Currently I am developing a react application. I have created a .env file and am using the environment variables in all other pages but am not able to see the .env file in the build folder. Is there any way to change the environment variables at run time in the build file?
This will work when changing the hostname and port, etc. manually and then cresting the build. Is there any way to change the variables after creation of the build?
Any help will appropriated.
Thanks,
Riya
The answer to your question can be found here:
Create React App Docs: Adding Custom Environment Variables
The environment variables are embedded during the build time. Since Create React App produces a static HTML/CSS/JS bundle, it can’t possibly read them at runtime. To read them at runtime, you would need to load HTML into memory on the server and replace placeholders in runtime, just like described here. Alternatively you can rebuild the app on the server anytime you change them.
Related
The build version is working perfectly but can't see where it stores the environment variables. Are they hidden or visible to everyone ?
The Create React App (Webpack) build process "folds" the environment variables into constants in the source, and things are bundled as per usual after that.
They're visible to anyone who looks at your app's script files in their browser's View Source or Inspector views.
Currently when building our react application, we are using Webpack like so
new webpack.DefinePlugin({
'process.env': {
REACT_APP_BASE_URL: JSON.stringify(process.env.REACT_APP_BASE_URL),
... 20 more lines,
So, these parameters are supplied at build time, the react application is built to static file and then served with an nginx that we have full control
Through out the application, we use process.env.REACT_APP_BASE_URL and those 20 more process.env.x variables.
Previously, for each runtime environment, we need to build the application again and provide respective parameters at build time. Now we are trying to build once and insert these parameters at deploy time.
My question is what is the most feasible way to provide those variable at deploy time with the least impact/change to our current source code?
make different .env file like .env.production, .env.qa and user it in script of package.js enter link description here
I have an app ready for production. For it to work, each client needs to set a unique url to access their data. How would i prepare the app for making it easy to add a url as an access point to the clients?
Would a correct way to do this be to add it in the manifest.json file and somehow reference it from there? (Until now in development i've only used a global URL in a js file)
You need to install the package dotenv package and create a .env file in your root directory which should contain your environment variables.
Assuming that the URl you are referring to is http://localhost:3000/some/url on your localhost, then your .env file might look like:
MY_URL=http://localhost:3000/some/url
Then in your react application, you can get the value of MY_URL by doing:
const url = process.env.MY_URL
Note that if you are using the create-react-app package, then you do not need to install the dotenv package since it already comes with the create-react-app package. Also you need to change it:
REACT_APP_MY_URL=http://localhost:3000/some/url
Also make sure to add the .env file to your .gitignore file so that you do not push it to your repo.
Assuming that you are deploying your application to Heroku. Heroku provides a simple interface which allows you to add your environment variables which looks like:
That's it.
Maybe you could store them in environment variables?
that way you can always edit them later without having to change components.
Relatively new to working with react. I have an application that is working fine in local docker. I populate a bunch of REACT_APP_ environment variables by exporting them to the environment before starting the docker container.
Now, I'm trying to deploy this to a kubernetes pod by running a yarn build and then serving up the build. I see that the environment variables are available on the pod itself by looking at printenv but the application doesn't appear to be picking them up.
Is there something special with serving a production build of a react-app to get it to see the exported environment variables that I'm missing?
I don't want to embed an .env file into the built docker image for security reasons, so I'm hoping that running a react build via serve can still pick up exported REACT_APP_ environment variables that are set via kubernetes secrets.
So apparently, whenever you build a react application with npm, static files are produced that don't know anything about any environment variables you may try to inject at runtime with Kubernetes.
The article below does a good job of explaining this and why they choose to attach the environment variables to the JavaScript window object since it has application-scope available to it.
Making a React application container environment-aware at Kubernetes deployment
How to use the production version of a react or angular project and run without a local server?
( like opening from index.html or something similar)
I want to make a static web application that uses react or angular 2 as a starting point. Eventually, this will be dynamic so it make sense to take advantage of either.
I don't mind using local http-serve to serve the html and css pages in development but due to some restrictions i won't be able to set up a local server or run npm start from the terminal.
I did a lot of research but never found a definitive answer as to
So like How to use the production version of a react or angular project and run without a local server?
( like opening from index.html or something similar
React (same as Angular) is a client-side library/framework. So all you have to do is to bundle your application to a single .js file. That file will probably include React/Angular and you may just load it in your HTML file. You definitely don't need a http-serve for that. It is possible to deploy your index.html and your bundle.js file to a shared hosting and just load the app.