Add support for system configuration (WIP)

scripts/lua/modules/sys_utils.lua

@@ -0,0 +1,150 @@
+--
+-- (C) 2013-20 - ntop.org
+--
+
+local sys_utils = {}
+
+-- If false, some commands and config files are not executed/created really
+-- This will be overwritten with the config value
+local REAL_EXEC = ntop.getPref("ntopng.prefs.nedge_real_exec") == "1"
+
+-- ################################################################
+
+local FileMock = {}
+FileMock.__index = FileMock
+
+function FileMock.open(fname, mode)
+  local obj = {}
+  setmetatable(obj, FileMock)
+  traceError(TRACE_NORMAL, TRACE_CONSOLE, "[File::" .. fname .. "]")
+  return obj
+end
+
+function FileMock:write(data)
+  local lines = split(data, "\n")
+
+  for _, line in pairs(lines) do
+    if not isEmptyString(line) then
+      traceError(TRACE_NORMAL, TRACE_CONSOLE, "\t"..line)
+    end
+  end
+
+  return true
+end
+
+function FileMock:close()
+  traceError(TRACE_NORMAL, TRACE_CONSOLE, "[File::END]")
+  return true
+end
+
+-- ################################################################
+
+function sys_utils.setRealExec(new_v)
+  REAL_EXEC = new_v
+  local v = ternary(REAL_EXEC, "1", "0")
+
+  if ntop.getPref("ntopng.prefs.nedge_real_exec") ~= v then
+    ntop.setPref("ntopng.prefs.nedge_real_exec", v)
+  end
+end
+
+-- ################################################################
+
+function sys_utils.openFile(fname, mode)
+  local cls
+
+  if REAL_EXEC then
+    cls = io
+  else
+    cls = FileMock
+  end
+
+  return cls.open(fname, mode)
+end
+
+-- ################################################################
+
+-- Execute a system command
+function sys_utils.execCmd(cmd)
+   if(REAL_EXEC) then
+    -- traceError(TRACE_NORMAL, TRACE_CONSOLE, "[execCmd] ".. cmd)
+    return(os.execute(cmd))
+   else
+    traceError(TRACE_NORMAL, TRACE_CONSOLE, "[execCmd] ".. cmd)
+    return 0
+   end
+end
+
+-- ################################################################
+
+-- execCmd with command output
+-- NOTE: no check for REAL_EXEC, the command will always be executed!
+function sys_utils.execShellCmd(c)
+   local f = assert(io.popen(c, 'r'))
+   local s = assert(f:read('*a'))
+   f:close()
+   return s
+end
+
+-- ################################################################
+
+local function _isServiceStatus(service_name, status)
+  local check_cmd = "systemctl is-"..status.." " .. service_name
+  local is_active = sys_utils.execShellCmd(check_cmd)
+
+  return ternary(string.match(is_active, "^"..status), true, false)
+end
+
+function sys_utils.isActiveService(service_name)
+   return _isServiceStatus(service_name, "active")
+end
+
+function sys_utils.isFailedService(service_name)
+   return _isServiceStatus(service_name, "failed")
+end
+
+function sys_utils.isActiveFailedService(service_name)
+  local check_cmd = "systemctl is-active " .. service_name
+  local is_active = sys_utils.execShellCmd(check_cmd)
+
+  return ternary(string.match(is_active, "inactive"), false, true)
+end
+
+-- ################################################################
+
+function sys_utils.enableService(service_name)
+  return sys_utils.execCmd("systemctl enable " .. service_name)
+end
+
+function sys_utils.disableService(service_name)
+  return sys_utils.execCmd("systemctl disable " .. service_name)
+end
+
+function sys_utils.restartService(service_name)
+  return sys_utils.execCmd("systemctl restart " .. service_name)
+end
+
+function sys_utils.stopService(service_name)
+  return sys_utils.execCmd("systemctl stop " .. service_name)
+end
+
+-- ################################################################
+
+function sys_utils.rebootSystem()
+  local do_reboot = ternary(REAL_EXEC, "reboot", nil)
+  ntop.shutdown(do_reboot)
+end
+
+function sys_utils.shutdownSystem()
+  local do_shutdown = ternary(REAL_EXEC, "poweroff", nil)
+  ntop.shutdown(do_shutdown)
+end
+
+function sys_utils.restartSelf()
+  local do_restart_self = ternary(REAL_EXEC, "restart_self", nil)
+  ntop.shutdown(do_restart_self)
+end
+
+-- ################################################################
+
+return sys_utils