Node PostgreSQL DevContainer Example

This repository is part of a presentation about DevContainers. Please check this repository as a starting point.

What you will learn

How to setup a dev environment with:

• Node.Js
• Terraform - IaC
• LocalStack - AWS local environment
• Act - Github Actions local environment

You will be able to test from application to ci/cd.

Repo structure

├── .devcontainer.backup -> If you follow the tutorial, but it's not working you can use this working devcontainer to
├── .github -> It contains the GitHub action that deploys this project
├── terraform -> It uses terraform to provision resource on AWS
├── src -> It contains a testing code written in node.js
└── scripts -> It contains useful scripts 

Setting up the devcontainer

Ensure you have Docker, VSCode, and Dev Containers extension installed.

Open the command palette and click Add Dev Container Configuration Files. This will start a wizard to create your devcontainer.json file.

Select add configuration to workspace. This will create the devcontainer.json inside your project allowing you to commit and share with others.

Now you need to choose the base image that your container will run. Here we will select Ubuntu.

Choose the Ubuntu version that you want to use. Here we will keep the default one.

Now it's time to configure the features that we want to have installed in our container. This sample uses the following features:

• AWS CLI
• Terraform (via asdf)
• Docker (Docker-outside-of-docker)
• Localstack
• Node.js (via asdf)
• Python
• Act (via asdf)

Now you can configure the features. As this sample does not require any changes you can click on Keep Defaults

Done! Now you should have a .devcontainer folder in your project.

Before running our container, we need to make some changes.

First, we will forward a port that is used by Localstack, this will ensure that you can connect the Localstack Desktop app to the container. To do this add the following line to the devcontainer.json

// Use 'forwardPorts' to make a list of ports inside the container available locally.
"forwardPorts": [4566],

We also want to customize our vscode environment by adding extensions and defining bash as the default shell. You can do this customization by adding the following lines to the devcontainer.json

// Configure tool-specific properties.
"customizations": {
 "extensions": [
 "ms-vscode-remote.remote-containers"
 ],
 "vscode": {
 "settings": {
 "terminal.integrated.shell.linux": "/bin/bash",
 },
 "extensions": [
 "hashicorp.terraform",
 "4ops.terraform",
 "dbaeumer.vscode-eslint"
 ]
 }
},

The last change we need to do is configure the container to run a custom script after the container is created. You can do this by adding the following lines to the devcontainer.json

// Use 'postCreateCommand' to run commands after creating the container.
"postCreateCommand": "bash scripts/postCreateCommand.sh",

This script, which you can find in script folder, will make sure that the Localstack is clean, the aws is configured and the project is ready to be executed

So every time that the container is created it will run this script finishing the container preparation.

Now you can start your container. You can open the Command Palette and click on Reopen in Container

After a few moments, your container will be available and ready to use.

Using this container

Running your application locally

To run this application you can run node main.js on the src folder.

You can also debug normally by pressing F5 on the main.js file.

Running your CI/CD locally

You can test your entire CI/CD locally using the Act tool. This tool executes a Github Action locally. This repository contains a workflow that can be executed by running the following command.

• act -j test - run the job with the name test
• act - run the the entire pipeline
• act -l - view the execution graph

In the first execution, you will need to define the image that will be used. I recommend using the Medium.

On this project, we have a sample workflow that deploys the infrastructure using Terraform, builds the app, and runs the lint and tests.

Accessing the local AWS

You can check the AWS local resources using the AWS CLI or download the LocalStack Desktop. Localstack has a community license that allows you to simulate some AWS resources but for some resources, you will need a pro license.