preparations for soft deprecation of legacy notification args (#1377)

Co-authored-by: Simon Aronsson <simme@arcticbit.se>

cmd/notify-upgrade.go

@@ -0,0 +1,111 @@
+// Package cmd contains the watchtower (sub-)commands
+package cmd
+
+import (
+	"fmt"
+	"os"
+	"os/signal"
+	"strings"
+	"syscall"
+	"time"
+
+	"github.com/containrrr/watchtower/internal/flags"
+	"github.com/containrrr/watchtower/pkg/container"
+	"github.com/containrrr/watchtower/pkg/notifications"
+	"github.com/spf13/cobra"
+)
+
+var notifyUpgradeCommand = NewNotifyUpgradeCommand()
+
+// NewNotifyUpgradeCommand creates the notify upgrade command for watchtower
+func NewNotifyUpgradeCommand() *cobra.Command {
+	return &cobra.Command{
+		Use:   "notify-upgrade",
+		Short: "Upgrade legacy notification configuration to shoutrrr URLs",
+		Run:   runNotifyUpgrade,
+	}
+}
+
+func runNotifyUpgrade(cmd *cobra.Command, args []string) {
+	if err := runNotifyUpgradeE(cmd, args); err != nil {
+		logf("Notification upgrade failed: %v", err)
+	}
+}
+
+func runNotifyUpgradeE(cmd *cobra.Command, _ []string) error {
+	f := cmd.Flags()
+	flags.ProcessFlagAliases(f)
+
+	notifier = notifications.NewNotifier(cmd)
+	urls := notifier.GetURLs()
+
+	logf("Found notification configurations for: %v", strings.Join(notifier.GetNames(), ", "))
+
+	outFile, err := os.CreateTemp("/", "watchtower-notif-urls-*")
+	if err != nil {
+		return fmt.Errorf("failed to create output file: %v", err)
+	}
+	logf("Writing notification URLs to %v", outFile.Name())
+	logf("")
+
+	sb := strings.Builder{}
+	sb.WriteString("WATCHTOWER_NOTIFICATION_URL=")
+
+	for i, u := range urls {
+		if i != 0 {
+			sb.WriteRune(' ')
+		}
+		sb.WriteString(u)
+	}
+
+	_, err = fmt.Fprint(outFile, sb.String())
+	tryOrLog(err, "Failed to write to output file")
+
+	tryOrLog(outFile.Sync(), "Failed to sync output file")
+	tryOrLog(outFile.Close(), "Failed to close output file")
+
+	containerID := "<CONTAINER>"
+	cid, err := container.GetRunningContainerID()
+	tryOrLog(err, "Failed to get running container ID")
+	if cid != "" {
+		containerID = cid.ShortID()
+	}
+	logf("To get the environment file, use:")
+	logf("cp %v:%v ./watchtower-notifications.env", containerID, outFile.Name())
+	logf("")
+	logf("Note: This file will be removed in 5 minutes or when this container is stopped!")
+
+	signalChannel := make(chan os.Signal, 1)
+	time.AfterFunc(5*time.Minute, func() {
+		signalChannel <- syscall.SIGALRM
+	})
+
+	signal.Notify(signalChannel, os.Interrupt)
+	signal.Notify(signalChannel, syscall.SIGTERM)
+
+	switch <-signalChannel {
+	case syscall.SIGALRM:
+		logf("Timed out!")
+	case os.Interrupt, syscall.SIGTERM:
+		logf("Stopping...")
+	default:
+	}
+
+	if err := os.Remove(outFile.Name()); err != nil {
+		logf("Failed to remove file, it may still be present in the container image! Error: %v", err)
+	} else {
+		logf("Environment file has been removed.")
+	}
+
+	return nil
+}
+
+func tryOrLog(err error, message string) {
+	if err != nil {
+		logf("%v: %v\n", message, err)
+	}
+}
+
+func logf(format string, v ...interface{}) {
+	fmt.Fprintln(os.Stderr, fmt.Sprintf(format, v...))
+}

cmd/root.go

@@ -66,6 +66,7 @@ func init() {
 
 // Execute the root func and exit in case of errors
 func Execute() {
+	rootCmd.AddCommand(notifyUpgradeCommand)
 	if err := rootCmd.Execute(); err != nil {
 		log.Fatal(err)
 	}
@@ -139,6 +140,7 @@ func PreRun(cmd *cobra.Command, _ []string) {
 	})
 
 	notifier = notifications.NewNotifier(cmd)
+	notifier.AddLogHook()
 }
 
 // Run is the main execution flow of the command