server-port",
 		"",
-		viper.GetInt("WATCHTOWER_NOTIFICATION_EMAIL_SERVER_PORT"),
+		25,
 		"SMTP server port to send notification emails through")
 
 	flags.BoolP(
 		"notification-email-server-tls-skip-verify",
 		"",
-		viper.GetBool("WATCHTOWER_NOTIFICATION_EMAIL_SERVER_TLS_SKIP_VERIFY"),
+		false,
 		`Controls whether watchtower verifies the SMTP server's certificate chain and host name.
 Should only be used for testing.`)
 
 	flags.StringP(
 		"notification-email-server-user",
 		"",
-		viper.GetString("WATCHTOWER_NOTIFICATION_EMAIL_SERVER_USER"),
+		"",
 		"SMTP server user for sending notifications")
 
 	flags.StringP(
 		"notification-email-server-password",
 		"",
-		viper.GetString("WATCHTOWER_NOTIFICATION_EMAIL_SERVER_PASSWORD"),
+		"",
 		"SMTP server password for sending notifications")
 
 	flags.StringP(
 		"notification-email-subjecttag",
 		"",
-		viper.GetString("WATCHTOWER_NOTIFICATION_EMAIL_SUBJECTTAG"),
+		"",
 		"Subject prefix tag for notifications via mail")
 
 	flags.StringP(
 		"notification-slack-hook-url",
 		"",
-		viper.GetString("WATCHTOWER_NOTIFICATION_SLACK_HOOK_URL"),
+		"",
 		"The Slack Hook URL to send notifications to")
 
 	flags.StringP(
 		"notification-slack-identifier",
 		"",
-		viper.GetString("WATCHTOWER_NOTIFICATION_SLACK_IDENTIFIER"),
+		"watchtower",
 		"A string which will be used to identify the messages coming from this watchtower instance")
 
 	flags.StringP(
 		"notification-slack-channel",
 		"",
-		viper.GetString("WATCHTOWER_NOTIFICATION_SLACK_CHANNEL"),
+		"",
 		"A string which overrides the webhook's default channel. Example: #my-custom-channel")
 
 	flags.StringP(
 		"notification-slack-icon-emoji",
 		"",
-		viper.GetString("WATCHTOWER_NOTIFICATION_SLACK_ICON_EMOJI"),
+		"",
 		"An emoji code string to use in place of the default icon")
 
 	flags.StringP(
 		"notification-slack-icon-url",
 		"",
-		viper.GetString("WATCHTOWER_NOTIFICATION_SLACK_ICON_URL"),
+		"",
 		"An icon image URL string to use in place of the default icon")
 
 	flags.StringP(
 		"notification-msteams-hook",
 		"",
-		viper.GetString("WATCHTOWER_NOTIFICATION_MSTEAMS_HOOK_URL"),
+		"",
 		"The MSTeams WebHook URL to send notifications to")
 
 	flags.BoolP(
 		"notification-msteams-data",
 		"",
-		viper.GetBool("WATCHTOWER_NOTIFICATION_MSTEAMS_USE_LOG_DATA"),
+		false,
 		"The MSTeams notifier will try to extract log entry fields as MSTeams message facts")
 
 	flags.StringP(
 		"notification-gotify-url",
 		"",
-		viper.GetString("WATCHTOWER_NOTIFICATION_GOTIFY_URL"),
+		"",
 		"The Gotify URL to send notifications to")
 
 	flags.StringP(
 		"notification-gotify-token",
 		"",
-		viper.GetString("WATCHTOWER_NOTIFICATION_GOTIFY_TOKEN"),
+		"",
 		"The Gotify Application required to query the Gotify API")
 
 	flags.BoolP(
 		"notification-gotify-tls-skip-verify",
 		"",
-		viper.GetBool("WATCHTOWER_NOTIFICATION_GOTIFY_TLS_SKIP_VERIFY"),
+		false,
 		`Controls whether watchtower verifies the Gotify server's certificate chain and host name.
 Should only be used for testing.`)
 
 	flags.StringP(
 		"notification-template",
 		"",
-		viper.GetString("WATCHTOWER_NOTIFICATION_TEMPLATE"),
+		"",
 		"The shoutrrr text/template for the messages")
 
 	flags.StringArrayP(
 		"notification-url",
 		"",
-		viper.GetStringSlice("WATCHTOWER_NOTIFICATION_URL"),
+		[]string{},
 		"The shoutrrr URL to send notifications to")
 }
 
