Install Node Express on an Oracle Linux Instance

2 Before You Begin

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

Requirements

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

3 Set up a Compartment for Development

Configure a compartment for your development.

Create a Compartment

Create a compartment for the resources that you create in this tutorial.

1. Log in to the Oracle Cloud Infrastructure Console.
2. Open the navigation menu and click Identity & Security. Under Identity, click Compartments.
3. Click Create Compartment.
4. Fill in the following information:
   • Name: <your-compartment-name>
   • Description: Compartment for <your-description>.
   • Parent Compartment: <your-tenancy>(root)
5. Click Create Compartment.

Reference: Create a compartment

4 Install your Oracle Linux Instance

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

The wizard does several things when installing the instance:

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

Review Installation Steps

To get started installing your instance with the Create a VM Instance wizard, follow these steps:

1. From the main landing page, select Create a VM Instance wizard.

   The Create Compute Instance page is displayed. It has a section for Placement, Image and shape, Networking, Add SSH keys, and Boot volume.

2. Choose the Name and Compartment.

   Initial Options

   • Name:
   • Create in compartment:

   Enter a value for the name or leave the system supplied default.

3. Review the Placement settings. Take the default values provided by the wizard.

   The following is sample data. The actual values change over time or differ in a different data center.

   Placement

   • Availability domain: AD-1
   • Capacity type: On-demand capacity.
   • Fault domain: Oracle chooses the best placement.

   For Free Tier, use Always Free Eligible option for availability domain.

4. Review the Image and shape settings. Take the default values provided by the wizard.

   The following is sample data. The actual values change over time or differ in a different data center.

   Image

   • Image: Oracle Linux 7.9
   • Image build: 2020.11.10-1

   Shape

   • Shape: VM.Standard.E2.1.Micro
   • OCPU count: 1
   • Memory (GB): 1

   • Network bandwidth (Gbps): 0.48

     Note: For Free Tier, use Always Free Eligible shape options.

5. Review the Networking settings. Take the default values provided by the wizard.

   The following is sample data. The actual values change over time or differ in a different data center.

   • Virtual cloud network: vcn-<date>-<time>
   • Subnet: vcn-<date>-<time>
   • Assign a public IPv4 address: Yes

6. Review the Add SSH keys settings. Take the default values provided by the wizard.

   • 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.

   Put your private and public key files in a safe location. You cannot retrieve keys again after the compute instance has been created.

7. Review the Boot volume settings. Take the default values provided by the wizard.

   Leave all check boxes unchecked.

8. Click Create to create the instance. Provisioning the system might take several minutes. You have successfully created an Oracle Linux instance.

5 Enable Internet Access

The Create a VM Instance wizard automatically creates a VCN for your instance. You add an ingress rule to your subnet to allow internet connections on port 3000.

Create an Ingress Rule for your VCN

Follow these steps to select your VCN’s public subnet and add the ingress rule.

1. Open the navigation menu and click Networking, and then click Virtual Cloud Networks.
2. Select the VCN you created with your compute instance.

3. With your new VCN displayed, click <your-subnet-name> subnet link.

   The public subnet information is displayed with the Security Lists at the bottom of the page. A link to the Default Security List for your VCN is displayed.

4. Click the Default Security List link.

   The default Ingress Rules for your VCN are displayed.

5. Click Add Ingress Rules.

   An Add Ingress Rules dialog is displayed.

6. Fill in the ingress rule with the following information.

   Fill in the ingress rule as follows:

   • Stateless: Checked
   • Source Type: CIDR
   • Source CIDR: 0.0.0.0/0
   • IP Protocol: TCP
   • Source port range: (leave-blank)
   • Destination Port Range: 3000
   • Description: Allow HTTP connections
7. Click Add Ingress Rule.

Now HTTP connections are allowed. Your VCN is configured for Node Express.

You have successfully created an ingress rule that makes your instance available from the internet.

6 Create a Node Express Application

Next, set up an Express framework on your Oracle Linux instance and then create and run a NodeJS application.

Install and Set up Node Express

Follow these steps to set up your instance and build your application:

1. Open the navigation menu and click Compute. Under Compute, click Instances.

2. Click the link to the instance you created in the previous step.

   From the Instance Details page look in the Instance Access section. Copy the public IP address the system created for you. You use this IP address to connect to your instance.

3. Open a Terminal or Command Prompt window.
4. Change into the directory where you stored the ssh encryption keys you created for this tutorial.

5. Connect to your instance with this SSH command:

    $ ssh -i <your-private-key-file> opc@<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.

6. Enable HTTP connection on port 3000.

    $ sudo firewall-cmd --permanent --add-port=3000/tcp
                        $ sudo firewall-cmd --reload
                       

7. Install the latest version of NodeJS.

    $ sudo yum update
                        $ sudo yum install -y oracle-nodejs-release-el7
                        $ sudo yum install -y nodejs
                        $ node --version
                       

8. Create a directory for your application.

    $ mkdir node-hello-app
                       

9. Change to the node-hello-app directory.

    $ cd node-hello-app
                       

10. Use npm to create a package.json file:

    $ npm init
                        

    Enter information as follows:

    • name: node-hello-app
    • version: 1.0.0
    • description: Node Express Hello application
    • entry point: app.js (Don’t use the default.)
    • test command: (leave-blank)
    • git repository: git://github.com/username/repository.git (or replace with a valid git repository)
    • keywords: (leave-blank)
    • author: Example User username@example.com
    • license: UPL-1.0

    Preview what you get in package.json.

    About to write to /home/opc/node-hello-app/package.json:
                            
                        {
                          "name": "node-hello-app",
                          "version": "1.0.0",
                          "description": "Node Express Hello application",
                          "main": "app.js",
                          "scripts": {
                            "test": "echo \"Error: no test specified\" && exit 1"
                          },
                          "repository": {
                            "type": "git",
                            "url": "git://github.com/username/repository.git"
                          },
                          "author": "Example User username@example.com",
                          "license": "UPL-1.0",
                          "bugs": {
                            "url": "https://github.com/username/repository/issues"
                          },
                          "homepage": "https://github.com/username/repository#readme"
                        }
                        

    Enter yes to approve your answers.

11. Install Express and save it in the dependencies list of package.json.

    $ npm install express --save
                        

12. Verify that express is added as a dependency in package.json.

    $ cat package.json
                            
                        "dependencies": {
                            "express": "^4.17.1"
                        }
                        

13. Create a “Hello, World!” application.

    Create the file:

    $ vi app.js
                        

    In the file, input the following text and save the file:

    const express = require('express')
                        const app = express()
                        
                        app.get('/', function (req, res) {
                          res.send('Hello World!')
                        })
                        
                        app.listen(3000, function() {
                          console.log('Hello World app listening on port 3000!');
                        })
                        

14. Run the NodeJS program:

    $ node app.js
                        

15. Test the application using the command line or a browser:

    • To test with curl, 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:3000
    • From a browser, connect to the public IP address assigned to your instance: http://<x.x.x.x>:3000

    The Node app returns Hello World! on your instance, or in your browser.

You have successfully created a local NodeJS application in an Express framework, on an Oracle Cloud Infrastructure instance.

References:

For more information on Express, see:

• Installing Express
• Getting Started with Express

7 What's Next

You have successfully installed and deployed a Node Express app on Oracle Cloud Infrastructure using a Linux instance.

To explore more information about development with Oracle products:

• Oracle Developers Portal
• Oracle Cloud Infrastructure