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.

docs/advanced-usage/deployment-tasks.md

@@ -24,6 +24,12 @@ Each "phase" has different expectations and limitations:
     - Example use-cases
         - Notifying slack that your app is deployed
         - Coordinating traffic routing with a central load balancer
+- `app.json`: `scripts.postdeploy`
+    - When to use: This should be used when you wish to run a command _once_, after the app is created and not on subsequent deploys to the app.
+    - Are changes committed to the image at this phase: No
+    - Example use-cases
+        - Setting up OAuth clients and DNS
+        - Loading seed/test data into the app’s test database
 - `Procfile`: `release`
     - When to use: This should be used in conjunction with external systems to signal the completion of your app image build.
     - Are changes committed to the image at this phase: No
@@ -44,6 +50,7 @@ Dokku provides limited support for the `app.json` manifest from Heroku (document
 
 - `scripts.dokku.predeploy`: This is run _after_ an app's docker image is built, but _before_ any containers are scheduled. Changes made to your image are committed at this phase.
 - `scripts.dokku.postdeploy`: This is run _after_ an app's containers are scheduled. Changes made to your image are *not* committed at this phase.
+- `scripts.postdeploy`: This is run _after_ an app's containers are scheduled. Changes made to your image are *not* committed at this phase.
 
 For buildpack-based deployments, the location of the `app.json` file should be at the root of your repository. Dockerfile-based app deploys should have the `app.json` in the configured `WORKDIR` directory; otherwise Dokku defaults to the buildpack app behavior of looking in `/app`.
 
@@ -57,7 +64,8 @@ The following is an example `app.json` file. Please note that only the `scripts.
     "dokku": {
       "predeploy": "touch /app/predeploy.test",
       "postdeploy": "curl https://some.external.api.service.com/deployment?state=success"
-    }
+    },
+    "postdeploy": "curl https://some.external.api.service.com/created?state=success"
   }
 }
 ```

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")
 }

tests/unit/app-json.bats

@@ -18,7 +18,7 @@ teardown() {
 }
 
 @test "(app-json) app.json scripts" {
-  run deploy_app nodejs-express
+  run deploy_app python
   echo "output: $output"
   echo "status: $status"
   assert_success
@@ -48,6 +48,16 @@ teardown() {
   assert_success
 }
 
+
+@test "(app-json) app.json scripts postdeploy" {
+  run deploy_app python dokku@dokku.me:$TEST_APP add_postdeploy_command
+  echo "output: $output"
+  echo "status: $status"
+  assert_success
+  assert_output_contains "touch /app/release.test" 2
+  assert_output_contains "python3 release.py" 2
+}
+
 @test "(app-json) app.json scripts missing" {
   run deploy_app nodejs-express-noappjson
   echo "output: $output"

tests/unit/test_helper.bash

@@ -514,6 +514,17 @@ add_release_command() {
   echo "release: touch /app/release.test" >>"$APP_REPO_DIR/Procfile"
 }
 
+
+add_postdeploy_command() {
+  local APP="$1"
+  local APP_REPO_DIR="$2"
+  [[ -z "$APP" ]] && local APP="$TEST_APP"
+  touch "$APP_REPO_DIR/app.json"
+  contents=$(jq '.scripts.postdeploy = "touch /app/heroku-postdeploy.test"' "$APP_REPO_DIR/app.json")
+  echo "${contents}" > "$APP_REPO_DIR/app.json"
+}
+
+
 add_requirements_txt() {
   local APP="$1"
   local APP_REPO_DIR="$2"