amazonka-dynamodbの使い方を調査. ローカルのDynamoDBに接続できるようになった。

amazonka-dynamodb.hs

{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE FlexibleContexts  #-}

module Lib where

import           Control.Lens
import           Data.Aeson
import           Data.Aeson.Lens
import           Data.HashMap.Strict as M
import           Data.Maybe
import           Data.Monoid
import           Data.Text
import           Data.UUID
import           Data.UUID.V4
import           Network.AWS
import           Network.AWS.DynamoDB
import           Network.AWS.DynamoDB.Types

runMain = do
    e <- env
    runPutItem e
    scanRes <- runScan e
    mapM_ (\item -> do
                      print "----------"
                      putStrLn $ unpack $ fromMaybe "**Nothing**" $ (toJSON item) ^? key "requestId" . key "S" . _String
                      putStrLn $ show $ fromMaybe M.empty $ (toJSON item) ^? key "payload" . key "M" . _Object
                      putStrLn $ unpack $ fromMaybe "**Nothing**" $ processItem item
          ) $ scanRes^.srsItems

processItem item = (toJSON item) ^? key "payload" . key "M" . key "parameters" . key "M" . key "conversation" . key "S" . _String

runScan :: Env -> IO ScanResponse
runScan e = run e $ scan "some-table"

runPutItem :: Env -> IO PutItemResponse
runPutItem e = do
    ri <- nextRandom
    let payload  = M.fromList [
                      ("parameters", attributeValue&avM .~ M.fromList[("conversation", attributeValue&avS .~ Just "会話内容です。")])
                  ]
        item     = M.fromList [
                       ("requestId", attributeValue&avS .~ (Just $ toText ri))
                     , ("timestamp", attributeValue&avS .~ Just "2017-12-07 00:00:00")
                     , ("meetingId", attributeValue&avS .~ Just "100")
                     , ("payload"  , attributeValue&avM .~ payload)
                   ]
    run e $ (putItem "some-table")&piItem .~ item


{-- FlexibleContexts for this function --}
run e = runResourceT . runAWS e . send

env :: IO Env
env = do
    e <- newEnv $ FromEnv "AWS_ACCESS_KEY" "AWS_SECRET_ACCESS_KEY" Nothing Nothing
    pure $ e&envRegion .~ Tokyo &envOverride .~ localOverride

localOverride :: Dual (Endo Service)
localOverride = Dual $ Endo localService

localService :: Service -> Service
localService svc = svc { _svcEndpoint = \_ -> localEndpoint }

localEndpoint :: Endpoint
localEndpoint = Endpoint {
                  _endpointHost = "localhost"
                , _endpointSecure = False
                , _endpointPort = 8000
                , _endpointScope = ""
                }