Add support for multiple databases

[kdhrubo]

Discussed in #458

^{Originally posted by MichalisDBA April 12, 2024}
Hello.

I do not know if you have this on the roadmap. I'll just give you my idea on how i envision to work with multiple data sources running a single instance of db2rest.

Create a config file. Let's say datasources.conf

Inside this configuration file have the following settings:

db2rest:
	SERVER_PORT: 8090

java:
	-Xms2048m
	-Xmx8192m

db1:
	service:
		DRIVER: ORACLE
		USERNAME: USER
		PASSWORD: PASS
		SERVER: IP / FQDN
		INSTANCE: MY_INSTANCE
		SCHEMA: MY_SCHEMA #optional
		TABLES: [TABLE1, TABLE2] #optional
	env:
		ENABLE_DATETIME_FORMATTING: true
		TIME_FORMAT: HH:mm:ss
		DATE_FORMAT: dd-MM-yyyy
		DATE_TIME_FORMAT: "dd-MM-yyyy HH:mm:ss"
	jdbc:
		oracle.jdbc.timezoneAsRegion: false

db2:
	service:
		DRIVER: MYSQL
		USERNAME: USER
		PASSWORD: PASS
		SERVER: IP / FQDN
		DATABASE: MY_DATABASE
		TABLES: [TABLE1, TABLE2] #optional
	env:
		ENABLE_DATETIME_FORMATTING: true
		TIME_FORMAT: HH:mm:ss
		DATE_FORMAT: dd-MM-yyyy
		DATE_TIME_FORMAT: "dd-MM-yyyy HH:mm:ss"
	jdbc:
		oracle.jdbc.timezoneAsRegion: false

Then you can run db2rest like that:

java --config=datasources.conf -jar db2rest.jar

When the application starts you can query the different data sources like that

http://localhost:8090/db1/my_table/?

http://localhost:8090/db2/my_view/?

Something like that.