refactor: first pass at rewriting apps plugin in go

plugins/apps/functions.go

@@ -0,0 +1,163 @@
+package apps
+
+import (
+	"bytes"
+	"errors"
+	"fmt"
+	"os"
+	"strings"
+
+	"github.com/dokku/dokku/plugins/common"
+)
+
+// checks if an app exists
+func appExists(appName string) error {
+	if err := common.VerifyAppName(appName); err != nil {
+		return err
+	}
+
+	if !common.DirectoryExists(common.AppRoot(appName)) {
+		return fmt.Errorf("App %s does not exist", appName)
+	}
+
+	return nil
+}
+
+// checks if an app is locked
+func appIsLocked(appName string) bool {
+	lockfilePath := fmt.Sprintf("%v/.deploy.lock", common.AppRoot(appName))
+	_, err := os.Stat(lockfilePath)
+	return !os.IsNotExist(err)
+}
+
+// verifies app name and creates an app
+func createApp(appName string) error {
+	if err := common.IsValidAppName(appName); err != nil {
+		return err
+	}
+
+	if err := appExists(appName); err != nil {
+		return errors.New("Name is already taken")
+	}
+
+	common.LogInfo1Quiet(fmt.Sprintf("Creating %s...", appName))
+	os.MkdirAll(common.AppRoot(appName), 0755)
+
+	if err := common.PlugnTrigger("post-create", []string{appName}...); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+// destroys an app
+func destroyApp(appName string) error {
+	if err := common.VerifyAppName(appName); err != nil {
+		return err
+	}
+
+	imageTag, err := common.GetRunningImageTag(appName)
+	if err != nil {
+		return err
+	}
+
+	if os.Getenv("DOKKU_APPS_FORCE_DELETE") != "1" {
+		if err := common.AskForDestructiveConfirmation(appName, "app"); err != nil {
+			return err
+		}
+	}
+
+	common.LogInfo1(fmt.Sprintf("Destroying %s (including all add-ons)", appName))
+
+	if err := common.PlugnTrigger("pre-delete", []string{appName, imageTag}...); err != nil {
+		return err
+	}
+
+	scheduler := common.GetAppScheduler(appName)
+	removeContainers := "true"
+	if err := common.PlugnTrigger("scheduler-stop", []string{scheduler, appName, removeContainers}...); err != nil {
+		return err
+	}
+	if err := common.PlugnTrigger("scheduler-post-delete", []string{scheduler, appName, imageTag}...); err != nil {
+		return err
+	}
+	if err := common.PlugnTrigger("post-delete", []string{appName, imageTag}...); err != nil {
+		return err
+	}
+
+	forceCleanup := true
+	common.DockerCleanup(appName, forceCleanup)
+	return nil
+}
+
+func getAppName(args []string) (appName string, err error) {
+	if len(args) >= 1 {
+		appName = args[0]
+	} else {
+		err = errors.New("Please specify an app to run the command on")
+	}
+
+	return
+}
+
+func listImagesByAppLabel(appName string) ([]string, error) {
+	command := []string{
+		common.DockerBin(),
+		"image",
+		"list",
+		"--quiet",
+		"--filter",
+		fmt.Sprintf("label=com.dokku.app-name=%v", appName),
+	}
+
+	var stderr bytes.Buffer
+	listCmd := common.NewShellCmd(strings.Join(command, " "))
+	listCmd.ShowOutput = false
+	listCmd.Command.Stderr = &stderr
+	b, err := listCmd.Output()
+
+	if err != nil {
+		return []string{}, errors.New(strings.TrimSpace(stderr.String()))
+	}
+
+	output := strings.Split(strings.TrimSpace(string(b[:])), "\n")
+	return output, nil
+}
+
+func listImagesByImageRepo(imageRepo string) ([]string, error) {
+	command := []string{
+		common.DockerBin(),
+		"image",
+		"list",
+		"--quiet",
+		imageRepo,
+	}
+
+	var stderr bytes.Buffer
+	listCmd := common.NewShellCmd(strings.Join(command, " "))
+	listCmd.ShowOutput = false
+	listCmd.Command.Stderr = &stderr
+	b, err := listCmd.Output()
+
+	if err != nil {
+		return []string{}, errors.New(strings.TrimSpace(stderr.String()))
+	}
+
+	output := strings.Split(strings.TrimSpace(string(b[:])), "\n")
+	return output, nil
+}
+
+// creates an app if allowed
+func maybeCreateApp(appName string) error {
+	if err := appExists(appName); err == nil {
+		return nil
+	}
+
+	disableAutocreate := os.Getenv("DOKKU_GLOBAL_DISABLE_AUTOCREATE")
+	if disableAutocreate == "true" {
+		common.LogWarn("App auto-creation disabled.")
+		return fmt.Errorf("Re-enable app auto-creation or create an app with 'dokku apps:create %s'", appName)
+	}
+
+	return createApp(appName)
+}