feat: implement app-json-is-valid plugin trigger

plugins/cron/cron.go

@@ -62,21 +62,32 @@ func (t TemplateCommand) CronCommand() string {
 	return fmt.Sprintf("dokku run --cron-id %s %s %s", t.ID, t.App, t.Command)
 }
 
+// FetchCronEntriesInput is the input for the FetchCronEntries function
+type FetchCronEntriesInput struct {
+	AppName string
+	AppJSON *appjson.AppJSON
+}
+
 // FetchCronEntries returns a list of cron commands for a given app
-func FetchCronEntries(appName string) ([]TemplateCommand, error) {
+func FetchCronEntries(input FetchCronEntriesInput) ([]TemplateCommand, error) {
+	appName := input.AppName
 	commands := []TemplateCommand{}
 	isMaintenance := reportComputedMaintenance(appName) == "true"
 
-	appJSON, err := appjson.GetAppJSON(appName)
-	if err != nil {
-		return commands, fmt.Errorf("Unable to fetch app.json for app %s: %s", appName, err.Error())
+	if input.AppJSON == nil {
+		appJSON, err := appjson.GetAppJSON(appName)
+		if err != nil {
+			return commands, fmt.Errorf("Unable to fetch app.json for app %s: %s", appName, err.Error())
+		}
+
+		input.AppJSON = &appJSON
 	}
 
-	if appJSON.Cron == nil {
+	if input.AppJSON.Cron == nil {
 		return commands, nil
 	}
 
-	for i, c := range appJSON.Cron {
+	for i, c := range input.AppJSON.Cron {
 		if c.Command == "" {
 			common.LogWarn(fmt.Sprintf("Missing cron command for app %s (index %d)", appName, i))
 			continue

plugins/cron/report.go

@@ -41,7 +41,7 @@ func reportMailto(_ string) string {
 }
 
 func reportTasks(appName string) string {
-	c, _ := FetchCronEntries(appName)
+	c, _ := FetchCronEntries(FetchCronEntriesInput{AppName: appName})
 	return strconv.Itoa(len(c))
 }
 

plugins/cron/subcommands.go

@@ -26,7 +26,7 @@ func CommandList(appName string, format string) error {
 		return fmt.Errorf("Invalid format specified, supported formats: json, stdout")
 	}
 
-	entries, err := FetchCronEntries(appName)
+	entries, err := FetchCronEntries(FetchCronEntriesInput{AppName: appName})
 	if err != nil {
 		return err
 	}
@@ -79,7 +79,7 @@ func CommandRun(appName string, cronID string, detached bool) error {
 		return err
 	}
 
-	entries, err := FetchCronEntries(appName)
+	entries, err := FetchCronEntries(FetchCronEntriesInput{AppName: appName})
 	if err != nil {
 		return err
 	}

plugins/cron/triggers.go

@@ -4,6 +4,7 @@ import (
 	"errors"
 	"fmt"
 
+	appjson "github.com/dokku/dokku/plugins/app-json"
 	"github.com/dokku/dokku/plugins/common"
 )
 
@@ -23,6 +24,25 @@ func TriggerCronGetProperty(appName string, key string) error {
 	return nil
 }
 
+// TriggerAppJSONIsValid validates the cron entries for a given app
+func TriggerAppJSONIsValid(appName string, appJSONPath string) error {
+	if !common.FileExists(appJSONPath) {
+		return nil
+	}
+
+	appJSON, err := appjson.ReadAppJSON(appJSONPath)
+	if err != nil {
+		return err
+	}
+
+	_, err = FetchCronEntries(FetchCronEntriesInput{AppName: appName, AppJSON: &appJSON})
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
 // TriggerInstall runs the install step for the cron plugin
 func TriggerInstall() error {
 	if err := common.PropertySetup("cron"); err != nil {