Docker environment variables, dokku-redis - node.js

Using redis as my session store in my express.js app. I'm having problems. Narrowed them down to a connection issue.
How do I access a docker environment variable from within an express.js app? I'm using dokku-redis.
It reports that environment variables are automatically set up on the linked app... I've linked my app. running dokku redis:info foo shows that all is linked. I'm trying to pull in REDIS_URL
Thanks, Rob
https://github.com/dokku/dokku-redis
------------
a redis service can be linked to a
container this will use native docker
links via the docker-options plugin
here we link it to our 'playground' app
NOTE: this will restart your app
dokku redis:link lolipop playground
the following environment variables will be set automatically by docker (not on the app itself, so they won’t be listed when calling dokku config)
DOKKU_REDIS_LOLIPOP_NAME=/lolipop/DATABASE
DOKKU_REDIS_LOLIPOP_PORT=tcp://172.17.0.1:6379
DOKKU_REDIS_LOLIPOP_PORT_6379_TCP=tcp://172.17.0.1:6379
DOKKU_REDIS_LOLIPOP_PORT_6379_TCP_PROTO=tcp
DOKKU_REDIS_LOLIPOP_PORT_6379_TCP_PORT=6379
DOKKU_REDIS_LOLIPOP_PORT_6379_TCP_ADDR=172.17.0.1
and the following will be set on the linked application by default
REDIS_URL=redis://lolipop:SOME_PASSWORD#dokku-redis-lolipop:6379
NOTE: the host exposed here only works internally in docker containers. If
you want your container to be reachable from outside, you should use 'expose'.
------------------------------
Edit - sorry, I forgot to add that I have tried process.env

How did you link the redis service with your application? You cannot simply do dokku config:set, and if you did, you should unset it and then use dokku redis:link instead. Once you do that, rebuild your app using dokku ps:rebuild APP and you should get process.env.REDIS_URL set.

you can access environment variables through process.env like the following:
console.log(process.env["DOKKU_REDIS_LOLIPOP_NAME"]);
console.log(process.env["DOKKU_REDIS_LOLIPOP_PORT"]);
console.log(process.env["REDIS_URL"]);
also as long as keys in objects do not harm variable naming conventions you can access them like this too:
console.log(process.env.REDIS_URL);
more info in regards to javascript variable naming rules: What characters are valid for JavaScript variable names?

Related

Handle multiple environments variables in .env NodeJs

Suppose I have a .env file like these:
#dev variable
PORT=3000
#production
PORT=3030
And I get these variables using process.env, how can I manage to sometimes use the dev variable and other times the Production variable
You can create multiple .env files like .dev.env, .prod.env, and load them based on NODE_ENV. using this
Storing configuration in environment variables is the way to go, and exactly what is recommended by the config in the 12-Factor App, so you're already starting with the right foot.
The values of these variables should not be stored with the code, except maybe the ones for your local development environment, which you can even assume as the default values:
port = process.env.PORT || '3000';
For all other environments, the values should be stored in a safe place like Vault or AWS Secrets Manager, and then are only handled by your deployment pipeline. Jenkins, for example, has a credentials plugin to handle that.

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

Using System environment variables in node / react with docker

I have a react app (CRA) it will be running inside a docker container for which I will set an environment variable "API_KEY" = "some_value". For the example of windows this is System Properties -> Environment Variables -> System Variables -> Variable = "API_KEY" and Value = "some_value".
I would like to access to get this variable into the application at run time. This is for the API_KEY for Azure App Insights.
https://learn.microsoft.com/en-us/azure/application-insights/app-insights-javascript#add-the-sdk-script-to-your-app-or-web-pages
The above link shows the <your instrumentation key>. I will be deploying the same application to multiple environments. Each instance of the application will need to use its specific App Insights. So the goal here is to specify that API_KEY in the environment variables which will be different for each of the docker containers.
Please note I am aware of nodeJs and process.env.API_KEY but this does not read from the systems environment variables. Is there a way to get the system variable to link up to the process.env for the node instance?
-PS this request is to an API service that will need to fire straight away. So making an API request to get it is out of the question. It will be exposed to the end client as it is logging JavaScript events for each client.
The answer is NO. You can not read system environment variables. You can however set process environment variables in a *.env file. In my case I will generate this env file via a shell script which will be triggered by the Dockerfile. This will then scrap the process for it's environment variables that start with "REACT_APP_#".
Hope this helps others.
Generating shell script
https://medium.com/#vietgoeswest/passing-env-variables-from-the-server-to-your-create-react-app-c87578a45358
Setting up env with CRA
https://medium.com/#tacomanator/environments-with-create-react-app-7b645312c09d
Dockerizing a Node.js web app
https://nodejs.org/en/docs/guides/nodejs-docker-webapp/
Passing environment variables from Docker to Node https://medium.com/#felipedutratine/pass-environment-variables-from-docker-to-my-nodejs-or-golang-app-a1f2ddec31f5
Also helpful
https://github.com/facebook/create-react-app/issues/982

