feat: restart to apply update, privileged helper, rollback

internal/domain/update/updateInstall.go

@@ -0,0 +1,138 @@
+package update
+
+import (
+	"errors"
+	"strconv"
+	"strings"
+)
+
+var (
+	ErrNeedsLinux      = errors.New("Browser updates need Linux with systemd.")
+	ErrNeedsSystemd    = errors.New("Browser updates need systemd, which this machine is not running.")
+	ErrNeedsRoot       = errors.New("Run this command as root, for example with sudo.")
+	ErrServiceNotFound = errors.New("Could not find the RenewCMS service. Pass --service, --binary and --data-dir.")
+	ErrDataDirNotFound = errors.New("Could not find the data directory. Pass --data-dir.")
+	ErrInvalidPort     = errors.New("The port must be a number between 1 and 65535.")
+)
+
+const (
+	OSLinux             = "linux"
+	pathUnitDescription = "Watch for a RenewCMS restart request"
+)
+
+type ServiceDescription struct {
+	Name            string
+	BinaryPath      string
+	DataDir         string
+	EnvironmentFile string
+}
+
+type InstallOptions struct {
+	Service string
+	Binary  string
+	DataDir string
+	Port    string
+}
+
+type MachineProbe interface {
+	OS() string
+	SystemdRunning() bool
+	IsRoot() bool
+}
+
+type ServiceLocator interface {
+	Locate(name string) (ServiceDescription, bool)
+	PortFromEnvironmentFile(path string) (string, bool)
+}
+
+type UnitWriter interface {
+	Write(name string, content string) error
+	Remove(name string) (bool, error)
+}
+
+type UnitManager interface {
+	DaemonReload() error
+	EnableNow(unit string) error
+	DisableNow(unit string) error
+}
+
+type HelperStatusWriter interface {
+	Write(dataDir string, status HelperStatus) error
+	Remove(dataDir string) (bool, error)
+}
+
+func CheckInstallEnvironment(probe MachineProbe) error {
+	if probe.OS() != OSLinux {
+		return ErrNeedsLinux
+	}
+	if !probe.SystemdRunning() {
+		return ErrNeedsSystemd
+	}
+	if !probe.IsRoot() {
+		return ErrNeedsRoot
+	}
+	return nil
+}
+
+func ValidatePort(port string) error {
+	number, err := strconv.Atoi(port)
+	if err != nil || number < 1 || number > 65535 {
+		return ErrInvalidPort
+	}
+	return nil
+}
+
+func RenderPathUnit(layout HelperLayout) string {
+	lines := []string{
+		"[Unit]",
+		"Description=" + pathUnitDescription,
+		"",
+		"[Path]",
+		"PathExists=" + layout.RestartRequestPath(),
+		"Unit=" + ServiceUnitName,
+		"",
+		"[Install]",
+		"WantedBy=multi-user.target",
+		"",
+	}
+	return strings.Join(lines, "\n")
+}
+
+func RenderServiceUnit(options InstallOptions) string {
+	command := []string{
+		quoteUnitArgument(options.Binary),
+		"apply-update",
+		"--service", quoteUnitArgument(options.Service),
+		"--binary", quoteUnitArgument(options.Binary),
+		"--data-dir", quoteUnitArgument(options.DataDir),
+		"--port", options.Port,
+	}
+	lines := []string{
+		"[Unit]",
+		"Description=RenewCMS update helper",
+		"",
+		"[Service]",
+		"Type=oneshot",
+		"User=root",
+		"ExecStart=" + strings.Join(command, " "),
+		"",
+	}
+	return strings.Join(lines, "\n")
+}
+
+var unitArgumentEscaper = strings.NewReplacer(
+	`\`, `\\`,
+	`"`, `\"`,
+	`%`, `%%`,
+	`$`, `$$`,
+	"\n", `\n`,
+	"\r", `\r`,
+	"\t", `\t`,
+)
+
+func quoteUnitArgument(value string) string {
+	if !strings.ContainsAny(value, " \t\r\n\"'\\%$;") {
+		return value
+	}
+	return `"` + unitArgumentEscaper.Replace(value) + `"`
+}