syallop/snaplet-aws

A snaplet wrapping access to AWS via the amazonka package.

snaplet-aws

A boilerplate snaplet to conveniently allow amazonka aws functions to be lifted into snap web handlers.

Usage

1. Add the AWSEnv to your app's core state:

  import Snap.Snaplet.AWS

  data App = App
  {...
  ,_awsEnv :: Snaplet AWSEnv
  ,...
  }

2. Derive (or manually create) lenses:

  makeLenses ''App

3. Implement a HasEnv instance:

  instance HasEnv App where
    environment = awsEnv . environment

4. In your initialisation function, intialise like so, providing the desired credential discovery method:

  app :: SnapletInit App App
  app = makeSnaplet "app" "Your application" Nothing $ do
    ...
    awsSnaplet <- nestSnaplet "aws" awsEnv $ awsEnvInit Discover
    ...
    return $ App ... awsSnaplet ...

5. Ensure your Handler b v has a MonadCatch instance. E.G.

  -- Type-golf implementation...
  instance MonadCatch (Handler App App) where
    catch m f = join $ liftIO $ catch (return m) (\x -> return $ f x)

6. You should now be able to call liftAWS to lift aws functions into your handler. E.G.:

 -- Send a test email to a given address, returning whether sending was deemed successful by AWS.
 sendTestEmail :: Text -> Handler App App Bool
 sendTestEmail emailTo = do
  let emailBodyText = "<h1>Test</h1>"

      emailFrom     = "test@ourAddress.com"
      emailTo       = destination & dToAddresses .~ [emailTo]

      emailSubject  = content "Test email"
      emailBody     = body & bHTML .~ (Just $ content $ emailBodyText)
      emailMessage  = message emailSubject emailBody

      awsEmail      = sendEmail emailFrom emailTo emailMessage

  resp <- liftAWS $ within Ireland $ send awsEmail
  case resp&.sersResponseStatus of
    200 -> return True
    _   -> return False