-// SetDefaults provides default values for environment variables
-func SetDefaults() {
-	day := (time.Hour * 24).Seconds()
+// SetEnvBindings binds environment variables to their corresponding config keys
+func SetEnvBindings() {
+	if err := viper.BindEnv("host", "DOCKER_HOST"); err != nil {
+		log.Fatalf("failed to bind env DOCKER_HOST: %v", err)
+	}
+	if err := viper.BindEnv("tlsverify", "DOCKER_TLS_VERIFY"); err != nil {
+		log.Fatalf("failed to bind env DOCKER_TLS_VERIFY: %v", err)
+	}
+	if err := viper.BindEnv("api-version", "DOCKER_API_VERSION"); err != nil {
+		log.Fatalf("failed to bind env DOCKER_API_VERSION: %v", err)
+	}
+	viper.SetEnvPrefix("WATCHTOWER")
+	viper.SetEnvKeyReplacer(strings.NewReplacer("-", "_"))
 	viper.AutomaticEnv()
-	viper.SetDefault("DOCKER_HOST", "unix:///var/run/docker.sock")
-	viper.SetDefault("DOCKER_API_VERSION", DockerAPIMinVersion)
-	viper.SetDefault("WATCHTOWER_POLL_INTERVAL", day)
-	viper.SetDefault("WATCHTOWER_TIMEOUT", time.Second*10)
-	viper.SetDefault("WATCHTOWER_NOTIFICATIONS", []string{})
-	viper.SetDefault("WATCHTOWER_NOTIFICATIONS_LEVEL", "info")
-	viper.SetDefault("WATCHTOWER_NOTIFICATION_EMAIL_SERVER_PORT", 25)
-	viper.SetDefault("WATCHTOWER_NOTIFICATION_EMAIL_SUBJECTTAG", "")
-	viper.SetDefault("WATCHTOWER_NOTIFICATION_SLACK_IDENTIFIER", "watchtower")
+}
+
+// BindViperFlags binds the cmd PFlags to the viper configuration
+func BindViperFlags(cmd *cobra.Command) {
+	if err := viper.BindPFlags(cmd.PersistentFlags()); err != nil {
+		log.Fatalf("failed to bind flags: %v", err)
+	}
 }
 
 // EnvConfig translates the command-line options into environment variables
 // that will initialize the api client
-func EnvConfig(cmd *cobra.Command) error {
+func EnvConfig() error {
 	var err error
-	var host string
 	var tls bool
 	var version string
 
-	flags := cmd.PersistentFlags()
-
-	if host, err = flags.GetString("host"); err != nil {
-		return err
-	}
-	if tls, err = flags.GetBool("tlsverify"); err != nil {
-		return err
-	}
-	if version, err = flags.GetString("api-version"); err != nil {
-		return err
-	}
+	host := viper.GetString("host")
+	tls = viper.GetBool("tlsverify")
+	version = viper.GetString("api-version")
 	if err = setEnvOptStr("DOCKER_HOST", host); err != nil {
 		return err
 	}
@@ -344,32 +345,6 @@ func EnvConfig(cmd *cobra.Command) error {
 	return nil
 }
 
