Free Tier: Set up Helidon on an Ubuntu Instance

In this tutorial, you use an Oracle Cloud Infrastructure Free Tier account to set up an Ubuntu compute instance. Then, you set up a Helidon MicroProfile (MP) server for your host.

Key tasks include how to:

Set up a compartment for your development work.
Install your Ubuntu Linux instance and connect it to your Virtual Cloud Network (VCN).
- Set up an Oracle Cloud Infrastructure virtual cloud network and related network services required for your host to connect to the internet.
- Set up ssh encryption keys to access your Ubuntu Linux Server.
Configure ingress rules for your VCN.
Install JDK and Maven.
Set up Helidon with MicroProfile (MP) server.
Create a Hello World Java application.
Test your application.

Here is a simplified diagram of the setup for your Linux Instance.

A diagram of the components needed to run a Helidon MicroProfile server on Oracle Cloud Infrastructure

For additional information, see:

Before You Begin

To successfully complete this tutorial, you must have the following:

Requirements

An Oracle Cloud Infrastructure Free Tier account. Oracle Cloud Infrastructure Free Tier.
A MacOS, Linux, or Windows computer with ssh support installed.

1. Set up a Compartment for Development

Configure a compartment for your development.

Create a Compartment

2. Install an Ubuntu Linux Instance

Use the Create a VM Instance workflow to create a new compute instance.

The workflow does several things when installing the instance:

Creates and installs a compute instance running Ubuntu Linux.
Creates a VCN with the required subnet and components needed to connect the Ubuntu Linux instance to the internet.
Creates an ssh key pair you use to connect to the instance.

Review Installation Steps

To get started installing an instance with the Create a VM instance workflow, follow these steps:

Important

The steps provided are for a Free Tier account. If you are using a paid account, the steps might differ from those shown here.

Click the Oracle Cloud icon to go to the main landing page.
- Scroll down to Launch Resources.
- Select Create a VM instance workflow.
The Create compute instance page is displayed. The page sections include
- Name and Compartment
- Placement
- Security
- Image and shape
- Networking
- Add SSH keys
- Boot volume
Choose the Name and Compartment.
Initial Options
- Name: <name-for-the-instance>
- Create in compartment: <your-compartment-name>
Enter a value for the name or use the system supplied default. For compartment, select the compartment you created.
Review the Placement settings.
- Take the default values. An availability domain is assigned to you.
The data might look similar to the following:

Availability domain
- Availability domain: AD-1
- Capacity type: On-demand capacity
- Fault domain: Let Oracle choose the best fault domain
Note

For Free Tier, use the Always Free Eligible option for availability domain.
Review the Security settings.
- Take the default settings.
The data might look similar to the following:

Security
- Shielded instance: Disabled
- Confidential computing: Disabled
Review the Image and shape settings. Change the operating system image.
- Click Edit.
- Click Change Image.
- Click Ubuntu.
- Select Canonical Ubuntu 22.04 or a later version.
- Click Select Image.
Note

The following is sample data for an AMD virtual machine. The actual values might differ.

Image and shape
- Image: Canonical Ubuntu 22.04
- Image build: <current-build-date>
- Shape: VM.Standard.E2.1.Micro
- OCPU: 1
- Memory (GB): 1
- Network bandwidth (Gbps): 0.48
Note

For Free Tier, use Always Free Eligible shape options.
- Continue to the next section.
Review the Networking settings. Make the following changes to the default.
- Click Edit.
- Primary Network: Select Create new virtual cloud network.
- New virtual cloud network name: Take the generated VCN name or provide a name.
- Create in compartment: <your-compartment-name>.
- Subnet: Select Create new public subnet.
- New subnet name: Take the generated subnet name or provide a name.
- Create in compartment: <your-compartment-name>.
- CIDR block: Take the default value (for example, 10.0.0.0/24).
- Public IPv4 address, take the default value of Assign a public IPv4 address.
- Continue to the next section.
Review the Add SSH keys settings. Take the default values provided by the workflow.
- Select the Generate a key pair for me option.
- Click Save Private Key and Save Public Key to save the private and public SSH keys for this compute instance.
If you want to use your own SSH keys, select one of the options to provide your public key.

Note

Put your private and public key files in a safe location. You can't retrieve keys again after the compute instance has been created.
Review the Boot volume settings.

Uncheck the Specify a customer boot volume size setting.

Check the Use in-transit encryption setting.

Uncheck the Encrypt this volume with a key that you manage setting.
Click Create to create the instance. Provisioning the system might take several minutes.

You have successfully created an Ubuntu Linux instance.

3. Enable Internet Access

The Create a VM Instance wizard automatically creates a VCN for your VM. You add an ingress rule to your subnet to allow internet connections on port 8080.

