Setting up the React Application
(You can skip this section if you already have a React app running.)
To build your React application, ensure you have node, npm, and npx installed. You can verify with the following commands:
If installed correctly these will both give you a number as an output.
After installed, go to a folder and run the following command
npx create-react-app [app_name] (where
[app_name] is the name of your
application). This will create a new React app in the folder ‘[app_name]‘.
Once your app is finished installing, go into your directory with the command
cd [app_name], and run the command
npm start. This will open the React
application on your computer at
http://localhost:3000. You can now go in and
change the title of the page or make another change to your React application to
see the changes in effect.
Summary of Steps:
npx create-react-app [app_name]
Listed below is an example Layerfile for webapp.io which you can use to setup a basic React application. We’ll breakdown this Layerfile in the section below for a set of detailed explanation on what each one of the instructions do.
# Set the image FROM vm/ubuntu:18.04 MEMORY 2G RUN curl -sL https://deb.nodesource.com/setup_12.x | sudo -E bash - RUN sudo apt-get install -y nodejs RUN sudo npm install [email protected] -g ENV NODE_OPTIONS=--max-old-space-size=8192 COPY . . RUN npm install RUN BACKGROUND npm start EXPOSE WEBSITE http://localhost:3000
Setting up the Layerfile
If you haven’t already, please sign up to webapp.io, and install webapp.io onto your repository.
First let’s breakdown each instruction in our Layerfile.
1: Set the Image
FROM instruction tells webapp.io what base to use to run tests from. There
can only be one
FROM line, and in this case we’re using the
virtual machine image.
If you’re familiar with AWS Ec2 Instances, this is similar to creating a virtual machine from the ubuntu 18.04 image.
2: Set the Memory
MEMORY instruction allows you to specify how much memory your environment
uses. In this case we use
MEMORY 2G to ensure that at least 2GB of memory are
3. Install NodeJS and NPM
RUN curl -sL https://deb.nodesource.com/setup_12.x | sudo -E bash -
RUN sudo apt-get install -y nodejs
RUN sudo npm install [email protected] -g
RUN instruction will run the given script, and fails the Layerfile if the
script fails. In this case, we’re using the
RUN command to install the
dependencies we need to build and run the React application.
In this case we’re using the
RUN instruction to download Node JS and npm.
4. Set Node Space Size
ENV instruction persistently sets environment variables in the Layerfile.
In this case, the
NODE_OPTIONS gets set to a specific size so that it can be
consumed later in the React start process.
5. Get Repository Files
COPY . .
COPY instruction moves files from your repository to the virtual machine.
The Layerfile will pick up on the files in the repository that you are making
the commit for, and will copy those files into the virtual machine so you can
run you project.
6. Install Dependencies
RUN npm install
Similar to the
RUN commands above, this will execute the given script
npm install, which will install the dependencies for the React app.
7. Start the React app
RUN BACKGROUND npm start
RUN BACKGROUND instruction is the
instruction with the
BACKGROUND flag. This tells webapp.io to continue to the
next step in the Layerfile instead of waiting for the given script to run. The
reason why we do this is that
npm start will essentially block the terminal
while the React app is running. We want to continue to the next step so that’s
why we use
RUN BACKGROUND here.
8. Expose React App on the Virtual Machine
EXPOSE WEBSITE http://localhost:3000
EXPOSE WEBSITE instruction creates
a link to view the virtual machine at a specific port. We use
to expose the virtual machine on port 3000 which is where the React application
runs after running
npm start. We use
EXPOSE WEBSITE here so we can get a
link to our React app to share with stakeholders involved in our projects.
Adding the Layerfile
The last step in this process is to add the Layerfile to your repository. Simply
create a file called
Layerfile (no file extension) in the root of your React
application. If you haven’t already, install webapp.io onto your repository
containing your React app. Once done, simply create a commit and push your React
app to the repository with the new Layerfile. Webapp.io will pick up on the
Layerfile and build your React application according to the steps in your
Check out our React video tutorial for a step-by-step breakdown on how to set up webapp.io with preview environments for a React application: