Eventsignup Backend

© Juhani Vähä-Mäkilä (juhani@fmail.co.uk) and contributors 2024.

Licenced under EUPL-1.2 or later.

Backend microservice for event signup system. Includes Keycloak integration for authentication.

Used technologies

• Java 21
• Springboot 3.2.x
• Apache IO Commons
• Gradle
• Postgres 17
• JUnit 5 & Mockito
• Project lombok
• Keycloak for authentication
• Quartz scheduler
• OpenApi
• Spotless for code formatting
• Flyway

Development

• Expects Postgres at localhost:5432
• Server will be at localhost:8080
• OpenAPI definitions are available at http://localhost:8080/v1/api-docs.<yaml | json>
• OpenAPI swagger ui is available at http://localhost:8080/swagger-ui/index.html

To run the service:

$ ./gradlew bootRunDev

Setting up

1. Install OpenJDK21
   1. Windows
   2. Linux: Install from your distro's repo
   3. macOs
2. Install podman or docker. See container setup
   1. Run Postgres in a container: podman run -dt --pod new:postgres17 -e POSTGRES_PASSWORD=1234 -p 5432:5432 postgres:17.0 or docker run -d -p 5432:5432 --name postgres17 postgres:17.0
3. Import existing sources as a new project in your favorite IDE (e.g. IntelliJ IDEA)
4. Import Gradle project

Development guidelines

• All text which is visible to the end user (e.g. email) must use i18n translations (messages*.properties files).
• Main development happens in develop branch.
  • All features and bug fixes are done in their own branches (branched off from develop).
  • All Pull Requests should squash commits before merge so git history of develop (and ultimately master) remains clean and linear.
  • Delete source branch once PR is merged.
  • NEVER force-push to develop. This will break everyone else's work.
• Avoid commiting directly to develop. Only PRs will run CI pipelines.
• Only when a new version is to be released is develop merged into master.
• Use Semantic versioning for releases.
  • Use Git tags (created in master) for releases (builds containers) and the GitHub releases functionality.
• Use GitHub Issues for all features, bugs etc.
• Public interfaces need to have unit tests, and integration tests where appropriate.
• Use Project Lombok annotations for constructors, getters, setters etc.

Code quality

• All code, comments, documentation, names of classes and variables, log messages, etc. must be in English.
• Maximum recommended line length is 120 characters.
• Indentation must be made with 4 spaces, not tabs.
  • Continuation indent is 4.
• Line feeds must be UNIX-like (\n).
• All source files should be UTF-8, except .properties files which should be ISO-8859-1.
• Spotless is used to automatically format code (using palantirJavaFormat).
  • CI pipeline will fail if not properly formated.
• All your code should follow the Java Code Conventions regarding variable/method/class naming.
• Be DRY.
• Try to use test-driven-development.

Automatically format code with Spotless:

$ ./gradlew spotlessApply

Migrations with Flyway

Hibernate is able to update the database schema by itself pretty well though there are things it cannot/won't do e.g. remove a column from a table. For these instances we use Flyway to migrate the database schema.

How to run with containers only

If you just need the service up and running e.g. for front-end development or prod deployment here's how to do it.

Running locally

Note: Never use these commands in production!

1. Install Podman or docker
   1. Podman
      1. Windows
      2. Linux: install from your distro's repo
      3. macOs
   2. Docker Desktop: Windows, Linux, MacOs
2. Run Mongodb
   1. docker run -d -p 5432:5432 --name postgresql17 postgres:17.0 or
   2. podman run -dt --pod new:eventsignup -p 8080:8080 -e POSTGRES_PASSWORD=1234 -p 5432:5432 postgres:17.0
3. Authenticate to GHCR
4. Download .env-dev file from this repo
5. (Only for podman) podman run -d --pod=eventsignup --env-file=path/to/.env-dev ghcr.io/asteriskiry/eventsignup_backend:latest
   1. Note latest gives you the most recent CI pipeline built container which can be a dev snapshot. Use a version tag to get a specific version e.g. 1.0.0.

TODO complete docker instructions.

After initial run described above with podman the whole eventsignup system pod can be controlled like this podman pod start|stop|restart eventsignup.

Troubleshooting

If Podman gives an error try adding --network=slirp4netns:enable_ipv6=false to the command.

Running in production

Prerequisite: Postgres should be already running somewhere and the database exists.

1. Create a .env file somewhere with values for all the variables listed in environment variables table.
2. Run container
   1. podman run -d --pod=new:eventsignup -p 8080:8080 --env-file=path/to/.env ghcr.io/asteriskiry/eventsignup_backend:<tag> or
   2. docker run -d -p 8080:8080 --env-file=path/to/.env ghcr.io/asteriskiry/eventsignup_backend:<tag>

Note

• Substitute port numbers with the port you want to run the service with (must be the same as SERVER_PORT env variable).
• Substitute <tag> with a version tag e.g. 1.0.0.

Environment variables

For production these variables are needed.

Variable	Description	Example
SERVER_PORT	Which port the server is listening in	8080
SERVER_HOST	Hostname	localhost
SERVER_ENABLE_SSL	Whether to enable SSL support	true
DB_HOST	Hostname of postgresql server	localhost
DB_PORT	Which port postgresql is running	5432
DB_NAME	Name of the used database	databaseName
DB_USERNAME	User to connect to db with	user
DB_PASSWORD	Database user's password	password
SMTP_HOST	Hostname of SMTP server	localhost
SMTP_PORT	Port what SMTP server listens to	25
SMTP_USERNAME	SMTP servers user	user
SMTP_PASSWORD	SMTP user's password	password
DEFAULT_SENDER_EMAIL	Email address for outgoing email	noreply@example.com
DEFAULT_DAYS_TO_ARCHIVE_PAST_EVENTS	After how many days old events are automatically archived	180
DEFAULT_IMAGE_PATH	Directory where uploaded pictures are stored	/tmp
BASE_URL	Used to generate urls in emails	http://example.org
KEYCLOAK_ISSUER_URI	Url where Keycloak can be found	http://localhost:9090/realms/realmName
KEYCLOAK_CLIENT_NAME	Client name in Keycloak	example
KEYCLOAK_CLIENT_ID	Client id in Keycloak	example
KEYCLOAK_CLIENT_SECRET	Client secret in Keycloak	example
KEYCLOAK_URL	Url for Keycloak	http://localhost:9090
LOGOUT_URL	Url to redirect on logout	http://localhost:3000

Other info

• testFile.jpg is 'Imladris' by joewight (https://www.deviantart.com/joewight/art/Imladris-430740597). Distributed under CC by-nc-nd (http://creativecommons.org/licenses/by-nc-nd/3.0/).