/spray-akka-slick-postgres

Spray + Akka + Slick + Postgres (simple web service)

Primary LanguageScalaMIT LicenseMIT

Build status for master branch Build Status

Spray-Akka-Slick-PostgreSQL CRUD app

This app can be used to manage Tasks in a todo list

  • It is a basic REST micro-service.
  • It abstracts CRUD operations on a database (in this case PostgreSQL)
  • It can be run standalone using a web browser and CURL
  • or it can receive web service calls from a web frontend. This is a good idea as it separates the web frontend from being able to directly access the database.

Application stack

  • Akka actors for lightweight, event-driven concurrent entities
  • Spray HTTPX higher-level logic for working with HTTP messages, which is not specific to the server-side (spray-routing)
  • Spray Routing DSL for defining RESTful web services
  • Play JSON de/serialization
  • Slick Functional Relational Mapping for Scala
  • PostgreSQL database
  • ScalaTest testing framework
  • Travis CI build server. The file .travis.yml contains the settings for the build server. Currently PostgreSQL 9.1, 9.2 and 9.3 are supported.

Development prerequisites

  1. JDK 1.7.51 or 1.8 must be installed

  2. Install SBT. The [current documentation][install-sbt] suggests:

    Mac:

    • Install Homebrew
    • Get the latest updates brew update
    • Install using brew brew install sbt

  3. Install PostgreSQL (source):

    Mac:

    • Install using brew brew install PostgreSQL
    • Create/Upgrade a database initdb /usr/local/var/postgres -E utf8

  4. Optional - Install Lunchy. Lunchy is a tool that allows you to easily start and stop the Postgres service, but you may prefer using a PostgreSQL command.

  5. Start the database service:

    Lunchy:

    • lunchy start postgres

  6. Create a PostgreSQL database for the user (see stackoverflow answer)

Configuration

The file application.conf specifies the values for:

  1. Micro-service:
    • port (currently 3000)
    • url (currently localhost)
  2. Database settings:
    • port (currently 5432)
    • database name
    • username
    • default password

Usage

The following examples assume the application.conf file is configures the app to run on localhost on port 3000:

  1. GET

    As a REST web service, you can perform any of the GET actions through a web browser or through CURL:

    • Count number of entries in Tasks table:

    http://localhost:3000/api/v1/tasks/count

    • List all tasks in the Tasks table:

    http://localhost:3000/api/v1/tasks/

  2. POST

    Sending data to the micro-service can be performed by using CURL to a POST route:

    • Create the task "Buy milk" with assignee "Me":

    curl -i -H "Content-Type:application/json" -d '{"content":"Buy milk", "assignee":"Me"}' http://localhost:3000/api/v1/tasks/