feat: add ability to suspend and resume a cron task by ID

This takes advantage of the properties system and allows users to suspend/resume the task at will.

plugins/common/properties.go

@@ -12,27 +12,27 @@ import (
 )
 
 // CommandPropertySet is a generic function that will set a property for a given plugin/app combination
-func CommandPropertySet(pluginName, appName, property, value string, properties map[string]string, globalProperties map[string]bool) {
+func CommandPropertySet(pluginName, appName, property, value string, validProperties map[string]string, validGlobalProperties map[string]bool) {
 	if appName != "--global" {
 		if err := VerifyAppName(appName); err != nil {
 			LogFailWithError(err)
 		}
 	}
-	if appName == "--global" && !globalProperties[property] {
+	if appName == "--global" && !validGlobalProperties[property] {
 		LogFail("Property cannot be specified globally")
 	}
 	if property == "" {
 		LogFail("No property specified")
 	}
 
-	for k := range globalProperties {
+	for k := range validGlobalProperties {
-		if _, ok := properties[k]; !ok {
+		if _, ok := validProperties[k]; !ok {
-			properties[k] = ""
+			validProperties[k] = ""
 		}
 	}
 
-	if _, ok := properties[property]; !ok {
+	if _, ok := validProperties[property]; !ok {
-		properties := reflect.ValueOf(properties).MapKeys()
+		properties := reflect.ValueOf(validProperties).MapKeys()
 		validPropertyList := make([]string, len(properties))
 		for i := 0; i < len(properties); i++ {
 			validPropertyList[i] = properties[i].String()

plugins/cron/Makefile

@@ -1,4 +1,4 @@
-SUBCOMMANDS = subcommands/list subcommands/report subcommands/run subcommands/set
+SUBCOMMANDS = subcommands/list subcommands/report cron/resume subcommands/run subcommands/set subcommands/suspend
 TRIGGERS = triggers/app-json-is-valid triggers/cron-get-property triggers/install triggers/post-app-clone-setup triggers/post-app-rename-setup triggers/post-delete triggers/scheduler-stop
 BUILD = commands subcommands triggers
 PLUGIN_NAME = cron

plugins/cron/cron.go

@@ -2,6 +2,7 @@ package cron
 
 import (
 	"fmt"
+	"strconv"
 	"strings"
 
 	appjson "github.com/dokku/dokku/plugins/app-json"
@@ -27,6 +28,8 @@ var (
 	}
 )
 
+const MaintenancePropertyPrefix = "maintenance."
+
 // CronTask is a struct that represents a cron task
 type CronTask struct {
 	// ID is a unique identifier for the cron task
@@ -102,6 +105,11 @@ func FetchCronTasks(input FetchCronTasksInput) ([]CronTask, error) {
 		return tasks, nil
 	}
 
+	properties, err := common.PropertyGetAllByPrefix("cron", appName, MaintenancePropertyPrefix)
+	if err != nil {
+		return tasks, fmt.Errorf("Error getting maintenance properties: %w", err)
+	}
+
 	for i, c := range input.AppJSON.Cron {
 		if c.Command == "" {
 			if input.WarnToFailure {
@@ -127,7 +135,19 @@ func FetchCronTasks(input FetchCronTasksInput) ([]CronTask, error) {
 			return tasks, fmt.Errorf("Invalid cron schedule for app %s (schedule %s): %s", appName, c.Schedule, err.Error())
 		}
 
-		maintenance := isAppCronInMaintenance || c.Maintenance
+		maintenance := c.Maintenance
+		if value, ok := properties[MaintenancePropertyPrefix+c.Schedule]; ok {
+			boolValue, err := strconv.ParseBool(value)
+			if err != nil {
+				return tasks, fmt.Errorf("Invalid maintenance property for app %s (schedule %s): %s", appName, c.Schedule, err.Error())
+			}
+
+			// only override the maintenance value if the property is set to true
+			if boolValue {
+				maintenance = boolValue
+			}
+		}
+
 		tasks = append(tasks, CronTask{
 			App:               appName,
 			Command:           c.Command,

plugins/cron/src/subcommands/subcommands.go

@@ -37,6 +37,12 @@ func main() {
 			appName := args.Arg(0)
 			err = cron.CommandReport(appName, *format, infoFlag)
 		}
+	case "resume":
+		args := flag.NewFlagSet("cron:resume", flag.ExitOnError)
+		args.Parse(os.Args[2:])
+		appName := args.Arg(0)
+		cronID := args.Arg(1)
+		err = cron.CommandResume(appName, cronID)
 	case "run":
 		args := flag.NewFlagSet("cron:run", flag.ExitOnError)
 		detached := args.Bool("detach", false, "--detach: run the container in a detached mode")
@@ -57,6 +63,12 @@ func main() {
 			value = args.Arg(1)
 		}
 		err = cron.CommandSet(appName, property, value)
+	case "suspend":
+		args := flag.NewFlagSet("cron:suspend", flag.ExitOnError)
+		args.Parse(os.Args[2:])
+		appName := args.Arg(0)
+		cronID := args.Arg(1)
+		err = cron.CommandSuspend(appName, cronID)
 	default:
 		err = fmt.Errorf("Invalid plugin subcommand call: %s", subcommand)
 	}

plugins/cron/subcommands.go

@@ -5,6 +5,7 @@ import (
 	"errors"
 	"fmt"
 	"os"
+	"strings"
 
