feat: order/delay in service files, enable cmd, --all on unit commands

- install/uninstall/start/stop/enable take <name> or --all; *all kept as shortcuts
- add enable (enable at boot + start); startall no longer enables
- order/delay resolved by config.ResolveOrder and written into systemd,
  OpenRC and runit service files (After=/sleep), so they apply at boot
- install --all stops and disables units before removing their files
- update regenerates all installed, enabled units and removes disabled ones
- edit creates the config dir; docs and man page updated
- tests: fake Init for cmd, ResolveOrder, backend ordering output

openrc/openrc.go

@@ -10,6 +10,7 @@ import (
 	"os/exec"
 	"path/filepath"
 	"strings"
+	"time"
 
 	"github.com/warkanum/unitdore/config"
 	"github.com/warkanum/unitdore/service"
@@ -194,13 +195,28 @@ func (b Backend) Generate(u config.Unit, prefix, suffix string) (string, error)
 	if u.Runtime == "docker" {
 		w.WriteString("\tneed docker\n")
 	}
+	if len(u.After) > 0 {
+		names := make([]string, len(u.After))
+		for i, n := range u.After {
+			names[i] = service.BaseName(config.Unit{Name: n}, prefix, suffix)
+		}
+		fmt.Fprintf(&w, "\tafter %s\n", strings.Join(names, " "))
+	}
 	w.WriteString("}\n")
 
+	var pre []string
+	if spec.Type != service.TypeOneshot && user != nil {
+		pre = append(pre, fmt.Sprintf("checkpath -d -m 0700 -o %s %s",
+			service.ShellQuote(user.Name), service.ShellQuote(user.RuntimeDir)))
+	}
+	if secs := delaySeconds(u); secs > 0 {
+		pre = append(pre, fmt.Sprintf("sleep %d", secs))
+	}
+	if len(pre) > 0 {
+		fmt.Fprintf(&w, "\nstart_pre() {\n\t%s\n}\n", strings.Join(pre, "\n\t"))
+	}
+
 	if spec.Type != service.TypeOneshot {
-		if user != nil {
-			fmt.Fprintf(&w, "\nstart_pre() {\n\tcheckpath -d -m 0700 -o %s %s\n}\n",
-				service.ShellQuote(user.Name), service.ShellQuote(user.RuntimeDir))
-		}
 		if stop != "" {
 			fmt.Fprintf(&w, "\nstop_pre() {\n\t%s || true\n}\n", asUser(user, stop))
 		}
@@ -277,3 +293,8 @@ func dq(s string) string {
 	r := strings.NewReplacer(`\`, `\\`, `"`, `\"`, "$", `\$`, "`", "\\`")
 	return `"` + r.Replace(s) + `"`
 }
+
+// delaySeconds rounds the unit's start delay up to whole seconds.
+func delaySeconds(u config.Unit) int {
+	return int((u.StartDelay + time.Second - 1) / time.Second)
+}