refactor: move app.json extraction up to core-post-extract

docs/appendices/0.30.0-migration-guide.md

@@ -1,5 +1,9 @@
 # 0.30.0 Migration Guide
 
+## Changes
+
+- The `app.json` file is now extracted from the source code instead of the built image. For deploys via `git:from-image`, the file is extracted from the built image.
+
 ## Removals
 
 - Support for [SPDY](https://en.wikipedia.org/wiki/SPDY) has been removed. No major browser supports it as of 2021. Custom `nginx.conf.sigil` templates referencing spdy-related variables will continue to build until the 1.0.0 release.

plugins/app-json/appjson.go

@@ -48,7 +48,7 @@ func GetAppjsonDirectory(appName string) string {
 	return common.GetAppDataDirectory("app-json", appName)
 }
 
-// GetAppjsonPath returns the path to a given app's extracted app.json file
+// GetAppjsonPath returns the path to a given app's extracted app.json file for use by other plugins
 func GetAppjsonPath(appName string) string {
-	return filepath.Join(GetAppjsonDirectory(appName), "app.json")
+	return getProcessSpecificAppJSONPath(appName)
 }

plugins/app-json/functions.go

@@ -8,6 +8,7 @@ import (
 	"fmt"
 	"io/ioutil"
 	"os"
+	"path/filepath"
 	"strconv"
 	"strings"
 
@@ -80,11 +81,11 @@ func constructScript(command string, shell string, isHerokuishImage bool, isCnbI
 }
 
 func getAppJSON(appName string) (AppJSON, error) {
-	if !common.FileExists(GetAppjsonPath(appName)) {
+	if !hasAppJSON(appName) {
 		return AppJSON{}, nil
 	}
 
-	b, err := ioutil.ReadFile(GetAppjsonPath(appName))
+	b, err := ioutil.ReadFile(getProcessSpecificAppJSONPath(appName))
 	if err != nil {
 		return AppJSON{}, fmt.Errorf("Cannot read app.json file: %v", err)
 	}
@@ -101,6 +102,21 @@ func getAppJSON(appName string) (AppJSON, error) {
 	return appJSON, nil
 }
 
+func getAppJSONPath(appName string) string {
+	directory := filepath.Join(common.MustGetEnv("DOKKU_LIB_ROOT"), "data", "app-json", appName)
+	return filepath.Join(directory, "app.json")
+}
+
+func getProcessSpecificAppJSONPath(appName string) string {
+	existingAppJSON := getAppJSONPath(appName)
+	processSpecificAppJSON := fmt.Sprintf("%s.%s", existingAppJSON, os.Getenv("DOKKU_PID"))
+	if common.FileExists(processSpecificAppJSON) {
+		return processSpecificAppJSON
+	}
+
+	return existingAppJSON
+}
+
 // getPhaseScript extracts app.json from app image and returns the appropriate json key/value
 func getPhaseScript(appName string, phase string) (string, error) {
 	appJSON, err := getAppJSON(appName)
@@ -155,6 +171,19 @@ func getDokkuAppShell(appName string) string {
 	return shell
 }
 
+func hasAppJSON(appName string) bool {
+	appJSONPath := getAppJSONPath(appName)
+	if common.FileExists(fmt.Sprintf("%s.%s.missing", appJSONPath, os.Getenv("DOKKU_PID"))) {
+		return false
+	}
+
+	if common.FileExists(fmt.Sprintf("%s.%s", appJSONPath, os.Getenv("DOKKU_PID"))) {
+		return true
+	}
+
+	return common.FileExists(appJSONPath)
+}
+
 func cleanupDeploymentContainer(appName string, containerID string, phase string) error {
 	if phase != "predeploy" {
 		os.Setenv("DOKKU_SKIP_IMAGE_RETIRE", "true")
@@ -453,30 +482,6 @@ func createdContainerID(appName string, dockerArgs []string, image string, comma
 	return containerID, err
 }
 
-func refreshAppJSON(appName string, image string) error {
-	baseDirectory := common.GetDataDirectory("app-json")
-	if !common.DirectoryExists(baseDirectory) {
-		return errors.New("Run 'dokku plugin:install' to ensure the correct directories exist")
-	}
-
-	directory := common.GetAppDataDirectory("app-json", appName)
-	if !common.DirectoryExists(directory) {
-		if err := os.MkdirAll(directory, 0755); err != nil {
-			return err
-		}
-	}
-
-	appjsonPath := GetAppjsonPath(appName)
-	if common.FileExists(appjsonPath) {
-		if err := os.Remove(appjsonPath); err != nil {
-			return errors.New("Unable to remove previous app.json file")
-		}
-	}
-
-	common.CopyFromImage(appName, image, reportComputedAppjsonpath(appName), appjsonPath)
-	return nil
-}
-
 func setScale(appName string, image string) error {
 	appJSON, err := getAppJSON(appName)
 	if err != nil {

plugins/app-json/triggers.go

@@ -3,8 +3,12 @@ package appjson
 import (
 	"fmt"
 	"os"
+	"path"
+	"path/filepath"
+	"strings"
 