-// ReadFlags reads common flags used in the main program flow of watchtower
-func ReadFlags(cmd *cobra.Command) (bool, bool, bool, time.Duration) {
-	flags := cmd.PersistentFlags()
-
-	var err error
-	var cleanup bool
-	var noRestart bool
-	var monitorOnly bool
-	var timeout time.Duration
-
-	if cleanup, err = flags.GetBool("cleanup"); err != nil {
-		log.Fatal(err)
-	}
-	if noRestart, err = flags.GetBool("no-restart"); err != nil {
-		log.Fatal(err)
-	}
-	if monitorOnly, err = flags.GetBool("monitor-only"); err != nil {
-		log.Fatal(err)
-	}
-	if timeout, err = flags.GetDuration("stop-timeout"); err != nil {
-		log.Fatal(err)
-	}
-
-	return cleanup, noRestart, monitorOnly, timeout
-}
-
 func setEnvOptStr(env string, opt string) error {
 	if opt == "" || opt == os.Getenv(env) {
 		return nil
@@ -390,9 +365,7 @@ func setEnvOptBool(env string, opt bool) error {
 
 // GetSecretsFromFiles checks if passwords/tokens/webhooks have been passed as a file instead of plaintext.
 // If so, the value of the flag will be replaced with the contents of the file.
-func GetSecretsFromFiles(rootCmd *cobra.Command) {
-	flags := rootCmd.PersistentFlags()
-
+func GetSecretsFromFiles() {
 	secrets := []string{
 		"notification-email-server-password",
 		"notification-slack-hook-url",
@@ -400,25 +373,19 @@ func GetSecretsFromFiles(rootCmd *cobra.Command) {
 		"notification-gotify-token",
 	}
 	for _, secret := range secrets {
-		getSecretFromFile(flags, secret)
+		getSecretFromFile(secret)
 	}
 }
 
 // getSecretFromFile will check if the flag contains a reference to a file; if it does, replaces the value of the flag with the contents of the file.
-func getSecretFromFile(flags *pflag.FlagSet, secret string) {
-	value, err := flags.GetString(secret)
-	if err != nil {
-		log.Error(err)
-	}
+func getSecretFromFile(secret string) {
+	value := viper.GetString(secret)
 	if value != "" && isFile(value) {
 		file, err := ioutil.ReadFile(value)
 		if err != nil {
 			log.Fatal(err)
 		}
-		err = flags.Set(secret, strings.TrimSpace(string(file)))
-		if err != nil {
-			log.Error(err)
-		}
+		viper.Set(secret, strings.TrimSpace(string(file)))
 	}
 }
 

internal/flags/flags_test.go

@@ -1,6 +1,7 @@
 package flags
 
 import (
+	"github.com/spf13/viper"
 	"io/ioutil"
 	"os"
 	"testing"
@@ -12,10 +13,11 @@ import (
 
 func TestEnvConfig_Defaults(t *testing.T) {
 	cmd := new(cobra.Command)
-	SetDefaults()
 	RegisterDockerFlags(cmd)
+	SetEnvBindings()
+	BindViperFlags(cmd)
 
-	err := EnvConfig(cmd)
+	err := EnvConfig()
 	require.NoError(t, err)
 
 	assert.Equal(t, "unix:///var/run/docker.sock", os.Getenv("DOCKER_HOST"))
@@ -26,13 +28,14 @@ func TestEnvConfig_Defaults(t *testing.T) {
 
 func TestEnvConfig_Custom(t *testing.T) {
 	cmd := new(cobra.Command)
-	SetDefaults()
 	RegisterDockerFlags(cmd)
+	SetEnvBindings()
+	BindViperFlags(cmd)
 
 	err := cmd.ParseFlags([]string{"--host", "some-custom-docker-host", "--tlsverify", "--api-version", "1.99"})
 	require.NoError(t, err)
 