Create an Ingress Rule for your VCN

4. Run an Application on Helidon Server

Next, set up Helidon on your Ubuntu Linux instance.

Configure the Ubuntu Firewall

To configure the Ubuntu firewall, follow these steps:

Open the navigation menu and click Compute. Under Compute, click Instances.
Click the link to the instance you created in the previous step.
From the Instance Details page look under the Primary VNIC section. Copy the public IP address the system created for you. You use this IP address to connect to your instance.
Open a Terminal or Command Prompt window.
Change into the directory where you stored the ssh encryption keys you created in part 2.
Connect to your instance with this SSH command.
```
ssh -i <your-private-key-file> ubuntu@<x.x.x.x>
```
Since you identified your public key when you created the instance, this command logs you into your instance. You can now issue sudo commands to install and start your server.
Update firewall settings.
The Ubuntu firewall is disabled by default. However, you must update your iptables configuration to allow HTTP traffic. Run the following commands:
iptables.
```
sudo iptables -I INPUT 6 -m state --state NEW -p tcp --dport 8080 -j ACCEPT
sudo netfilter-persistent save
```
The commands add a rule to allow HTTP traffic through port 8080 and saves the changes to the iptables configuration files.

Install OpenJDK

Run the following commands:

sudo apt update
sudo apt -y install openjdk-11-jdk-headless
java -version

Set JAVA_HOME in .bashrc.
Update the file:
```
vi .bashrc
```
In the file, append the following text and save the file:
```
# set JAVA_HOME
export JAVA_HOME=/usr/lib/jvm/java-11-openjdk-amd64
```
Activate the preceding command in the current window.
```
source ~/.bashrc
```

Install Apache Maven

Install Helidon

Run the following Maven Archetype which creates a Maven project template to start with. This project uses the Helidon MP Quickstart example from the Helidon website. Run the following commands:

Run Helidon Maven install. For example:

mvn -U archetype:generate -DinteractiveMode=false \
    -DarchetypeGroupId=io.helidon.archetypes \
    -DarchetypeArtifactId=helidon-quickstart-mp \
    -DarchetypeVersion=2.2.1 \
    -DgroupId=io.helidon.examples \
    -DartifactId=helidon-quickstart-mp \
    -Dpackage=io.helidon.examples.quickstart.mp

The Archetype creates a Maven project under the current directory. Your output is similar to the following:

[INFO] Project created from Archetype in dir: /home/ubuntu/helidon-quickstart-mp
[INFO] BUILD SUCCESS

Note

To install the latest version of Helidon MP, see Helidon MP Quickstart

Change to the helidon-quickstart-mp directory.
```
cd helidon-quickstart-mp
```
Build the application.
```
mvn package
```
You get a message of success.
```
[INFO] BUILD SUCCESS
```

Run the application.

java -jar target/helidon-quickstart-mp.jar

Test your Helidon Application

You can now test your application.

From a new terminal, connect to your Ubuntu instance with your SSH keys, and then in the command line enter:
```
curl -X GET http://localhost:8080/greet
```
Or, you can connect your browser to the public IP address assigned to your instance: http://<x.x.x.x>:8080/greet

You see {"message":"Hello World!"} on your instance, or in your browser.
Enter a name for the greeting. From the terminal, enter:
```
curl -X GET http://localhost:8080/greet/Mike
```
Or, from your browser, enter: http://<x.x.x.x>:8080/greet/Mike.

You see {"message":"Hello Mike!"} on your instance, or in your browser.

Update the greeting. From the terminal, enter:

curl -X PUT -H "Content-Type: application/json" -d '{"greeting" : "Aloha"}' http://localhost:8080/greet/greeting

The command updates the Hello in the message to Aloha.

Test the updated greeting. From the browser, enter: http://<x.x.x.x>:8080/greet/Mike.
You see {"message":"Aloha Mike!"} on your instance, or in your browser.

Enter the following commands in your browser to get health and metrics.

http://<x.x.x.x>:8080/health
http://<x.x.x.x>:8080/metrics

To get metrics in JSON, from the terminal, enter:

curl -H 'Accept: application/json' -X GET http://localhost:8080/metrics

Congratulations! You have successfully created a Hello World application using the Helidon MicroProfile service, on your Oracle Cloud Infrastructure instance.

References:

For detailed information on this example, see Helidon MP Quickstart

What's Next

You have successfully created a Hello World application using the Helidon MicroProfile service, on your Oracle Cloud Infrastructure instance.

To explore more information about development with Oracle products, check out these sites:

Oracle Cloud Infrastructure Documentation Try Free Tier

Free Tier: Set up Helidon on an Ubuntu Instance

Before You Begin 🔗

Requirements

1. Set up a Compartment for Development 🔗

2. Install an Ubuntu Linux Instance 🔗

3. Enable Internet Access 🔗

4. Run an Application on Helidon Server 🔗