OAuth twitter middleware for APItools

twitterAuthMiddleware.lua

return function (request, next_middleware)
  -- change to your own Twitter keys
  api_key = "MY_TWITTER_API_KEY"
  api_secret = "MY_TWITTER_API_SECRET"
  
  -- concatenate by ':'
  str = api_key .. ':' .. api_secret
  console.log(str)
  
  -- generate base64 string
  auth_header = "Basic ".. base64.encode(str)
  console.log(auth_header)
  
  -- headers to pass to /oauth2/ endpoint
  headers_val ={}
  headers_val["Authorization"]=auth_header
  headers_val["Content-Type"]="application/x-www-form-urlencoded;charset=UTF-8"
  
  -- call to get access_token
  local response = http.urlencoded.post('https://api.twitter.com/oauth2/token',{grant_type = "client_credentials"},{headers = { authorization=auth_header}})
  local resp = json.decode(response.body)
  
  request.headers.Authorization = "Bearer ".. resp.access_token
  console.log("access_token",resp.access_token)
  
  -- pass the access_token to auth call
  request.headers.Authorization = "Bearer ".. resp.access_token
  
  return next_middleware()
end