feat: implement helper functions for dockeroptions

plugins/docker-options/dockeroptions.go

@@ -0,0 +1,102 @@
+package dockeroptions
+
+import (
+	"bufio"
+	"fmt"
+	"os"
+	"path/filepath"
+	"sort"
+	"strings"
+
+	"github.com/dokku/dokku/plugins/common"
+)
+
+// AddDockerOptionToPhases adds docker option to specified phases
+func AddDockerOptionToPhases(appName string, phases []string, option string) error {
+	for _, phase := range phases {
+		if err := touchPhaseFile(appName, phase); err != nil {
+			return err
+		}
+
+		options, err := GetDockerOptionsForPhase(appName, phase)
+		if err != nil {
+			return err
+		}
+
+		options = append(options, option)
+		sort.Strings(options)
+		if err = writeDockerOptionsForPhase(appName, phase, options); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// GetDockerOptionsForPhase returns the docker options for the specified phase
+func GetDockerOptionsForPhase(appName string, phase string) ([]string, error) {
+	options := []string{}
+
+	if err := touchPhaseFile(appName, phase); err != nil {
+		return options, err
+	}
+
+	phaseFilePath := getPhaseFilePath(appName, phase)
+	file, err := os.Open(phaseFilePath)
+	if err != nil {
+		return options, fmt.Errorf("Unable to open docker options phase file %s.%s: %s", appName, appName, err.Error())
+	}
+	defer file.Close()
+
+	scanner := bufio.NewScanner(file)
+	for scanner.Scan() {
+		options = append(options, strings.TrimSpace(scanner.Text()))
+	}
+
+	if err = scanner.Err(); err != nil {
+		return options, fmt.Errorf("Unable to read docker options phase file %s.%s: %s", appName, appName, err.Error())
+	}
+
+	return options, nil
+}
+
+func getPhaseFilePath(appName string, phase string) string {
+	return filepath.Join(common.MustGetEnv("DOKKU_ROOT"), appName, "DOCKER_OPTIONS_"+strings.ToUpper(phase))
+}
+
+func touchPhaseFile(appName string, phase string) error {
+	phaseFilePath := getPhaseFilePath(appName, phase)
+
+	_, err := os.Stat(phaseFilePath)
+	if !os.IsNotExist(err) {
+		return nil
+	}
+
+	file, err := os.Create(phaseFilePath)
+	if err != nil {
+		return fmt.Errorf("Unable to create docker options phase file %s.%s: %s", appName, phase, err.Error())
+	}
+	defer file.Close()
+
+	return nil
+}
+
+func writeDockerOptionsForPhase(appName string, phase string, options []string) error {
+	phaseFilePath := getPhaseFilePath(appName, phase)
+	file, err := os.OpenFile(phaseFilePath, os.O_RDWR|os.O_TRUNC, 0600)
+	if err != nil {
+		return err
+	}
+
+	w := bufio.NewWriter(file)
+	for _, option := range options {
+		fmt.Fprintln(w, option)
+	}
+	if err = w.Flush(); err != nil {
+		return fmt.Errorf("Unable to update docker options phase file %s.%s: %s", appName, phase, err.Error())
+	}
+
+	file.Chmod(0600)
+	common.SetPermissions(phaseFilePath, 0600)
+
+	return nil
+}