How can I set up a node app (ember app kit) on heroku that reads ENV variables and makes the values available to the application?

Okay, I'm new to node, and really only just using the node server to serve static js, but I can't find any info on this anywhere.
I'm running an application ember app kit, which gets built to a node server.js for deploy, and heroku runs it with node server.js.
It uses grunt for building, testing, etc.
I'd like to know how I can specify configuration variables (i.e. authentication tokens) that can be overridden by heroku config variables.
The closest I've been able to get is a custom task that reads environment variables and writes out a json file that gets built into the site (and assigned to a global var). This works locally, but doesn't take into account heroku configs.
I even wrote a deploy script that gets heroku's configs, exports them as environment variables locally, and does the build--Which works, but the configs only get updated on app deploy. So if I do a heroku config:add CONFIG_TEST=test_value, my app doesn't see that value for CONFIG_TEST until the next time I deploy the app.
I'd like for my app to start embedding that config value in the browser JS immediately.
Any way to do this with node the way my app is set up?
I am not sure I understand what's wrong with simply taking config variables, at run time, from the environment. Use process.env.KEY in your code, and embed that result into whatever template you may have, and serve that as the result.
When you change Heroku config variables your process gets restarted, so it picks up the new values.
Is the problem the fact that you serve static files? If so -- can you simply change it so that you use a template engine to do some processing on them before serving?
OK, here's a solution for ember-app-kit using grunt-sed.
In EMBER_APP_KIT_PROJECT/tasks/options/sed.js
Add something like
module.exports = {
version: {
path: "./dist/",
pattern: '{{env.API_BASE_PATH}}',
replacement: function(){
return process.env.API_BASE_PATH;
},
recursive: true
}
};
then in your code just put
"{{env.API_BASE_PATH}}"
Now, when you run
$ grunt sed
it will replace "{{env.API_BASE_PATH}}" with whatever's in the environment variable.

Change configuration in runtime by changing environment variables using the module node-config

I'm trying to use the node-config module to change some parameters of my configuration (basically logging level) during runtime.
In the official documentation says:
Environment variables can be used to override file configurations. Any environment variable that starts with $CONFIG_ is set into the CONFIG object.
I've checked that this is true when the server starts but it does not seem to work once it's up. (The handler of the watch function is never called when an environment variable is changed unlike a change in the runtime.json file or directly changing a config variable).
I'm currently watching the whole CONFIG object like this:
var CONFIG = require('config');
CONFIG.watch( CONFIG , null , function(object, propertyName, priorValue, newValue){
console.log("Configuration change detected");
});
Does anyone know if this is possible?
The environment is available during startup of a process.
If the process is running, you won't be able to change the environment anymore, the process is in.
The only option is to restart the process or use other mechanisms to communicate with it.
Say for example having a rest or tcp listener inside, where you can transfer your variable inside.
Best regards
Robert
As you must knowing, React is a single page application which is eventually when it is complied is a static page app that means all the files of the react application is complied into vanilla JS and CSS file bundle in a Tarball. Now that Tarball is eventually deployed on a web server. It could be Apache web server, nginx web server or anything which you are using it but an important point is the static app is running in someone else browser and someone access to website CSS and JS are downloaded in a browser and it is running in the browser runtime environment so technically you cannot have a runtime environment variable for someone else browser but may be there would be a way to access them during runtime.
SOLUTION
I have achieved this goal with the package called runtime-cra.
follow the steps on this official documentation: https://blog.risingstack.com/create-react-app-runtime-env-cra/

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