Description

A simple CRUD REST API using:

• Play Framework for HTTP API
• doobie for DB access
• Flyway for DB migrations
• WIX Accord for validation
• Pureconfig for configuration
• sbt-play-swagger for swagger spec generation.

Prerequisites

• Install postgres
• Install Flyway https://flywaydb.org/download/community , extract and add the directory to system PATH variable
• Make sure postgres service is started.

Configure

Set DB config parameters in conf/application.conf and flyway.cfg files.

Init a database

Create a schema and a table with:

flyway -configFiles=flyway.cfg migrate

Flyway will execute all new scripts found in sql/ directory. There's only one script for now - sql/V1__init_db.sql.

DB migration approach

In contrast to Play Evolutions, DB migration process in this project is independent from the application. It doesn't require the application to be run in order to do a migration. This is convenient if multiple instances of the app may be started at the same time in cluster mode.

Run the app

Run the app with sbt run. The app will be available at http://localhost:9000/. Check /v1 API methods using swagger-ui. /v2 methods won't work correctly until v2 migration.

Migrate the table to the version 2

Copy sql2/V2__clients_add_age_column.sql file to sql/ directory and run:

flyway -configFiles=flyway.cfg migrate

This will add the nullable age column to the table. Right away, you'll be able to store and retrieve records with a value specified in this column using /v2 methods. /v1 methods will still work because age column is optional. Note: use integer value for the age field, since sbt-play-swagger plugin processes Short type incorrectly.

Failed validation response example

Status: Bad request
Payload:

{
  "errorId": "k47rm",
  "message": "Validation failed",
  "info": [
    "phone with value \"123\" has size 3, expected 5 or more"
  ]
}