How can I access runtime environment variables from a webpack-compiled script that runs in node? - node.js

We package and ship a web server that runs in node, using webpack (an admittedly unusual scenario).
In this web server, I would like to access runtime environment variables, not the environment variables from the compile-time run of webpack. However, process.env just contains { NODE_ENV: 'development' }.
Is there some way of accessing the actual runtime process's environment?

The replacement of process.env is actually done by changing code that accesses that variable. If you access it programmatically in a way that avoids this, you will be able to use the underlying variable which is still present:
// avoid cunning webpack replacement of process.env code
let process_env = {}
for (var a of ['env']) {
process_env = process[a]
}
console.log(process.env.HOME) // this gives undefined
console.log(process_env.HOME) // this works

Related

NextJs activate DatadogRum depending of env

We currently have multiple environments and we would like to init datadogRum only for production.
In the _app.tsx I tried something like this :
import { datadogRum } from '#datadog/browser-rum';
if (process.env.NODE_ENV=== 'production') {
datadogRum.init({...});
datadogRum.startSessionReplayRecording();
}
But this is not working because env variables are not available here ...
Do you have any work around for this ?
I succeed using #bwest comment.
I used nextJs getInitialProps in order to transmit my env variable.
And I put my datadog init code in a useEffect(() => {...} , []) hook to only execute the code once.
With nextjs environment variables can be available to front-end code.
They will be interpolated inside your code using some webpack plugin (something like EnvironmentPlugin or DefinePlugin).
From this Nextjs documentation:
Next.js comes with built-in support for environment variables, which allows you to do the following:
Use .env.local to load environment variables
Expose environment variables to the browser by prefixing with NEXT_PUBLIC_

How to use node package dotenv to access local development environment variables in Red Hat OpenShift application?

I'm revisiting a project which hasn't been updated for a while.
In production/online environment, it uses environment variables defined at:
openshift online console > applications > deployments > my node app > environment
In development/offline environment, it uses environment variables defined at:
./src/js/my_modules/local_settings (this file is ignored by .gitignore)
The code looks something like:
// check which environment we are in
if (process.env.MONGODB_USER) {
var online_status = "online";
}
else {
var online_status = "offline";
}
// if online, use environment variables defined in red hat openshift
if (online_status === 'online') {
var site_title = process.env.SITE_TITLE;
var site_description = process.env.SITE_DESCRIPTION;
//etc
}
// if offline, get settings from a local file
else if (online_status === 'offline') {
var local_settings = require('./src/js/my_modules/local_settings');
var site_title = local_settings.SITE_TITLE;
var site_description = local_settings.SITE_DESCRIPTION;
// etc
}
I would like to install the dotenv package in my local project repo via:
npm install dotenv
So that I can:
Have my local settings in a .env file in the root of my project (ignored in .gitignore)
Be able to use process.env.SOME_VARIABLE rather than local_settings.SOME_VARIABLE
Get rid of some if/else blocks as both scenarios would point to process.env.SOME_VARIABLE
I'm a bit confused as to how this would effect the online environment.
Seeing as both production/online and development/offline environments would use:
var some_variable = process.env.SOME_VARIABLE_HERE
would the application automatically know to:
Look at the local .env file when in development?
Look at the Red Hat environment variables when in production?
And would adding the required instantiation at the beginning of the server-side file:
require('dotenv').config()
somehow make Red Hat OpenShift freak out (as it seems to already have its own 'things' in place to resolve references to process.env.SOME_VARIABLE_HERE to the relevant values defined in the OpenShift console)?
To have a file by any environment (.dev .staging .prod) into the source code repository or manually in the server (it those are in .gitignore) worked for long time, but now it goes against to the devops.
The clean way is to use environment variables but managed remotely and obtained at the start of your application.
How it works?
Basically your apps don't read or need a file (.env .properties, etc) with variables anymore. It loads them from a remote http service.
Not intrusive
In this approach, you don't need specific languages variables (nodejs in your case). You just need to prepare your app to use environment variables. Your application don't care where the variables come from, just needs to be available at operative system level.
To achieve that, you just need to download the variables using a simple shell code or a very basic algorithm (http invocation) in your favorite language.
After that, after the start of your app, variables are ready to use at the most basic level.
var site_title = process.env.SITE_TITLE;
This approach is not intrusive because your app don't need something complex like library or algorithm in some programing language. Just needs the environment variables.
Intrusive
Same as previous alternative but instead to read the variables direct from environment system, you should use or create a class/module in your language. This offer your the variables you need:
var site_title = VariablesManager.getProperty("SITE_TITLE");
VariablesManager at the startup must have consumed the variables from a remote service (http) and the store them to offer them to whoever needs it through getProperty method.
Also this VariablesManager usually has a feature called hot-reload which at intervals, update the variables consuming the remote variables manager. With this, if your application is running in production with real users and some variable needs to be updated, you just need to change it in the variables manager. Automatically your app will load the new values, without restart or touching your app
This approach is intrusive because you need to load advanced libraries in some programing language or create it.
Devops
Your application just needs a few properties or settings related to the consume of remote variables. For example: variables of acme-web-staging:
remote_variables_manager = https://variables.com/api
application_id = acme-web-staging
secure_key = *****
You could hide the secure key and parametrize the application_id using environment variables (created in the platform console)
remote_variables_manager = https://variables.com/api
application_id = ${application_id}
secure_key = ${remote_variables_manager_key}
Or if you want one variable manager by each environment
staging
remote_variables_manager = https://variables-staging.com/api
application_id = acme-web
secure_key = *****
production
remote_variables_manager = https://variables-staging.com/api
application_id = acme-web
secure_key = *****
Variables manager
This concept was introduced many years ago. I used with java. It consist in a web application with features like:
secure login
create applications
create variables of an application
crypt sensitive values
publish http endpoints to download or query the variables by application
Here a list of some ready to use alternatives:
Configurator
Nodejs & mysql solution. I developed this and I use it in various projects.
Doppler
zookeeper
http://www.therore.net/java/2015/05/03/distributed-configuration-with-zookeeper-curator-and-spring-cloud-config.html
Spring Cloud
https://www.baeldung.com/spring-cloud-configuration
This is a java spring framework functionality in which you can create properties file with configurations and configure your applications to read them.
Consul
Consul is a service mesh solution providing a full featured control plane with service discovery, configuration, and segmentation functionality.
doozerd, etcd
In your specific case
Don't use dot-env
Use pure process.env.foo
Deploy a remote variables manager in your openshift infraestructure
Create just one variable in your openshift web console: APP_ENVIRONMENT
In your code at the start, do something like this:
if (process.env.APP_ENVIRONMENT === "PROD")
//get variables from remote service using
//some http client like axios, request, etc
//then inject them to your process.env
process.env.site_url = remoteVariables.site_url
else
//we are in local developer workspace
//so, nothing complex is required
//developer should inject manually
//before the startup: npm run start or dev
//export site_url = "acme.com"
If you can configure an execution of a shell script before the start of your openshift app, you could load and expose the variables at that stage and the previous snippet would not be necessary because the variables will be ready to be retrieved using process.env directly in your app

