scripts/lua/cors.lua

-- Copyright (c) 2016 IBM. All rights reserved.
--
--   Permission is hereby granted, free of charge, to any person obtaining a
--   copy of this software and associated documentation files (the "Software"),
--   to deal in the Software without restriction, including without limitation
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--   and/or sell copies of the Software, and to permit persons to whom the
--   Software is furnished to do so, subject to the following conditions:
--
--   The above copyright notice and this permission notice shall be included in
--   all copies or substantial portions of the Software.
--
--   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
--   IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
--   FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
--   AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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--   FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
--   DEALINGS IN THE SOFTWARE.

--- @module Cors
-- Used to set cors headers for preflight and simple requests

local _M = {}
local request = require "lib/request"

function _M.processCall(resourceConfig)
  if resourceConfig.cors ~= nil then
    ngx.var.cors_origins = resourceConfig.cors.origin
    ngx.var.cors_methods = resourceConfig.cors.methods
    if resourceConfig.cors.origin ~= 'false' and ngx.req.get_method() == "OPTIONS" then
      request.success(200)
    end
  end
end

function _M.replaceHeaders()
  if ngx.var.cors_origins ~= nil then
    if ngx.var.cors_origins == 'true' then
      ngx.header['Access-Control-Allow-Headers'] = ngx.req.get_headers()['Access-Control-Request-Headers']  
      ngx.header['Access-Control-Allow-Origin'] = '*'
      ngx.header['Access-Control-Allow-Methods'] = ngx.var.cors_methods
      if ngx.var.cors_methods == nil then
        ngx.header['Access-Control-Allow-Methods'] = 'GET, POST, PUT, DELETE, PATCH, HEAD, OPTIONS'
      end
    elseif ngx.var.cors_origins == 'false' then 
      ngx.header['Access-Control-Allow-Origin'] = nil
      ngx.header['Access-Control-Allow-Methods'] = nil
    else
      ngx.header['Access-Control-Allow-Origin'] = ngx.var.cors_origins
      ngx.header['Access-Control-Allow-Methods'] = ngx.var.cors_methods
      ngx.header['Access-Control-Allow-Headers'] = ngx.req.get_headers()['Access-Control-Request-Headers']  
      if ngx.var.cors_methods == nil then 
        ngx.header['Access-Control-Allow-Methods'] = 'GET, POST, PUT, DELETE, PATCH, HEAD, OPTIONS'
      end
    end
  end
end

return _M