Amazon Elastic Container Registry (ECR) is a fully managed container registry that can store (Docker) container images, making it easy to pull, share, and deploy container images. This post will teach you how to create a private Amazon ECR and push Docker container images of a simple Node.js Hello World app with Express. Let’s get started!
Table of contents #
- What is Amazon ECR
- The Node.js Hello World app
- Create private Amazon ECR
- Build and push Node.js Docker image
- Conclusion
What is Amazon ECR #
Amazon Elastic Container Registry (ECR) is an Amazon Web Service (AWS) service that stores and manages Docker images, making it easy to pull and deploy them to services like Elastic Container Service (ECS), Elastic Kubernetes Service (EKS), and/or AWS Lambda functions. Below is a quick overview of how it works from the official website.
Amazon ECR also has commands in the AWS CLI to do everything you can from the user interface. For this post, you will use the user interface to build and push a Docker image for a simple Node.js Express Hello World app.
The Node.js Hello World app #
It is assumed that you have Node.js 20+ installed on your local machine. If not, you can clone this repository in your AWS CloudShell. AWS CloudShell has Node 20 installed by default.
The Node.js Hello World app used for this tutorial is an Express 5.x app. You can start a Node.js app with npm init, and to install Express 5.x, you can run npm install express@next. Then, in the folder that has the package.json and package-lock.json, you can create an index.js file with the following code:
const express = require('express');
const app = express();
const port = process.env.PORT || 80;
app.get('/', (req, res) => {
res.send('Hello World!');
});
app.listen(port, () => {
console.log(`Example app listening on port ${port}`);
});It is a simple Node.js app with only one route / that prints Hello World using Express. If you run node index.js , you will see the following:
> node index.js
Example app listening on port 80After that, if you hit http://localhost on your favorite browser, you will see the text Hello World on the browser tab.
The next important file in the repository is the Dockerfile with the following content:
#buld stage
FROM public.ecr.aws/docker/library/node:22 AS build
WORKDIR /srv
COPY package*.json ./
# Install dependencies based on the `package.json` and `package-lock.json`
# files in the host folder
RUN npm ci --omit=dev
# Production stage, only includes what is needed for production
FROM public.ecr.aws/docker/library/node:22-alpine
ENV NODE_ENV=production
USER node
COPY --from=build /srv .
ADD . .
# Specify the command to run when launching the container
EXPOSE 80
CMD ["node", "index.js"]It is a Dockerfile using Docker multi-stage build to create the build and the production stage.
The easiest way to get started is to clone this repository in your AWS Cloud Shell and build the image there. Before that, you will first create the private Amazon ECR.
Create private Amazon ECR #
Amazon Elastic Container Registry (ECR) can be public or private. For example, this Node.js docker image is being served from the public ECR. No authentication is required to pull the node image. Conversely, the apps you develop will to be accessible to the public, so they are in a private ECR, which has some form of access control to ensure only the right users have access to it.
To create a private Amazon Elastic Container Registry (ECR), you must be logged into your AWS account and have the correct IAM permissions. This post does not cover the IAM permissions. In your AWS console, search for ecr as shown below:
Then click on Elastic Container Registry which will take you to the following page:
On this page, click on the Create yellow button, which will take you to the form below:
On the form, fill in the repository name as nodejs/hello-world, where nodejs is the namespace and hello-world is the app name.
It is better to keep the tags immutable so they are not overwritten. To do this, click the Immutable radio button in the Image tag mutability section. After that, keep the Encryption settings as is and click the Create button at the bottom of this page.
It might take some seconds for the EC registry to be created, and you will be taken to the Private repositories listing page as seen below:
In the next part, you will learn how to build and push a Docker container image using AWS Cloudshell. You are using AWS Cloudshell, so there is nothing to install on your machine. You can also do the same using your machine.
Build and push Node.js Docker image #
To build and push the Node.js Hello World (with Express.js) Docker image, you must first go to the repository by clicking its name, as seen in the previous screenshot.
You will land on the Images page of the repository, which will look like the below:
Before doing anything else, please click the CloudShell link at the bottom left side of the page. It will provision and run a shell for you:
Type in the following command in the shell:
mkdir projects && cd projects && git clone https://github.com/geshan/nodejs-aws-ecs-fargate.git && cd nodejs-aws-ecs-fargateThe above command creates a folder called projects and then goes into it. After that, it clones the above Node.js (Express) Hello World App, which also has the abovementioned Dockerfile. Subsequently, the last command takes you into the nodejs-aws-ecs-fargate folder.
It will result in the following state:
After that, click on the View push commands button on the left side of the page it will show a pop-up as seen below:
Copy all four visible commands and paste them into Notepad or your IDE. The commands I got were:
aws ecr get-login-password --region us-east-1 | docker login --username AWS --password-stdin <long-id-here>.dkr.ecr.us-east-1.amazonaws.com
docker build -t nodejs/hello-world .
docker tag nodejs/hello-world:latest <long-id-here>.dkr.ecr.us-east-1.amazonaws.com/nodejs/hello-world:latest
docker push <long-id-here>.dkr.ecr.us-east-1.amazonaws.com/nodejs/hello-world:latestThen, run them individually on your console, maintaining the order. After the first command, you will see Login Succeeded. That command is used to log in to the Elastic container registry.
The docker build command will take up to 5 minutes, wait for it. After the build is done, it will look something like the below:
The third command tags the built container with nodejs/hello-world:latest, which results in nothing. The fourth command pushes the image to the private Amazon ECR. If everything goes well, when it finishes, it will look like the following:
After that, close the cloud shell and refresh the Images page of the private Amazon ECR. You will see the pushed Docker image in the registry as follows:
You can see the image’s details by clicking the latest link, which will show you:
You can deploy the image's URL as a container in ECS, EKS, or even a Lambda function. The next part of this blog post series you will deploy the built and pushed container to Amazon Elastic Container Service (ECS).
Conclusion #
In this post, you learned about Amazon Elastic Container Registry (ECR), a service in Amazon Web Services (AWS). Then, you built a simple Hello World Node.js app with Express 5.x. After that, using the AWS interface, you created a private AWS ECR Docker image registry. Consequently, look at the command provided. You used AWS CodeShell to build and push the Hello World Node.js app image after cloning the repository from GitHub.
I hope you learned the basics of Amazon ECR, in the next part, you will deploy the container on Amazon Elastic Container Service (ECS) using Fargate for serverless resource provisioning. Keep learing!