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Run on Droplet

Droplets are linux based virtual machines provided by DigitalOcean. Follow the instructions here to launch an Ubuntu based droplet.

tip

The droplet should be created in the same DigitalOcean region in which the database has been created.

Launch Droplet Console​

From the droplet dashboard, click on console to connect to the droplet from the browser.

Launch console

Droplet console

Install Java 21​

DB2Rest requires Java 21 to run. It makes use of virtual threads allowing very high scaling with minimal resources. Installing Java 21 on Ubuntu Droplet is very easy and only takes a single command

$ apt install openjdk-21-jre-headless

Jav 21 runtime will be installed within few seconds.

Verify JRE​

Run the command below to verify that Java Runtime 21 has been successfully installed.

$ java -version

This will print the Java version as shown below:

Verify Java

Download DB2Rest​

Next download DB2Rest using the following command:

$ wget https://download.db2rest.com/db2rest-0.3.1-FIXED.jar

In order to make the downloaded jar executable run the command below:

$ chmod +x db2rest-0.3.1-FIXED.jar

Enable Droplet IP on Database Firewall​

The droplet IP address must be enabled on the database firewall/trusted sources. Otherwise, it will not be able to connect to the database. Go to the dashboard of the database created in the previous tutorial and then in the Settings tab.

Click on Edit in the Trusted Sources section. Then select the droplet from the drop-down and click 'Save'.

Enable droplet on DB firewall

Run DB2Rest​

Finally, it's time to launch DB2Rest on the droplet. Set the environment variables as shown below:

$ export DB_URL=jdbc:postgresql://[DB_HOST]:[DB_PORT]/[DB_NAME]?currentSchema=public

$ export DB_USER=doadmin

$ export DB_PASSWORD=[DB_PASSWORD]


tip

The values of the variables are available in the database console.

Finally, run DB2Rest with the following command

$ java -jar db2rest-0.3.1-FIXED.jar

Run on Droplet

DB2Rest is started in few seconds and APIs are ready.

Test DB2Rest​


curl --request GET \
--url http://[DROPLET_IP]:8080/actuator/health \
--header 'User-Agent: insomnia/8.6.1'


The actuator health check service in DB2Rest will return the following response:

HTTP/1.1 200
Content-Type: application/json
Transfer-Encoding: chunked

{
	"status": "UP"
}

info

The response is slightly different from when, DB2Rest runs in a container platform like DigitalOcean App platform.

Query using DB2Rest​


curl --request GET \
--url http://[DROPLET_IP]:8080/employee \
--header 'User-Agent: insomnia/8.6.1'


The response is:

HTTP/1.1 200
Content-Type: application/json
Transfer-Encoding: chunked

[
	{
		"id": 1,
		"first_name": "Salman",
		"last_name": "Khan",
		"email": "[email protected]",
		"created_on": "2015-04-14T11:07:36.639+00:00"
	}
]

Security​

The steps above uses root user. In a production grade set up a different user with lesser privileges should be used. The DB2Rest jar should be copied in a folder like /opt.