 	"github.com/dokku/dokku/plugins/common"
 
@@ -43,7 +44,15 @@ func CommandList(appName string, format string) error {
 	if format == "stdout" {
 		output := []string{"ID | Schedule | Maintenance | Command"}
 		for _, task := range tasks {
-			output = append(output, fmt.Sprintf("%s | %s | %t | %s", task.ID, task.Schedule, task.Maintenance, task.Command))
+			maintenance := "false"
+			if task.Maintenance {
+				if task.TaskInMaintenance {
+					maintenance = "true (task)"
+				} else if task.AppInMaintenance {
+					maintenance = "true (app)"
+				}
+			}
+			output = append(output, fmt.Sprintf("%s | %s | %s | %s", task.ID, task.Schedule, maintenance, task.Command))
 		}
 
 		result := columnize.SimpleFormat(output)
@@ -82,6 +91,11 @@ func CommandReport(appName string, format string, infoFlag string) error {
 	return ReportSingleApp(appName, format, infoFlag)
 }
 
+// CommandResume resumes a cron task
+func CommandResume(appName string, cronID string) error {
+	return CommandSet(appName, fmt.Sprintf("%s%s", MaintenancePropertyPrefix, cronID), "")
+}
+
 // CommandRun executes a cron task on the fly
 func CommandRun(appName string, cronID string, detached bool) error {
 	if err := common.VerifyAppName(appName); err != nil {
@@ -138,7 +152,42 @@ func CommandSet(appName string, property string, value string) error {
 		return err
 	}
 
-	common.CommandPropertySet("cron", appName, property, value, DefaultProperties, GlobalProperties)
+	validProperties := DefaultProperties
+	globalProperties := GlobalProperties
+	if strings.HasPrefix(property, MaintenancePropertyPrefix) {
+		if appName == "--global" {
+			return fmt.Errorf("Task maintenance properties cannot be set globally")
+		}
+
+		maintenanceParts := strings.SplitN(property, ".", 2)
+		if len(maintenanceParts) != 3 {
+			return fmt.Errorf("Invalid task maintenance property, expected format: %s$ID: %s", MaintenancePropertyPrefix, property)
+		}
+
+		if maintenanceParts[1] == "" {
+			return fmt.Errorf("Invalid task maintenance property, missing ID")
+		}
+
+		tasks, err := FetchCronTasks(FetchCronTasksInput{AppName: appName})
+		if err != nil {
+			return err
+		}
+
+		maintenanceID := maintenanceParts[1]
+		for _, task := range tasks {
+			if task.ID == maintenanceID {
+				validProperties[property] = ""
+				globalProperties[property] = false
+				break
+			}
+		}
+
+		if _, ok := validProperties[property]; !ok {
+			return fmt.Errorf("Invalid task maintenance property, no matching task ID found: %s", property)
+		}
+	}
+
+	common.CommandPropertySet("cron", appName, property, value, validProperties, globalProperties)
 	scheduler := common.GetAppScheduler(appName)
 	_, err := common.CallPlugnTrigger(common.PlugnTriggerInput{
 		Trigger:     "scheduler-cron-write",
@@ -147,3 +196,8 @@ func CommandSet(appName string, property string, value string) error {
 	})
 	return err
 }
+
+// CommandSuspend suspends a cron task
+func CommandSuspend(appName string, cronID string) error {
+	return CommandSet(appName, fmt.Sprintf("%s%s", MaintenancePropertyPrefix, cronID), "true")
+}

plugins/scheduler-k3s/triggers.go

@@ -163,7 +163,7 @@ func TriggerSchedulerAppStatus(scheduler string, appName string) error {
 	return nil
 }
 
-// TriggerSchedulerCronWrite writes out cron entries for a given application
+// TriggerSchedulerCronWrite writes out cron tasks for a given application
 func TriggerSchedulerCronWrite(scheduler string, appName string) error {
 	if scheduler != "k3s" {
 		return nil
@@ -171,7 +171,7 @@ func TriggerSchedulerCronWrite(scheduler string, appName string) error {
 
 	cronTasks, err := cron.FetchCronTasks(cron.FetchCronTasksInput{AppName: appName})
 	if err != nil {
-		return fmt.Errorf("Error fetching cron entries: %w", err)
+		return fmt.Errorf("Error fetching cron tasks: %w", err)
 	}
 
 	ctx, cancel := context.WithCancel(context.Background())