Connect to Oracle ATP database using Node.js

In this week series I will explore the capabilities of Oracle Autonomous Transaction Processing (ATP) database beyond connecting to SQL developer.

There are several ways to achieve this, however this is the simplest way to show the capabilities/possibilities that can be attained. 

Prerequisites:

  • Node.js installed in your computer
  • node-oracledb library
  • Oracle Instant Client
  • Oracle ATP database

Installing the Oracle Instant Client in Windows OS

We need the Oracle Instant client to connect and run remote Oracle databases in Node.js.

Download and install the Oracle Instant Client.

Unzip the package into a single directory ie. C:\oracle\instantclient_18_5

Set the environment variable PATH to include the path that you created.

Download the ATP Database connection Wallet.

Log in to your ATP database and download your credential wallet. This contains your connection information to your Oracle ATP database.

ATP1

Extract the wallet files in a given folder. Mine are in:

C:\wallets

We need to update the sqlnet.ora & ojdbc.properties  files in the wallet folder to reflect the location of the wallet.

In ojdbc.properties file:

oracle.net.wallet_location=(SOURCE=(METHOD=FILE)(METHOD_DATA=(DIRECTORY="c:\wallets")))

sqlnet.ora:

WALLET_LOCATION = (SOURCE = (METHOD = file) (METHOD_DATA = (DIRECTORY="c:\wallets")))
SSL_SERVER_DN_MATCH=yes

Set the TNS_ADIMN variable:

Since we are using Node.js we can define the Environment variables in an .env configurations file many thanks to the custom-env node library.

ATP2

Install these Node.js libraries to help you run the connection. (Each of the libraries below has their specific functions- We shall see on a later post)

npm install oracledb
npm install async
npm install app
npm install express

You can create a simple testconnection.js file to confirm that the connection to ATP database is working. This file requires an .env configurations file and the dbconfig.js file.

require ('custom-env').env('stagging') //find the .env.stagging file and place the right location of your wallet

console.log(process.env.TNS_ADMIN)

var oracledb = require('oracledb');

var dbConfig = require('./dbconfig.js');

let error;

let user;

oracledb.getConnection({

user: dbConfig.dbuser,

password: dbConfig.dbpassword,

connectString: dbConfig.connectString

},

function(err, connection) {

if (err) {

error = err;

return;

}

connection.execute('select user from dual', [], function(err, result) {

if (err) {

error = err;

return;

}

user = result.rows[0][0];

console.log('Connection test succeeded. You connected to ATP as ' + user + '!');

error = null;

connection.close(function(err) {

if (err) {

console.log(err);

}

});

})

}

);
The dbconfig.js file:
 
module.exports= {

dbuser: 'admin',

dbpassword: 'Your Password',

connectString: 'YourDatabaseName_TP'

}

The .env configurations file helps you load the Node.js app environment variable configurations on different environments. ie. on my .env.stagging file i have:

TNS_ADMIN='c:\wallets' 

Run the testconnection.js file:

node testconnection.js 

ATP3

We succeeded in connecting to the ATP database using Node.js.

Installing the Oracle Instant Client in Oracle Linux

Download a “Basic” or “Basic Light” zip file matching your architecture.

Unzip the package in the folder that is accessible to your application

mkdir -p /opt/oracle
cd /opt/oracle
unzip instantclient-basic-linux.x64-12.2.0.1.0.zip

Install the libaio package as root.

sudo yum install libaio

If there is no other Oracle software on the machine that will be impacted, permanently add Instant Client to the run time link path

sudo sh -c "echo /opt/oracle/instantclient_18_3 > /etc/ld.so.conf.d/oracle-instantclient.conf"
sudo ldconfig

Else set an environment variable LD_LIBRARY_PATH   to the directory of the Instant Client.

export LD_LIBRARY_PATH=/opt/oracle/instantclient_18_3:$LD_LIBRARY_PATH

Co locate the ATP connection wallet with the Instant client, create a network/admin subdirectory if it does not exist.

mkdir -p /opt/oracle/instantclient_12_2/network/admin

Edit the sql.ora file to reflect the directory “?/network/admin”

linux1

Load your Node.js files as shown previously. Test to see if your connection worked!

linux2

On the next post we shall explore how we can use this ability to connect an Oracle Digital Assistant with ATP database using a custom component.

References:

 

Thank you and Happy coding! If you liked it, share it!

This blog reflects  my own thoughts and doesn’t reflect the thoughts of my employer.

 

 

 

Run Node.js Applications on Oracle Cloud Infrastructure using PM2

Prerequisites:

What is PM2?

Pm2 is a production process manager for Node.js applications with built-in load balancer. It allows you to keep you applications alive forever, reloads them at zero downtime. It’s simple to use and makes managing a production environment seamless.

Starting a node app in pm2 is as easy as;

$ pm2 start app.js

Installing PM2 on Oracle Compute;

First, you need to take care of your firewall and open the necessary ports.

Login to your compute instance on OCI through cmd and open the ports you want to use using the firewalld command.

First install firewalld (If not yet installed)

 sudo yum install firewalld

Next expose port you want to use ie.5001 to the public to allow in-bound web traffic via HTTP. (Adding it on the public zone)

sudo firewall-cmd --zone=public --add-port=5001/tcp --permanent

Reload the firewalld – you can even check the features enabled on the public zone.

sudo firewall-cmd --reload
sudo firewall-cmd --info-zone public

node1

Now that we have exposed port 5001 to the public, lets now install PM2. It’s a piece of cake! Run;

npm install pm2 -g

On your node application, specify the port you exposed.

node2

Run your app using pm2 start command (My node app is saved as app.js)

pm2 start app.js

node3

You can now test your Node.js app on your browser using the public IP address and the port you exposed;

 <your compute instance public IP address>: <port>

node4

It works! Note that you can run more than one Node.js application using PM2, just expose them in different ports.

Finally a few other PM2 commands and resources to keep you going.

pm2 ls — Show a list of all applications
pm2 stop <app> — Stops a specific application
pm2 start <app> — Starts a specific application
pm2 <app> scale N — Scales the application you specify to N number of instances (can be used to scale up or down)
pm2 kill — Kills all running applications
pm2 restart — Restarts all running applications
pm2 reload — Reloads the app configuration
pm2 monit -will return a rich set of data around your application’s health
pm2 logs — Outputs logs from all running applications
pm2 logs app — Outputs logs from only the app application
pm2 flush — Flushes all log data, freeing up disk space

Final thoughts;

Pm2 is an amazing open source project. Many thanks to everyone putting all the resources out there!

If you need any support feel free to reach out, or if you have any additional tips and tricks, feel free to share with me!

Here are additional resources and references:

 

Thank you and Happy coding! If you liked it, share!

This blog reflects  my own thoughts and doesn’t reflect the thoughts of my employer.