scala-hashtags-akka-streams

A personal example to learn Akka Streams basics and Docker

This includes:

• Basic example on bank accounts and web sockets taken from Paul Kinsky's intro to akka-streams
• Blocking Twitter consumption to show Graph DSL
• Streaming Twitter Publisher Actor pipeline on to a file
• Akka Http streaming endpoints that consume the files from both processes
• Tests - I couldn't get to use the akka-stream-testkit yet

Usage:

$ sbt run

will bring up a couple of main classes to run:

• you might want to choose the Server.scala to make both endpoints (tweets and websockets) available
• StreamingHashtags.scala to boot up a streaming processing of tweets on to a file on your /target directory
• BlockingHashtags.scala will output both to console and to a file named interesting-tweets.txt the most recent tweets that interested me according to the file on src/resources/interesting-hashtags.txt

$ sbt test

will output some tests results, they test most of the machinery behind these examples and common Sources, Flows and Sinks.

PS: Don't forget to fill in your twitter creds in order to access the Twitter API. This is on the Twitter.scala file.

API

• / will pop up the bank accounts backendish frontend, if you fill in a name and an amount and click on an action you should be able to see the bank's current state if you inspect what's going on on the browser's console
• /ws this endpoint is used by the bank accounts frontend to send the Withdraw or Deposit action through the websocket
• /tweets/blocking will bring up the contents of a local file in your target folder. You need to run BlockingHashtags.scala before.
• /tweets/streaming will bring up the contents of a local file in your target folder, product of running StreamingHashtags.scala

Docker

I used the awesome sbt-docker plugin to push this project and run it as a container anywhere, free of installing Scala or sbt. Just remember to configure where to push it on the imageName field on build.sbt

$ sbt dockerBuildAndPush

should do the trick for you.

Contributing

Feel obviously free to contribute to this project, open a pull request, or an issue and I'll be happy to address it. I've just started out with this awesome tool, constructive criticism is accepted.