feat: implement heroku's postdeploy deployment task

This occurs during the postdeploy on the first deploy of an app, mimicking heroku. It currently happens _after_ the `postdeploy` and `release` deploy tasks.

plugins/app-json/appjson.go

@@ -14,6 +14,7 @@ type AppJSON struct {
 			Predeploy  string `json:"predeploy"`
 			Postdeploy string `json:"postdeploy"`
 		} `json:"dokku"`
+		Postdeploy string `json:"postdeploy"`
 	} `json:"scripts"`
 }
 

plugins/app-json/functions.go

@@ -91,6 +91,10 @@ func getPhaseScript(appName string, phase string) (string, error) {
 		return "", fmt.Errorf("Cannot parse app.json: %v", err)
 	}
 
+	if phase == "heroku.postdeploy" {
+		return appJSON.Scripts.Postdeploy, nil
+	}
+
 	if phase == "predeploy" {
 		return appJSON.Scripts.Dokku.Predeploy, nil
 	}
@@ -143,7 +147,11 @@ func getDokkuAppShell(appName string) string {
 }
 
 func executeScript(appName string, image string, imageTag string, phase string) error {
-	common.LogInfo1(fmt.Sprintf("Checking for %s task", phase))
+	phaseName := phase
+	if phase == "heroku.postdeploy" {
+		phaseName = "first deploy postdeploy"
+	}
+	common.LogInfo1(fmt.Sprintf("Checking for %s task", phaseName))
 	command := ""
 	phaseSource := ""
 	if phase == "release" {
@@ -158,11 +166,11 @@ func executeScript(appName string, image string, imageTag string, phase string)
 	}
 
 	if command == "" {
-		common.LogVerbose(fmt.Sprintf("No %s task found, skipping", phase))
+		common.LogVerbose(fmt.Sprintf("No %s task found, skipping", phaseName))
 		return nil
 	}
 
-	common.LogInfo1(fmt.Sprintf("Executing %s task from %s: %s", phase, phaseSource, command))
+	common.LogInfo1(fmt.Sprintf("Executing %s task from %s: %s", phaseName, phaseSource, command))
 	isHerokuishImage := common.IsImageHerokuishBased(image, appName)
 	isCnbImage := common.IsImageCnbBased(image)
 	dockerfileEntrypoint := ""
@@ -241,15 +249,15 @@ func executeScript(appName string, image string, imageTag string, phase string)
 	}
 
 	if !waitForExecution(containerID) {
-		common.LogInfo2Quiet(fmt.Sprintf("Start of %s %s task (%s) output", appName, phase, containerID[0:9]))
+		common.LogInfo2Quiet(fmt.Sprintf("Start of %s %s task (%s) output", appName, phaseName, containerID[0:9]))
 		common.LogVerboseQuietContainerLogs(containerID)
-		common.LogInfo2Quiet(fmt.Sprintf("End of %s %s task (%s) output", appName, phase, containerID[0:9]))
-		common.LogFail(fmt.Sprintf("Execution of %s task failed: %s", phase, command))
+		common.LogInfo2Quiet(fmt.Sprintf("End of %s %s task (%s) output", appName, phaseName, containerID[0:9]))
+		common.LogFail(fmt.Sprintf("Execution of %s task failed: %s", phase, phaseName))
 	}
 
-	common.LogInfo2Quiet(fmt.Sprintf("Start of %s %s task (%s) output", appName, phase, containerID[0:9]))
+	common.LogInfo2Quiet(fmt.Sprintf("Start of %s %s task (%s) output", appName, phaseName, containerID[0:9]))
 	common.LogVerboseQuietContainerLogs(containerID)
-	common.LogInfo2Quiet(fmt.Sprintf("End of %s %s task (%s) output", appName, phase, containerID[0:9]))
+	common.LogInfo2Quiet(fmt.Sprintf("End of %s %s task (%s) output", appName, phaseName, containerID[0:9]))
 
 	if phase != "predeploy" {
 		return nil

plugins/app-json/triggers.go

@@ -1,6 +1,7 @@
 package appjson
 
 import (
+	"fmt"
 	"os"
 	"path/filepath"
 
@@ -9,16 +10,16 @@ import (
 
 // TriggerInstall initializes app restart policies
 func TriggerInstall() error {
+	if err := common.PropertySetup("common"); err != nil {
+		return fmt.Errorf("Unable to install the common plugin: %s", err.Error())
+	}
+
 	directory := filepath.Join(common.MustGetEnv("DOKKU_LIB_ROOT"), "data", "app-json")
 	if err := os.MkdirAll(directory, 0755); err != nil {
 		return err
 	}
 
-	if err := common.SetPermissions(directory, 0755); err != nil {
-		return err
-	}
-
-	return nil
+	return common.SetPermissions(directory, 0755)
 }
 
 // TriggerPostDelete destroys the app-json data for a given app container
@@ -41,10 +42,7 @@ func TriggerPostDeploy(appName string, imageTag string) error {
 		return err
 	}
 
-	if err := executeScript(appName, image, imageTag, "postdeploy"); err != nil {
-		return err
-	}
-	return nil
+	return executeScript(appName, image, imageTag, "postdeploy")
 }
 
 // TriggerPreDeploy is a trigger to execute predeploy and release deployment tasks
@@ -65,5 +63,19 @@ func TriggerPreDeploy(appName string, imageTag string) error {
 	if err := executeScript(appName, image, imageTag, "release"); err != nil {
 		return err
 	}
-	return nil
+
+	if common.PropertyGet("common", appName, "deployed") == "true" {
+		return nil
+	}
+
+	// Ensure that a failed postdeploy does not trigger twice
+	if common.PropertyGet("app-json", appName, "heroku.postdeploy") == "executed" {
+		return nil
+	}
+
+	if err := common.PropertyWrite("app-json", appName, "heroku.postdeploy", "executed"); err != nil {
+		return err
+	}
+
+	return executeScript(appName, image, imageTag, "heroku.postdeploy")
 }