Creating a container image for use on Amazon ECS

Create a file called Dockerfile. A Dockerfile is a manifest that describes the base image to use for your Docker image and what you want installed and running on it. For more information about Dockerfiles, go to the Dockerfile Reference.

touch Dockerfile

Edit the Dockerfile you just created and add the following content.

FROM public.ecr.aws/amazonlinux/amazonlinux:latest

# Update installed packages and install Apache
RUN yum update -y && \
 yum install -y httpd

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

# Configure Apache
RUN echo 'mkdir -p /var/run/httpd' >> /root/run_apache.sh && \
 echo 'mkdir -p /var/lock/httpd' >> /root/run_apache.sh && \
 echo '/usr/sbin/httpd -D FOREGROUND' >> /root/run_apache.sh && \
 chmod 755 /root/run_apache.sh

EXPOSE 80

CMD /root/run_apache.sh

This Dockerfile uses the public Amazon Linux 2 image hosted on Amazon ECR Public. The RUN instructions update the package caches, installs some software packages for the web server, and then write the "Hello World!" content to the web servers document root. The EXPOSE instruction means that port 80 on the container is the one that is listening, and the CMD instruction starts the web server.

Build the Docker image from your Dockerfile.

docker build -t hello-world .

List your container image.

docker images --filter reference=hello-world

Output:

REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
hello-world         latest              e9ffedc8c286        4 minutes ago       194MB

Run the newly built image. The -p 80:80 option maps the exposed port 80 on the container to port 80 on the host system.

docker run -t -i -p 80:80 hello-world

Open a browser and point to the server that is running Docker and hosting your container.

You should see a web page with your "Hello World!" statement.

Stop the Docker container by typing Ctrl + c.

Create an Amazon ECR repository to store your hello-world image. Note the repositoryUri in the output.

Substitute region, with your AWS Region, for example, us-east-1.

aws ecr create-repository --repository-name hello-repository --region region

Output:

{
    "repository": {
        "registryId": "aws_account_id",
        "repositoryName": "hello-repository",
        "repositoryArn": "arn:aws:ecr:region:aws_account_id:repository/hello-repository",
        "createdAt": 1505337806.0,
        "repositoryUri": "aws_account_id.dkr.ecr.region.amazonaws.com/hello-repository"
    }
}

Tag the hello-world image with the repositoryUri value from the previous step.

docker tag hello-world aws_account_id.dkr.ecr.region.amazonaws.com/hello-repository

Run the aws ecr get-login-password command. Specify the registry URI you want to authenticate to. For more information, see Registry Authentication in the Amazon Elastic Container Registry User Guide.

aws ecr get-login-password --region region | docker login --username AWS --password-stdin aws_account_id.dkr.ecr.region.amazonaws.com

Output:

Login Succeeded

Push the image to Amazon ECR with the repositoryUri value from the earlier step.

docker push aws_account_id.dkr.ecr.region.amazonaws.com/hello-repository