split system update execution helpers

internal/service/system_update_command.go

@@ -0,0 +1,95 @@
+package service
+
+import (
+	"bytes"
+	"context"
+	"errors"
+	"os"
+	"os/exec"
+	"runtime"
+	"strings"
+)
+
+func (s *SystemUpdateService) updateCommand(ctx context.Context, status SystemUpdateStatus) string {
+	custom := s.rawUpdateCommand(ctx)
+	if strings.TrimSpace(custom) != "" {
+		return renderSystemUpdateCommand(custom, status)
+	}
+	return renderSystemUpdateCommand(defaultSystemUpdateCommand(), status)
+}
+
+func (s *SystemUpdateService) rawUpdateCommand(ctx context.Context) string {
+	return s.setting(ctx, SystemUpdateCommandSettingKey, os.Getenv("MEDIASTATION_UPDATE_COMMAND"))
+}
+
+func defaultSystemUpdateCommand() string {
+	return "docker run --rm -v /var/run/docker.sock:/var/run/docker.sock {{watchtower_image}} --run-once --cleanup {{container}}"
+}
+
+func renderSystemUpdateCommand(template string, status SystemUpdateStatus) string {
+	replacements := map[string]string{
+		"{{image}}":            shellQuote(status.Image),
+		"{{watchtower_image}}": shellQuote(firstNonEmpty(status.WatchtowerImage, DefaultSystemUpdateWatchtowerImage)),
+		"{{container}}":        shellQuote(firstNonEmpty(status.ContainerName, status.ContainerID)),
+		"{{container_id}}":     shellQuote(status.ContainerID),
+		"{{container_name}}":   shellQuote(status.ContainerName),
+	}
+	out := template
+	for marker, value := range replacements {
+		out = strings.ReplaceAll(out, marker, value)
+	}
+	return strings.TrimSpace(out)
+}
+
+func runSystemUpdateCommand(ctx context.Context, name string, args ...string) (string, error) {
+	cmd := exec.CommandContext(ctx, name, args...)
+	var buf bytes.Buffer
+	cmd.Stdout = &buf
+	cmd.Stderr = &buf
+	err := cmd.Run()
+	return buf.String(), err
+}
+
+func runSystemUpdateShell(ctx context.Context, command string) (string, error) {
+	if strings.TrimSpace(command) == "" {
+		return "", errors.New("empty update command")
+	}
+	if runtime.GOOS == "windows" {
+		return runSystemUpdateCommand(ctx, "cmd", "/C", command)
+	}
+	return runSystemUpdateCommand(ctx, "/bin/sh", "-c", command)
+}
+
+func systemUpdateOutputDetails(output string) []string {
+	output = strings.TrimSpace(output)
+	if output == "" {
+		return nil
+	}
+	lines := strings.Split(output, "\n")
+	if len(lines) > 12 {
+		lines = lines[len(lines)-12:]
+	}
+	for i := range lines {
+		lines[i] = strings.TrimRight(lines[i], "\r")
+	}
+	return lines
+}
+
+func redactSystemUpdateCommand(command string) string {
+	command = strings.TrimSpace(command)
+	if len(command) > 500 {
+		return command[:500] + "..."
+	}
+	return command
+}
+
+func shellQuote(value string) string {
+	value = strings.TrimSpace(value)
+	if value == "" {
+		return "''"
+	}
+	if runtime.GOOS == "windows" {
+		return `"` + strings.ReplaceAll(value, `"`, `\"`) + `"`
+	}
+	return "'" + strings.ReplaceAll(value, "'", `'\''`) + "'"
+}