How to create a container image – Tilaa Support desk

In this example we will create a simple Docker container with a website running on NGINX.

Prerequisites:

Docker: You should have Docker installed on your machine. You can download and install it from the Docker website.

Online repository: You should have an account for an online container repository. In this example we're using Docker Hub.

Step 1: Write your application.

Before creating a container, you need an application to containerise. Write your application code and ensure it's functional. It's also a good practice to have a working directory with all necessary files, configurations, and dependencies.

In our case, this is our “to be containerized” website saved as index.html in a folder called My_Test_Website (~/ServerlessContainers/My_Test_Website/index.html):

HTML Copy

<!DOCTYPE html>
<html>
    <body>
        <h1>Docker test!</h1>
        <h1>It works on my machine...</h1>
        <p>Not sure if it'll work on yours?</p>
        <p>Try using containers!!</p>
    </body>
</html>

Step 2: Dockerize your application.

To run your application as a container, you need to create a Docker image.

First, create a ‘Dockerfile’ in the root of your application directory to define the image.

(~/ServerlessContainers/Dockerfile)

# Use the existing, official NGINX image as the base.
FROM nginx:latest
# Copy the website content into NGINX's default web directory.
COPY My_Test_Website /usr/share/nginx/html

Build the docker image:

Now that we've created the docker file, it's time to build the image using the 'docker build' command!

In this example we'll also be adding a tag.

DOCKER Copy

docker build -t serverlesscontainersdemo:1.0 .

Please note that the name here also needs to be the same as your registry (if you want to push it to your container registry). For example:

DOCKER Copy

docker build -t tilaa/serverlesscontainersdemo:1.0 .

After running this, you now have a container image!

Step 3: Test run your Docker Container.

Now that our image was created, let's start the container based on that image using the 'docker run' command.

DOCKER Copy

docker run -d -p 8080:80 serverlesscontainersdemo:1.0

In this example, the NGINX container's port 80 is exposed on port 8080 of your host machine.

To verify that the container is up and running, and to see the status, you can run the 'docker ps' command.

BASH Copy

docker ps
        CONTAINER ID   IMAGE                            COMMAND                     CREATED     STATUS    PORTS
        12abcd3e45fg   serverles containers demo:1.0    "/docker-entrypoint.…"      x seconds   Up x      0.0.0.0:8080->80/tcp

Open a web browser and navigate to http://localhost:8080 or use the appropriate URL if you specified a different port. You should see your simple website running on NGINX.

Step 4: Clean up.

To stop and remove the Docker container, use the following commands:

DOCKER Copy

docker stop container-id
docker rm container-id

Congratulations! You've created a container with a simple website running on NGINX.

Step 5: Upload to your online repository.

In order to upload your Docker image to our Serverless Containers platform, you'll need to use an online container registry.

In this example, we'll be using Docker Hub.

First, log in with your Docker Hub access token with read and write permissions:

docker login
username: demo
password: xxxxxxxxxxxxxx

Once you're logged in you can push your image to your repository.

docker push tilaa/serverlesscontainersdemo:1.0

This will upload the image to the account and repository of the same name.

For further information on Docker and the Docker Hub, check out Docker docs.

The next step

Is to upload the container to the Serverless Containers platform. To learn how to do this, check out the article here.