1. Deploying a Docker Container on AWS EC2 from Scratch

This guide will walk you through the steps to deploy your Docker container on an AWS EC2 instance.

Prerequisites

  • AWS Account
  • Docker installed on your local machine
  • An application to deploy (Dockerized)

1. Build Your Application

First, create and test your application locally. Once the app is ready, move to the next steps to containerize it using Docker.

2. Create a Docker Image

Once your app is built, you need to create a Docker image for it, for example: docker-user/image-name:tag

sudo docker build -t miguelzeph/flask-news:latest .

2.1 Option A: Create a .tar Image for SSH Transfer

If you plan to transfer the image to your EC2 instance via SSH, create a tarball (.tar) of your Docker image by running:

docker save -o <image-name>.tar <image-name>

2.2 Option B: Push to Docker Hub

Alternatively, you can push your image to Docker Hub:

  • 1.Login:
sudo docker login
  • 2.Push your image:
docker push <dockerhub-username>/<repository>:<tag>
# ex: docker push miguelzeph/flask-news:latest

Once your image is on Docker Hub, you can pull it from the EC2 instance later.

3. Launch an EC2 Instance

  • Go to the AWS Management Console and create an EC2 instance.
  • Choose the appropriate AMI (Amazon Machine Image) and instance type (e.g., t2.micro).

3.1 Modify Storage Volume (Optional)

Increase the default storage volume size up to 30GB — this is covered under the free tier.

3.2 Save the SSH Key

During instance creation, generate and download a key pair (.pem file). You'll need this to SSH into your instance.

3.3 Access the EC2 Instance

Once the EC2 instance is running, you can access it in two ways:

  • SSH into the EC2 Instance If you are accessing from your terminal, use SSH with the .pem key to connect:
ssh -i your-key.pem ec2-user@your-ec2-public-ip

Or You can also connect directly through the AWS Console:

  • connect via AWS Console (easier)
    • In the EC2 Dashboard, find your instance.
    • Click Connect.
    • Choose the EC2 Instance Connect tab and click Connect.

3.3 Install Docker on EC2

Once the instance is running, SSH into (or access from AWS console clicking in "Connect") the EC2 instance and install Docker.

3.4 Load the Docker Image on EC2

Now, you can either:

  • Option A: Copy the .tar file using scp
scp -i <your-key>.pem <image-name>.tar ubuntu@<ec2-public-ip>:~/

Then load the image:

docker load -i <image-name>.tar
  • Option B: Pull the image directly from Docker Hub:
docker login
docker pull <dockerhub-username>/<repository>:<tag>

3.5 Run the Container

  • Run your Docker container on the EC2 instance:
docker run -d -p <host-port>:<container-port> <image-name>

# Example
sudo docker run -d -p 8000:8000 miguelzeph/flask-news:latest gunicorn -w 4 -b 0.0.0.0:8000 app:app
  • P.S -> In case you have chosen the B process (using DockerHub), create a file to configure your own app (because the conf file used to create the image was just an example to not push sensitive information to the repository).
# Create a file for your configuration according to your project
nano config_flask_news.yml
  • Copy this file to the Container that is running with the application (get the container-id using ps command).
sudo docker cp config_flask_news.yml <container-id>:/app/config_example.yml
  • Restart the Container if necessary
sudo docker stop <container-id>
sudo docker start <container-id>

4. Configure EC2 Security Group

Create or modify a security group for your EC2 instance to allow incoming traffic on the ports needed by your application (e.g., HTTP: 80 or a custom port).

  • Go to the EC2 Dashboard > Security Groups.
  • Select the security group associated with your EC2 instance.
  • Click Edit Inbound Rules and add the following rules
    • SSH (to allow SSH access): bash Type: SSH Protocol: TCP Port Range: 22 Source: 0.0.0.0/0
    • Custom TCP Rule (to allow access to your application) for the necessary ports and set the source to 0.0.0.0/0 or restrict it to specific IPs: bash Type: Custom TCP Rule Protocol: TCP Port Range: <your-app-port> Source: 0.0.0.0/0

Make sure the port you're exposing is open and accessible from external sources. This will allow you to access both your application and SSH into your EC2 instance.

5. Assign an Elastic IP

To ensure your public IP remains static (doesn’t change when you stop/start your instance):

  1. Navigate to Elastic IPs in the EC2 Console.
  2. Allocate a new Elastic IP.
  3. Associate the Elastic IP with your running EC2 instance.

Note: Some cloud databases (like AWS RDS) require you to whitelist this static IP so that your application can access the database.

6. Test Your Application

Make sure the necessary ports are open in the security group, and access your application in the browser:

http://<your-static-ip>:<host-port>