Support for containerized deployment and cloud service hosting

[teezip]

Support and documentation for:

• deployment as a Docker container (actions, hakunapi-simple-webapp bundled as a container, etc)
• hakunapi-simple-webapp published in a container register (GitHub, Docker or Azure)
• example app (https://github.com/nlsfi/hakunapi/tree/main/examples/finnish_addresses) also as a container with instructions
• example app container deployed to a cloud service (ie. Azure App Service) to host a demo service

Currently the finnish_addresses example is available online (https://beta-paikkatieto.maanmittauslaitos.fi/inspire-addresses/features/v1/) without access restriction, but not in a managed cloud service.

[tsallinen]

Some enhancements should be made to Hakunapi in order to enable PAAS or containerized deployment:

• Support configuring database connection settings as environment variables (as an alternative to db.properties)
• Optionally support Azure managed identity for database authentication (instead of username/password). See https://learn.microsoft.com/en-us/azure/postgresql/flexible-server/connect-java?tabs=passwordless
• Support environment variables as an alternative to any system properties ({context_path}.hakuna.config.path)
• Construct links dynamically from request headers (Host, X-Forwarded-*) instead of static configuration (servers.dev.url)

[jampukka]

If I understand the passwordless example correctly users should now be able to create their own version of hakunapi-simple-webapp-javax and include the

<dependency>
  <groupId>com.azure</groupId>
  <artifactId>azure-identity-extensions</artifactId>
  <version>1.0.0</version>
</dependency>

in the war project and configure their database connections with jdbcUrl instead of dataSourceClassName causing HikariCP to call DriverManager.getConnection(jdbcUrl, props) just like the example code does

Current example configuration:

dataSourceClassName=org.postgresql.ds.PGSimpleDataSource
dataSource.user=address_reader
dataSource.password=test
dataSource.databaseName=address_fin
dataSource.portNumber=5432
dataSource.serverName=localhost

How it could work:

jdbcUrl=jdbc:postgresql://${AZ_DATABASE_SERVER_NAME}.postgres.database.azure.com:5432/${AZ_DATABASE_NAME}?sslmode=require&authenticationPluginClassName=com.azure.identity.extensions.jdbc.postgresql.AzurePostgresqlAuthenticationPlugin
dataSource.user=address_reader

[jampukka]

Quick test, adding

<dependency>
  <groupId>com.azure</groupId>
  <artifactId>azure-identity-extensions</artifactId>
  <version>1.0.0</version>
</dependency>

to hakunapi-source-postgis causes features.war to grow from 33mb to 51mb. Might not be an issue, but not the tiniest dependency to add

[jampukka]

@tsallinen, did this

• Optionally support Azure managed identity for database authentication (instead of username/password). See https://learn.microsoft.com/en-us/azure/postgresql/flexible-server/connect-java?tabs=passwordless

also get completed?

[tsallinen]

I am unable to verify that for now, but I think we can close this issue and open a new one later if further changes are needed. Hakunapi is now ready for containers.

[teezip]

As commented above "we can close this issue and open a new one later if further changes are needed".