platform: modularize api/gui, add docs-tests-web foundation, and refresh root config

selective-vpn-api/app/dnscfg/systemd.go

@@ -0,0 +1,47 @@
+package dnscfg
+
+import "strings"
+
+type RunCommandFunc func(name string, args ...string) (stdout string, stderr string, exitCode int, err error)
+
+type CmdResult struct {
+	OK       bool
+	ExitCode int
+	Stdout   string
+	Stderr   string
+	Message  string
+}
+
+func UnitState(run RunCommandFunc, unit string) string {
+	if run == nil {
+		return "unknown"
+	}
+	stdout, _, _, _ := run("systemctl", "is-active", strings.TrimSpace(unit))
+	st := strings.TrimSpace(stdout)
+	if st == "" {
+		return "unknown"
+	}
+	return st
+}
+
+func RunUnitAction(run RunCommandFunc, unit, action string) CmdResult {
+	if run == nil {
+		return CmdResult{
+			OK:      false,
+			Message: "run command func is nil",
+		}
+	}
+	stdout, stderr, exitCode, err := run("systemctl", strings.TrimSpace(action), strings.TrimSpace(unit))
+	res := CmdResult{
+		OK:       err == nil && exitCode == 0,
+		ExitCode: exitCode,
+		Stdout:   stdout,
+		Stderr:   stderr,
+	}
+	if err != nil {
+		res.Message = err.Error()
+	} else {
+		res.Message = strings.TrimSpace(unit) + " " + strings.TrimSpace(action) + " done"
+	}
+	return res
+}