Automate Static Site Deployment on S3 with AWS CodeBuild

Automated Pipeline Flow Diagram

As if the cost benefit wasn’t enough, S3 provides high availability, infinite scalability and can literally be setup in a matter of minutes. This makes it the ideal go to solution when it comes to hosting Single Page Applications (SPAs) like VueJS or ReactJS sites.

As easy as it is, it can get quite mundane updating your sites and managing environments using the console. As a developer I’m more comfortable handling such things from the comfort of my terminal and code editor.

That’s why I decided to find a solution which automates building and deploying of static sites while handling multiple environments with grace

I’m going to show you how to setup a code pipeline which pulls data form from your github repo and bundles the code via tha “npm build” command using the appropriate environmental variables and uploads the site to AWS S3. So let’s get started …

Code (React)

Let’s start with the code itself. I already have a simple react app setup and pushed to github. You can find the repo here.

We’ll be using the dotenv npm package. You can install it with this command

npm install dotenv

Then you’ll want to create .env files for each environment you want. I usually setup three of .env files namely;

  • .env.development
  • .env.staging
  • .env.production.

An important thing to remember is that every variable in the .env files must start with REACT_APP, something like this;

If you’re using Vue, with vue-cli 3. Then you don’t need the dotenv package. Just create the .env files and name your variable appropriately, e.g. VUE_APP_ENVIRONMENT

In the package.json file, change the start and build scripts to accommodate the new .env files.

“start:dev”: “sh -ac ‘. ./.env.development; react-scripts start’;”,
“build:dev”: “sh -ac ‘. ./.env.development; react-scripts build’;”,
“build:stage”: “sh -ac ‘. ./.env.staging; react-scripts build’;”,
“build:prod”: “sh -ac ‘. ./.env.production; react-scripts build’;”,

Now instead of the usual “npm start” you’ll need “npm start:dev” and react will use the .env variables for development while running locally. 👍

The last thing we need to do is add a file named “buildspec.yml”. This file is used by AWS CodeBuild to install npm, run it and bundle the code for appropriate environments. We’ll come back to it later.

S3 Bucket

So far so good let’s create the S3 bucket that’ll house our website for everyone to marvel at 😉.

Since you’ll want your website attached to a domain name, you’ll want to name your bucket the same as you domain.

Click on “Create Bucket”, name it the same as your domain and give it public read access. Once its created you’ll need to configure the bucket for website hosting.

1) Click Create Bucket → 2) Name bucket same as domain

Website Hosting

To host a static website, you configure an Amazon S3 bucket for website hosting, and then upload your website content to the bucket. This bucket must have public read access. Go to “Properties ” tab and click the “Static Website Hosting” card.

1) Go to Properties Tab → 2) Click Static Website Hosting

The panel shown above will open. Just fill it out as it is in the picture and your bucket is ready to host a static website. But we’re not done yet 😦 !

Policy Generator

The last thing we need to do is create a “Bucket Policy”, so that other AWS apps (CodeBuild) can access and perform actions on your bucket. Follow the Diagrams below to complete the S3 setup.

1) Go to Permissions Tab → 2) Click on Policy Generator → 3) Copy bucket arn

The above image shows where you enter the bucket policy. Copy the arn, labeled 3, then click on “policy generator.

1) Select Policy type → 2) Fill Add Statement Options

Here is where you create the bucket policy. Enter the following value in the Add Statement section;

  • policy type → S3
  • Effect → Allow
  • Principal → *
  • Actions → All Actions (*)
  • Amazon Resource Number (ARN) → Copy “arn” from permissions tab
  • Click “Add Statement”
Click Generate Policy

Clicking on “Generate Policy” will spit out the policy. You’ll need to edit the “Resource” section before copying it in the Permissions Tab.

“Resource”: [

AWS CodePipeline

Okay !! So we’re almost there. CodePipeline has different phases in which it can pull data, build, test and deploy code to the desired location. Our pipeline will be pretty simple with only two phases.

  • Source: Get latest commit from Github.
  • Build: Build the project and upload it to S3.

In the AWS Console, search for CodePipeline and click on the orange button labeled “Create Pipeline”.

Follow the steps below

1) Create a new pipeline
  • Enter Pipeline Name
  • Service Role → AWS will create a new service role or you can choose an existing one.
  • Artifact Store → Select custom location and choose the S3 bucket you created earlier.
2) Add Source
  • Source Provider → Select Github and login with your account.
  • Repository & Branch → Select appropriate repo and branch.
3) Create & Add Build Stage
  • Build Provider → Select AWS CodeBuild
  • Click on Create Project

AWS CodeBuild

4(a) Project Configuration
4(b) Build Environment Configuration
  • Environment Image → Managed Image
  • Operating System → Ubuntu
  • Runtine → Node.js
  • Runtime Version → Node.js:<latest-version>
  • Service Role → AWS will create a new service role or you can choose an existing one.
4(c) Add Environment Variables

Click on “Additional Configuration” to open the drop. At the bottom, add two env variables. We’ll use these variables in the buildspec.yml mentioned below.

  • ENVIRONMENT → dev | stage | prod
  • S3_BUCKET → s3://bucket-name
4(d) Buildspec
  • Select “Use a buildspec file”, this will make CodeBuild use the buildspec.yml file I mentioned earlier. Remember CodeBuild uses this file to specify which commands it should follow during, after and before the build process.

We use four phases in the buildspec.yml file. Each phase has a number of commands. All command and phases are executed in the order they are written in.

  • install → install npm, pip and awscli
  • pre-build → run “npm install”
  • build → build the react/vue project with “npm run build:$ENVIRONMENT”.
  • post-build → upload the “build/” folder to s3 bucket defined in the environmental variable $S3_BUCKET
Note: This way you can use the same “buildspec.yml” file with different CodeBuild projects, all with the same configurations but with different env variables depending on your environments.

This completes the CodeBuild setup, click on “Continue to CodePipeline” and you’ll be redirected to the AWS CodePipeline form.

5) Deploy

We don’t need the deploy stage because the buildspec.yml file builds and uploads the code to S3 bucket itself. So we‘ll “Skip deploy stage” and create the pipeline.

6) End Result

The finished pipeline will look something like this. It has only two phases, the “Source” phase which is responsible for pulling data from GitHub. And the “Build” phase which is responsible for building and deploying the code to S3.

For managing multiple environments just create another CodeBuild project with the appropriate environmental variables and add it to the existing CodePipeline.

With this setup you can use the same code base and buildspec.yml for multiple environments without needing to login to the console every time you update your app 😃