-	err = EnvConfig(cmd)
+	err = EnvConfig()
 	require.NoError(t, err)
 
 	assert.Equal(t, "some-custom-docker-host", os.Getenv("DOCKER_HOST"))
@@ -71,11 +74,11 @@ func TestGetSecretsFromFilesWithFile(t *testing.T) {
 
 func testGetSecretsFromFiles(t *testing.T, flagName string, expected string) {
 	cmd := new(cobra.Command)
-	SetDefaults()
 	RegisterNotificationFlags(cmd)
-	GetSecretsFromFiles(cmd)
-	value, err := cmd.PersistentFlags().GetString(flagName)
-	require.NoError(t, err)
+	SetEnvBindings()
+	BindViperFlags(cmd)
+	GetSecretsFromFiles()
+	value := viper.GetString(flagName)
 
 	assert.Equal(t, expected, value)
 }

pkg/container/client.go

@@ -10,6 +10,7 @@ import (
 	"github.com/containrrr/watchtower/pkg/registry"
 	"github.com/containrrr/watchtower/pkg/registry/digest"
 
+	"github.com/containrrr/watchtower/internal/flags"
 	t "github.com/containrrr/watchtower/pkg/types"
 	"github.com/docker/docker/api/types"
 	"github.com/docker/docker/api/types/container"
@@ -41,7 +42,7 @@ type Client interface {
 //  * DOCKER_HOST			the docker-engine host to send api requests to
 //  * DOCKER_TLS_VERIFY		whether to verify tls certificates
 //  * DOCKER_API_VERSION	the minimum docker api version to work with
-func NewClient(pullImages bool, includeStopped bool, reviveStopped bool, removeVolumes bool, includeRestarting bool) Client {
+func NewClient(config *flags.WatchConfig) Client {
 	cli, err := sdkClient.NewClientWithOpts(sdkClient.FromEnv)
 
 	if err != nil {
@@ -50,11 +51,11 @@ func NewClient(pullImages bool, includeStopped bool, reviveStopped bool, removeV
 
 	return dockerClient{
 		api:               cli,
-		pullImages:        pullImages,
-		removeVolumes:     removeVolumes,
-		includeStopped:    includeStopped,
-		reviveStopped:     reviveStopped,
-		includeRestarting: includeRestarting,
+		pullImages:        !config.NoPull,
+		removeVolumes:     config.RemoveVolumes,
+		includeStopped:    config.IncludeStopped,
+		reviveStopped:     config.ReviveStopped,
+		includeRestarting: config.IncludeRestarting,
 	}
 }
 

pkg/notifications/email.go

@@ -4,6 +4,7 @@ import (
 	"encoding/base64"
 	"fmt"
 	"github.com/spf13/cobra"
+	"github.com/spf13/viper"
 	"net/smtp"
 	"os"
 	"strings"
@@ -33,18 +34,17 @@ type emailTypeNotifier struct {
 	delay                              time.Duration
 }
 
-func newEmailNotifier(c *cobra.Command, acceptedLogLevels []log.Level) t.Notifier {
-	flags := c.PersistentFlags()
+func newEmailNotifier(_ *cobra.Command, acceptedLogLevels []log.Level) t.Notifier {
 
-	from, _ := flags.GetString("notification-email-from")
-	to, _ := flags.GetString("notification-email-to")
-	server, _ := flags.GetString("notification-email-server")
-	user, _ := flags.GetString("notification-email-server-user")
-	password, _ := flags.GetString("notification-email-server-password")
-	port, _ := flags.GetInt("notification-email-server-port")
-	tlsSkipVerify, _ := flags.GetBool("notification-email-server-tls-skip-verify")
-	delay, _ := flags.GetInt("notification-email-delay")
-	subjecttag, _ := flags.GetString("notification-email-subjecttag")
+	from := viper.GetString("notification-email-from")
+	to := viper.GetString("notification-email-to")
+	server := viper.GetString("notification-email-server")
+	user := viper.GetString("notification-email-server-user")
+	password := viper.GetString("notification-email-server-password")
+	port := viper.GetInt("notification-email-server-port")
+	tlsSkipVerify := viper.GetBool("notification-email-server-tls-skip-verify")
+	delay := viper.GetInt("notification-email-delay")
+	subjecttag := viper.GetString("notification-email-subjecttag")
 
 	n := &emailTypeNotifier{
 		From:          from,
@@ -81,13 +81,13 @@ func (e *emailTypeNotifier) buildMessage(entries []*log.Entry) []byte {
 		// We don't use fields in watchtower, so don't bother sending them.
 	}
 
