expressions.lua

local _M = {}


local atc = require("kong.router.atc")
local gen_for_field = atc.gen_for_field


local OP_EQUAL    = "=="


local LOGICAL_AND = atc.LOGICAL_AND


local ngx_log = ngx.log
local ngx_ERR = ngx.ERR


-- map to normal protocol
local PROTOCOLS_OVERRIDE = {
  tls_passthrough = "tcp",
  grpc            = "http",
  grpcs           = "https",
}


local function get_exp_and_priority(route)
  local exp = route.expression
  if not exp then
    ngx_log(ngx_ERR, "expecting an expression route while it's not (probably a traditional route). ",
                     "Likely it's a misconfiguration. Please check the 'router_flavor' config in kong.conf")
    return
  end

  local gen = gen_for_field("net.protocol", OP_EQUAL, route.protocols,
                            function(_, p)
                              return PROTOCOLS_OVERRIDE[p] or p
                            end)
  if gen then
    exp = exp .. LOGICAL_AND .. gen
  end

  return exp, route.priority
end


function _M.new(routes, cache, cache_neg, old_router)
  return atc.new(routes, cache, cache_neg, old_router, get_exp_and_priority)
end


-- for unit-testing purposes only
_M._set_ngx = atc._set_ngx


return _M