Environment variables in NodeJs using cPanel

So I'm using cPanel with Setup Node.js App plugin for a Next.js app. (don't asky why cPanel)
Everything is working as expected in development, except for environment variables in production, I set up them manually from the cPanel interface, I restarted/stopped the app, logging the process.env on the server and I don't see the env variables there (not to say when trying to call them they are undefined).
When doing
res.json(JSON.stringify(process.env)); i get a bunch of variables except for the one I manually wrote in cPanel variables interface.
It is important for me to store these variables as secret key because they are API credentials.
Anyone know what I might have misconfigured or had this problem?
Never mind, found the answer, apparenlty was a Next.js misconfiguration. I had to add the following lines of code inside next.config.js in order to read env variables on build version.
require('dotenv').config();
module.exports = {
env: {
EMAIL_NAME: process.env.EMAIL_NAME,
EMAIL_PASSWORD: process.env.EMAIL_PASSWORD,
GETRESPONSE_API_KEY: process.env.GETRESPONSE_API_KEY
}
};
Where EMAIL_NAME, EMAIL_PASSWORD, GETRESPONSE_API_KEY were the variables defined by me on cPanel interface

Why is process.env returning an empty object, while process.env.prop returns the prop value?

So I have the simplest example on a node machine running with a react-redux app with webpack (Though I don't think any of this matters for the issue expect it being on nodejs).
Specific calls get a value pack:
console.log(process.env.NODE_ENV); // output: 'development'
General calls get nothing back:
console.log(process.env); // output: {}
What am I missing here?
Addition info the might be relevant:
I am using dotenv for the test environment.
I am using dotenv-webpack for the development environment.
I am not using neither of those for the production environment deployed to Heroku
The problem persists on all environments.
The issue with process.env variable being empty in browser is because browser doesn't have real access to the process of the node.js. It's run inside the browser though.
Usage of process.env.ANYTHING is usually achieved by plugins like https://webpack.js.org/plugins/define-plugin/ which just simply replace any occurrence of process.env.ANYTINHG with env variable during BUILD time. It really does just simple str.replace(/process.env.ANYTING/value/) this needs to be done during build time as once you output dist bundle.js you don't have access to the ENV variables.
Replacing during build time
Therefore you need to be sure that when you are producing production build e.g with yarn build you are using webpack.DefinePlugin and replacing those process.env calls with current ENV values. They can't be injected in runtime.
Injecting in runtime
When you need to access env variables in runtime it's basically impossible in JavaScript in browser. There are some sort of hacks for example for NGINX which can serialize current env variables to the window.ENV variable and in your app you will not use process.env but window.ENV. So you need to either have ENV variables available while you are building the application or build mechanism which will dynamically output current ENV as json to window and access with react. If you are using docker it can be done with ENTRYPOINT otherwise you need some bash script which will always output current ENV variables as JSON to the index.html of your app

Changing Express constant based on URL (ie localhost vs production)

I'm fairly new to node and express...
I have a constant I set in my Node/Express application for "Domain". I'm constantly switching between localhost and the actual url when I switch between development and production.
I'm trying to figure out how I can automatically test the URL so that when the code is read on the server (ie actual domain url vs localhost) that it sets the proper domain url.
Here is my code:
function define(name, value) {
Object.defineProperty(exports, name, {
value: value,
enumerable: true
});
}
define("DOMAIN", "http://www.actual_domain.com");
// define("DOMAIN", "http://localhost:3000");
Anyone have a simple solution for this?
Thanks!!
there is many solutions for this, but usually this is done by environment variables, depends on your platform, but, in Linux systems, you do the following in your shell
export ENV_URL="http://www.example.com"
and to make sure its exported successfully
echo $ENV_URL
and in your code you do
const base_url = process.env.ENV_URL || "http://www.default.com";
in your local machine you set the ENV_URL to localhost or whatever you prefer, and in your server you set it to your actual URL.
or you could simply have many configuration files and you can determine the appropriate one by the environemnt variable like
export ENV=PROD
and in your code you can load the prod configuration file that contains your environment configurations.
The de facto way to do this sort of thing is through environment variables. Have a look at 12factor.net for a load of best practices, but in general you want to put differences in the environment into environment variables, then read those variables at runtime.

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