Creating container images for your Amazon Lightsail container services

Last updated: November 12, 2020

Docker is the technology that allows you to build, run, test, and deploy distributed applications that are based on containers. Amazon Lightsail container services use Docker container images in deployments to launch containers.

In this guide, we show you how to create a container image on your local machine using a Dockerfile. After your image is created, you can then push it to your Lightsail container service to deploy it.

To complete the procedures in this guide you should possess a basic understanding of what Docker is and how it works. For more information about Docker, see What is Docker? and the Docker overview.

Contents

Step 1: Complete the prerequisites
Step 2: Create a Dockerfile and build a container image
Step 3: Run your new container image
(Optional) Step 4: Clean up the containers running on your local machine
Next steps after creating container images
Additional information about container services

Step 1: Complete the prerequisites

Before you get started, you must install the software required to create containers and then push them to your Lightsail container service. For example, you must install and use Docker to create and build your container images that you can then use with your Lightsail container service. For more information, see Installing software to manage container images for your Amazon Lightsail container services.

Step 2: Create a Dockerfile and build a container image

Complete the following procedure to create a Dockerfile, and build a mystaticwebsite Docker container image from it. The container image will be for a simple static website hosted on an Apache webserver on Ubuntu.

Create a mystaticwebsite folder on your local machine where you will store your Dockerfile.
Create a Dockerfile in the folder you just created.
The Dockerfile does not use a file extension, such as .TXT. The full file name is Dockerfile.
Copy one of the following code blocks depending on how you want to configure your container image, and paste it into your Dockerfile:
- If you want to create a simple static website container image with a Hello World message, then copy the following code block and paste it into your Dockerfile. This code sample uses the Ubuntu 18.04 image. The RUN instructions updates the package caches, and installs and configures Apache, and prints a Hello World message to the web server's document root. The EXPOSE instruction exposes port 80 on the container, and the CMD instruction starts the web server.
```
FROM ubuntu:18.04

# Install dependencies
RUN apt-get update && \
 apt-get -y install apache2

# Write hello world message
RUN echo 'Hello World!' > /var/www/html/index.html

# Open port 80
EXPOSE 80

# Start Apache service
CMD ["/usr/sbin/apache2ctl", "-D", "FOREGROUND"]
```
- If you want to use your own set of HTML files for your static website container image, create an html folder in the same folder where you store your Dockerfile. Then put your HTML files in that folder.
  After your HTML files are in the html folder, copy the following code block and paste into to your Dockerfile. This code sample uses the Ubuntu 18.04 image. The RUN instructions updates the package caches, and installs and configures Apache. The COPY instruction copies the contents of the html folder to the web server's document root. The EXPOSE instruction exposes port 80 on the container, and the CMD instruction starts the web server.
```
FROM ubuntu:18.04

# Install dependencies
RUN apt-get update && \
 apt-get -y install apache2

# Copy html directory files
COPY html /var/www/html/

# Open port 80
EXPOSE 80

CMD ["/usr/sbin/apache2ctl", "-D", "FOREGROUND"]
```
Open a command prompt or terminal window and change the directory to the folder in which you are storing your Dockerfile.
Enter the following command to build your container image using the Dockerfile in the folder. This command builds a new Docker container image named mystaticwebsite.
```
docker build -t mystaticwebsite .
```
You should see a message that confirms your image was successfully built.
Enter the following command to view the container images on your local machine.
```
docker images --filter reference=mystaticwebsite
```
You should see a result similar to the following example, showing the new container image created.
Your newly built container image is ready to be tested by using it to run a new container on your local machine. Continue to the next Step 3: Run your new container image section of this guide.

Step 3: Run your new container image

Complete the following steps to run the new container image you created.

In a command prompt or terminal window, enter the following command to run the container image that you built in the previous Step 2: Create a Dockerfile and build a container image section of this guide. The -p 8080:80 option maps the exposed port 80 on the container to port 8080 on your local machine. The -d option specifies that the container should run in detached mode.
```
docker container run -d -p 8080:80 --name mystaticwebsite mystaticwebsite:latest
```
Enter the following command to view your running containers.
```
docker container ls -a
```
You should see a result similar to the following example, showing the new running container.
To confirm that the container is up and running, open a new browser window and browse to http://localhost:8080. You should see a message similar to the following example. This confirms that your container is up and running on your local machine.
Your newly built container image is ready to be pushed to your Lightsail account so that you can deploy it to your Lightsail container service. For more information, see Pushing and managing container images on your Amazon Lightsail container services.

(Optional) Step 4: Clean up the containers running on your local machine

Now that you've created a container image that you can push to your Lightsail container service, it's time to clean up the containers that are running on your local machine as a result of following the procedures in this guide.

Complete the following steps to clean up the containers running on your local machine:

Run the following command to view the containers that are running on your local machine.
```
docker container ls -a
```
You should see a result similar to the following, which lists the names of the containers running on your local machine.
Run the following command to remove the running container that you created earlier in this guide. This forces the container to be stopped, and permanently deletes it.
```
docker container rm <ContainerName> --force
```
In the command, replace <ContainerName> with the name of the container you want to stop, and delete.
Example:
```
docker container rm mystaticwebsite --force
```
The container that was created as a result of this guide should now be deleted.

Next steps after creating container images

After you create your container images, push them to your Lightsail container service when you're ready to deploy them. For more information, see Pushing and managing container images on your Amazon Lightsail container services.

Additional information about container services

These are the general steps to manage your Lightsail container service after it's up and running:

Get familiar with all of the elements of Lightsail container services. For more information, see Container services in Amazon Lightsail.
Create your container service in your Lightsail account. For more information, see Creating Amazon Lightsail container services.
If you plan to use container images from a public registry, find container images from a public registry such as the Amazon ECR Public Gallery. For more information about Amazon ECR Public, see What Is Amazon Elastic Container Registry Public? in the Amazon ECR Public User Guide.
If you plan to push container images from your local machine to your service, install software on your local machine that you need to create your own container images and push them to your Lightsail container service. For more information, see the following guides:
Create a deployment in your container service that configures and launches your containers. For more information, see Creating and managing deployments for your Amazon Lightsail container services.
View previous deployments for your container service. You can create a new deployment using a previous deployment version. For more information, see Viewing and managing deployment versions of your Amazon Lightsail container services.
View the logs of containers on your container service. For more information, see Viewing the container logs of your Amazon Lightsail container services.
Create an SSL/TLS certificate for the domains that you want to use with your containers. For more information, see Creating SSL/TLS certificates for your Amazon Lightsail container services.
Validate the SSL/TLS certificate by adding records to the DNS of your domains. For more information, see Validating SSL/TLS certificates for your Amazon Lightsail container services.
Enable custom domains by attaching a valid SSL/TLS certificate to your container service. For more information, see Enabling and managing custom domains for your Amazon Lightsail container services.
Monitor the utilization metrics of your container service. For more information, see Viewing container service metrics in Amazon Lightsail.
(Optional) Scale the capacity of your container service vertically, by increasing its power specification, and horizontally, by increasing its scale specification. For more information, see Changing the capacity of your Amazon Lightsail container services.
Delete your container service if you're not using it to avoid incurring monthly charges. For more information, see Deleting Amazon Lightsail container services.