Kong自定义插件【request-keyword-param-check】

1、插件作用

校验请求参数间的关系，支持以下操作类型：
（1）mandatory，表示请求uri中是必须携带的参数
（2）contain，表示两个参数之间是否有包含关系，前者是否包含后者
（3）exist，表示所配置参数必须同时有值
（4）begin，表示请求参数值是否以某个指定值开头
（5）end，表示请求参数值是否以某个指定值结尾
（6）firm，表示请求参数是否为指定的值

2、核心代码

local function decideUriExists(uri_key,uri_value,uri_param_tab,uri_relation_tab)
  local exists = true

  local args = ngx.req.get_uri_args()
  local http_uri_key_value = args[uri_key]
  if (http_uri_key_value ~= nil)  and  (string.lower(uri_value) == string.lower(http_uri_key_value)) then
    -- Nothing to do
  else
     return exists
  end 
  
  for i = 1, #uri_param_tab do
    local local_uri_param = uri_param_tab[i]
    local local_uri_relation = uri_relation_tab[i]
    local sub_uri_param_tab = setmetatable(pl_stringx.split(local_uri_param, ";"), nil)
    -- according to this parameter to decide if condition true or false
    local skip_flag = false 
    -- process different logic operation according to relation
    -- relation=mandatory
    if ('mandatory' == local_uri_relation) then
      skip_flag = true
      for j = 1, #sub_uri_param_tab do
        local local_uri_key=sub_uri_param_tab[j]
        local http_uri_arg_value = args[local_uri_key]
        if (http_uri_arg_value == nil or http_uri_arg_value == "") then
          exists = false
          break
        end
      end
    end
    -- whether to skip the outer circle logic
    if (not exists) then
    break
    end
    -- relation=contain,only compare two uri key 
    if (not skip_flag and 'contain' == local_uri_relation) then
      skip_flag = true
      local parent_key_value = args[sub_uri_param_tab[1]]
      local child_key_value = args[sub_uri_param_tab[2]]
      local idx_end = nil
      if (parent_key_value == nil or parent_key_value == "" or child_key_value == nil or child_key_value == "") then
         exists = false
         break
      else
        _,idx_end = string.find(string.lower(parent_key_value),string.lower(child_key_value))
      end
      if (idx_end ~= nil  and idx_end >= 1) then
        -- Nothing to do
      else
        exists = false
        break
      end
    end
   -- relationship=exist,only compare two uri key
    if (not skip_flag and 'exist' == local_uri_relation) then
      skip_flag = true
      local parent_key_value = args[sub_uri_param_tab[1]]
      local child_key_value = args[sub_uri_param_tab[2]]
      if ((parent_key_value ~= nil and parent_key_value ~= "" and child_key_value ~= nil and child_key_value == "") or (parent_key_value ~= nil and parent_key_value == "" and child_key_value ~= nil and child_key_value ~="")) then
        exists = false
        break
      end
    end
   -- relationship=begin,only compare two uri key
   if (not skip_flag and 'begin' == local_uri_relation) then
      skip_flag = true
      local parent_key_value = args[sub_uri_param_tab[1]]
      local child_value = sub_uri_param_tab[2]
      local idx_begin = nil
      if (parent_key_value == nil or parent_key_value == "") then
         exists = false
         break
      else
        idx_begin,_ = string.find(string.lower(parent_key_value),string.lower(child_value))
      end
      if (idx_begin ~= nil  and idx_begin == 1) then
      else
        exists = false
        break
      end
   end
   -- relationship=end,only compare two uri key
   if (not skip_flag and 'end' == local_uri_relation) then
      skip_flag = true
      local parent_key_value = args[sub_uri_param_tab[1]]
      local child_value = sub_uri_param_tab[2]
      local idx_end = nil
      if (parent_key_value == nil or parent_key_value == "") then
         exists = false
         break
      else
        _,idx_end = string.find(string.lower(parent_key_value),string.lower(child_value))
      end
      if (idx_end ~= nil  and idx_end == string.len(parent_key_value)) then
      else
        exists = false
        break
      end
   end
   -- relationship=firm,only compare two uri key
   if (not skip_flag and 'firm' == local_uri_relation) then
      skip_flag = true
      local counter = 0
      for j = 1, #sub_uri_param_tab do
        local sub_key_and_value_tab = setmetatable(pl_stringx.split(sub_uri_param_tab[j], "="), nil)
        local http_uri_arg_value = args[sub_key_and_value_tab[1]]
        if (http_uri_arg_value ~= nil and http_uri_arg_value ~= "" and sub_key_and_value_tab[2] ~= nil and sub_key_and_value_tab[2] ~= "" and sub_key_and_value_tab[2] == http_uri_arg_value) then
        counter = counter + 1
        end
      end
     if (counter == 1) then
      exists = false
      break
     end
   end
   -- for end location

  end

  return exists
end

3、配置使用
（1）多个分组逻辑间通过英文逗号（,）隔开，同一分组参数间通过英文分号（;）隔开
（2）注意多个分组逻辑间可以使用相同的操作符；
（3）示例如下：
uri_relation_set=>mandatory,contain,exist,firm,begin,end
uri_key_group_set=>key_x;key_y;key_z,key_a;key_b,key_m;key_n,key_d=d1;key_e=e1;key_f=f1,key_w;part_value_w,key_o;part_value_o

【温馨提示】
如果您觉得满意，可以选择支持下，您的支持是我最大的动力：