 	"github.com/dokku/dokku/plugins/common"
+	"github.com/otiai10/copy"
 )
 
 // TriggerAppJSONProcessDeployParallelism returns the max number of processes to deploy in parallel
@@ -33,6 +37,83 @@ func TriggerAppJSONProcessDeployParallelism(appName string, processType string)
 	return nil
 }
 
+// TriggerCorePostDeploy sets a property to
+// allow the app to be restored on boot
+func TriggerCorePostDeploy(appName string) error {
+	existingAppJSON := getAppJSONPath(appName)
+	processSpecificAppJSON := fmt.Sprintf("%s.%s", existingAppJSON, os.Getenv("DOKKU_PID"))
+	if common.FileExists(processSpecificAppJSON) {
+		if err := os.Rename(processSpecificAppJSON, existingAppJSON); err != nil {
+			return err
+		}
+	} else if common.FileExists(fmt.Sprintf("%s.missing", processSpecificAppJSON)) {
+		if err := os.Remove(fmt.Sprintf("%s.missing", processSpecificAppJSON)); err != nil {
+			return err
+		}
+
+		if common.FileExists(existingAppJSON) {
+			if err := os.Remove(existingAppJSON); err != nil {
+				return err
+			}
+		}
+	}
+
+	return nil
+}
+
+// TriggerCorePostExtract ensures that the main app.json is the one specified by app-json-path
+func TriggerCorePostExtract(appName string, sourceWorkDir string) error {
+	appJSONPath := strings.Trim(reportComputedAppjsonpath(appName), "/")
+	if appJSONPath == "" {
+		appJSONPath = "app.json"
+	}
+
+	existingAppJSON := getAppJSONPath(appName)
+	files, err := filepath.Glob(fmt.Sprintf("%s.*", existingAppJSON))
+	if err != nil {
+		return err
+	}
+	for _, f := range files {
+		if err := os.Remove(f); err != nil {
+			return err
+		}
+	}
+
+	processSpecificAppJSON := fmt.Sprintf("%s.%s", existingAppJSON, os.Getenv("DOKKU_PID"))
+	b, _ := common.PlugnTriggerOutput("git-get-property", []string{appName, "source-image"}...)
+	appSourceImage := strings.TrimSpace(string(b[:]))
+
+	repoDefaultAppJSONPath := path.Join(sourceWorkDir, "app.json")
+	if appSourceImage == "" {
+		repoAppJSONPath := path.Join(sourceWorkDir, appJSONPath)
+		if !common.FileExists(repoAppJSONPath) {
+			if appJSONPath != "app.json" && common.FileExists(repoDefaultAppJSONPath) {
+				if err := os.Remove(repoDefaultAppJSONPath); err != nil {
+					return err
+				}
+			}
+			return common.TouchFile(fmt.Sprintf("%s.missing", processSpecificAppJSON))
+		}
+
+		if err := copy.Copy(repoAppJSONPath, processSpecificAppJSON); err != nil {
+			return fmt.Errorf("Unable to extract app.json: %v", err.Error())
+		}
+
+		if appJSONPath != "app.json" {
+			if err := copy.Copy(repoAppJSONPath, repoDefaultAppJSONPath); err != nil {
+				return fmt.Errorf("Unable to move app.json into place: %v", err.Error())
+			}
+		}
+	} else {
+		if err := common.CopyFromImage(appName, appSourceImage, appJSONPath, processSpecificAppJSON); err != nil {
+			return common.TouchFile(fmt.Sprintf("%s.missing", processSpecificAppJSON))
+		}
+	}
+
+	// TODO: add validation to app.json file by ensuring it can be deserialized
+	return nil
+}
+
 // TriggerInstall initializes app-json directory structures
 func TriggerInstall() error {
 	if err := common.PropertySetup("app-json"); err != nil {
@@ -104,10 +185,6 @@ func TriggerPostDeploy(appName string, imageTag string) error {
 // TriggerPreDeploy is a trigger to execute predeploy and release deployment tasks
 func TriggerPreDeploy(appName string, imageTag string) error {
 	image := common.GetAppImageName(appName, imageTag, "")
-	if err := refreshAppJSON(appName, image); err != nil {
-		return err
-	}
-
 	if err := executeScript(appName, image, imageTag, "predeploy"); err != nil {
 		return err
 	}