-	t := time.Now()
+	now := time.Now()
 
 	header := make(map[string]string)
 	header["From"] = e.From
 	header["To"] = e.To
 	header["Subject"] = emailSubject
-	header["Date"] = t.Format(time.RFC1123Z)
+	header["Date"] = now.Format(time.RFC1123Z)
 	header["MIME-Version"] = "1.0"
 	header["Content-Type"] = "text/plain; charset=\"utf-8\""
 	header["Content-Transfer-Encoding"] = "base64"

pkg/notifications/gotify.go

@@ -5,6 +5,7 @@ import (
 	"crypto/tls"
 	"encoding/json"
 	"fmt"
+	"github.com/spf13/viper"
 	"net/http"
 	"strings"
 
@@ -24,10 +25,10 @@ type gotifyTypeNotifier struct {
 	logLevels                []log.Level
 }
 
-func newGotifyNotifier(c *cobra.Command, acceptedLogLevels []log.Level) t.Notifier {
-	flags := c.PersistentFlags()
+func newGotifyNotifier(_ *cobra.Command, acceptedLogLevels []log.Level) t.Notifier {
+	flags := viper.Sub(".")
 
-	gotifyURL, _ := flags.GetString("notification-gotify-url")
+	gotifyURL := flags.GetString("notification-gotify-url")
 	if len(gotifyURL) < 1 {
 		log.Fatal("Required argument --notification-gotify-url(cli) or WATCHTOWER_NOTIFICATION_GOTIFY_URL(env) is empty.")
 	} else if !(strings.HasPrefix(gotifyURL, "http://") || strings.HasPrefix(gotifyURL, "https://")) {
@@ -36,12 +37,12 @@ func newGotifyNotifier(c *cobra.Command, acceptedLogLevels []log.Level) t.Notifi
 		log.Warn("Using an HTTP url for Gotify is insecure")
 	}
 
-	gotifyToken, _ := flags.GetString("notification-gotify-token")
+	gotifyToken := flags.GetString("notification-gotify-token")
 	if len(gotifyToken) < 1 {
 		log.Fatal("Required argument --notification-gotify-token(cli) or WATCHTOWER_NOTIFICATION_GOTIFY_TOKEN(env) is empty.")
 	}
 
-	gotifyInsecureSkipVerify, _ := flags.GetBool("notification-gotify-tls-skip-verify")
+	gotifyInsecureSkipVerify := flags.GetBool("notification-gotify-tls-skip-verify")
 
 	n := &gotifyTypeNotifier{
 		gotifyURL:                gotifyURL,

pkg/notifications/msteams.go

@@ -5,6 +5,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"github.com/spf13/cobra"
+	"github.com/spf13/viper"
 	"net/http"
 
 	t "github.com/containrrr/watchtower/pkg/types"
@@ -22,16 +23,14 @@ type msTeamsTypeNotifier struct {
 	data       bool
 }
 
-func newMsTeamsNotifier(cmd *cobra.Command, acceptedLogLevels []log.Level) t.Notifier {
+func newMsTeamsNotifier(_ *cobra.Command, acceptedLogLevels []log.Level) t.Notifier {
 
-	flags := cmd.PersistentFlags()
-
-	webHookURL, _ := flags.GetString("notification-msteams-hook")
+	webHookURL := viper.GetString("notification-msteams-hook")
 	if len(webHookURL) <= 0 {
 		log.Fatal("Required argument --notification-msteams-hook(cli) or WATCHTOWER_NOTIFICATION_MSTEAMS_HOOK_URL(env) is empty.")
 	}
 
-	withData, _ := flags.GetBool("notification-msteams-data")
+	withData := viper.GetBool("notification-msteams-data")
 	n := &msTeamsTypeNotifier{
 		levels:     acceptedLogLevels,
 		webHookURL: webHookURL,
@@ -85,19 +84,19 @@ func (n *msTeamsTypeNotifier) Fire(entry *log.Entry) error {
 
 		jsonBody, err := json.Marshal(webHookBody)
 		if err != nil {
-			fmt.Println("Failed to build JSON body for MSTeams notificattion: ", err)
+			fmt.Println("Failed to build JSON body for MSTeams notification: ", err)
 			return
 		}
 
-		resp, err := http.Post(n.webHookURL, "application/json", bytes.NewBuffer([]byte(jsonBody)))
+		resp, err := http.Post(n.webHookURL, "application/json", bytes.NewBuffer(jsonBody))
 		if err != nil {
-			fmt.Println("Failed to send MSTeams notificattion: ", err)
+			fmt.Println("Failed to send MSTeams notification: ", err)
 		}
 
 		defer resp.Body.Close()
 
 		if resp.StatusCode < 200 || resp.StatusCode > 299 {
-			fmt.Println("Failed to send MSTeams notificattion. HTTP RESPONSE STATUS: ", resp.StatusCode)
+			fmt.Println("Failed to send MSTeams notification. HTTP RESPONSE STATUS: ", resp.StatusCode)
 			if resp.Body != nil {
 				bodyBytes, err := ioutil.ReadAll(resp.Body)
 				if err == nil {

pkg/notifications/notifier.go

@@ -5,6 +5,7 @@ import (
 	"github.com/johntdyer/slackrus"
 	log "github.com/sirupsen/logrus"
 	"github.com/spf13/cobra"
+	"github.com/spf13/viper"
 )
 
 // Notifier can send log output as notification to admins, with optional batching.
@@ -16,9 +17,7 @@ type Notifier struct {
 func NewNotifier(c *cobra.Command) *Notifier {
 	n := &Notifier{}
 
-	f := c.PersistentFlags()
-
-	level, _ := f.GetString("notifications-level")
+	level := viper.GetString("notifications-level")
 	logLevel, err := log.ParseLevel(level)
 	if err != nil {
 		log.Fatalf("Notifications invalid log level: %s", err.Error())
@@ -27,7 +26,7 @@ func NewNotifier(c *cobra.Command) *Notifier {
 	acceptedLogLevels := slackrus.LevelThreshold(logLevel)
 
 	// Parse types and create notifiers.
-	types, err := f.GetStringSlice("notifications")
+	types := viper.GetStringSlice("notifications")
 	if err != nil {
 		log.WithField("could not read notifications argument", log.Fields{"Error": err}).Fatal()
 	}

pkg/notifications/shoutrrr.go

@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"fmt"
 	"github.com/containrrr/shoutrrr/pkg/types"
+	"github.com/spf13/viper"
 	"strings"
 	"text/template"
 
@@ -34,9 +35,8 @@ type shoutrrrTypeNotifier struct {
 }
 
 func newShoutrrrNotifier(c *cobra.Command, acceptedLogLevels []log.Level) t.Notifier {
-	flags := c.PersistentFlags()
 
-	urls, _ := flags.GetStringArray("notification-url")
+	urls := viper.GetStringSlice("notification-url")
 	r, err := shoutrrr.CreateSender(urls...)
 	if err != nil {
 		log.Fatalf("Failed to initialize Shoutrrr notifications: %s\n", err.Error())
@@ -126,12 +126,11 @@ func (e *shoutrrrTypeNotifier) Fire(entry *log.Entry) error {
 	return nil
 }
 
-func getShoutrrrTemplate(c *cobra.Command) *template.Template {
+func getShoutrrrTemplate(_ *cobra.Command) *template.Template {
 	var tpl *template.Template
+	var err error
 
-	flags := c.PersistentFlags()
-
-	tplString, err := flags.GetString("notification-template")
+	tplString := viper.GetString("notification-template")
 
 	funcs := template.FuncMap{
 		"ToUpper": strings.ToUpper,
@@ -141,7 +140,7 @@ func getShoutrrrTemplate(c *cobra.Command) *template.Template {
 
 	// If we succeed in getting a non-empty template configuration
 	// try to parse the template string.
-	if tplString != "" && err == nil {
+	if tplString != "" {
 		tpl, err = template.New("").Funcs(funcs).Parse(tplString)
 	}
 

pkg/notifications/shoutrrr_test.go

@@ -32,6 +32,7 @@ func TestShoutrrrDefaultTemplate(t *testing.T) {
 func TestShoutrrrTemplate(t *testing.T) {
 	cmd := new(cobra.Command)
 	flags.RegisterNotificationFlags(cmd)
+	flags.BindViperFlags(cmd)
 	err := cmd.ParseFlags([]string{"--notification-template={{range .}}{{.Level}}: {{.Message}}{{println}}{{end}}"})
 
 	require.NoError(t, err)
@@ -55,6 +56,7 @@ func TestShoutrrrTemplate(t *testing.T) {
 func TestShoutrrrStringFunctions(t *testing.T) {
 	cmd := new(cobra.Command)
 	flags.RegisterNotificationFlags(cmd)
+	flags.BindViperFlags(cmd)
 	err := cmd.ParseFlags([]string{"--notification-template={{range .}}{{.Level | printf \"%v\" | ToUpper }}: {{.Message | ToLower }} {{.Message | Title }}{{println}}{{end}}"})
 
 	require.NoError(t, err)
@@ -77,8 +79,8 @@ func TestShoutrrrStringFunctions(t *testing.T) {
 
 func TestShoutrrrInvalidTemplateUsesTemplate(t *testing.T) {
 	cmd := new(cobra.Command)
-
 	flags.RegisterNotificationFlags(cmd)
+	flags.BindViperFlags(cmd)
 	err := cmd.ParseFlags([]string{"--notification-template={{"})
 
 	require.NoError(t, err)
@@ -108,7 +110,7 @@ type blockingRouter struct {
 	sent   chan bool
 }
 
-func (b blockingRouter) Send(message string, params *types.Params) []error {
+func (b blockingRouter) Send(_ string, _ *types.Params) []error {
 	_ = <-b.unlock
 	b.sent <- true
 	return nil

pkg/notifications/slack.go

@@ -5,6 +5,7 @@ import (
 	"github.com/johntdyer/slackrus"
 	log "github.com/sirupsen/logrus"
 	"github.com/spf13/cobra"
+	"github.com/spf13/viper"
 )
 
 const (
@@ -15,14 +16,13 @@ type slackTypeNotifier struct {
 	slackrus.SlackrusHook
 }
 
-func newSlackNotifier(c *cobra.Command, acceptedLogLevels []log.Level) t.Notifier {
-	flags := c.PersistentFlags()
+func newSlackNotifier(_ *cobra.Command, acceptedLogLevels []log.Level) t.Notifier {
 
-	hookURL, _ := flags.GetString("notification-slack-hook-url")
-	userName, _ := flags.GetString("notification-slack-identifier")
-	channel, _ := flags.GetString("notification-slack-channel")
-	emoji, _ := flags.GetString("notification-slack-icon-emoji")
-	iconURL, _ := flags.GetString("notification-slack-icon-url")
+	hookURL := viper.GetString("notification-slack-hook-url")
+	userName := viper.GetString("notification-slack-identifier")
+	channel := viper.GetString("notification-slack-channel")
+	emoji := viper.GetString("notification-slack-icon-emoji")
+	iconURL := viper.GetString("notification-slack-icon-url")
 
 	n := &slackTypeNotifier{
 		SlackrusHook: slackrus.SlackrusHook{