Build a Custom Image

Now that we can run Hello World, we need to customize the web server response.

This customization poses a challenge.

First, we need a way to specify in code our new layer of customization. Next, we need place to push any new custom data. Finally we need a way to pull the custom data to run it as a Container.

So we need build configuration and a Registry Service.

We can specify our build configuration by adding a Dockerfile that adds a Layer on top of the pre-built Apache httpd Image.

FROM httpd
COPY ./public-html/ /usr/local/apache2/htdocs/

web:
  build: .
  ports:
    - 80:80

 ┌────────────────┐ 
┌┤       LB       ├┐
│└────────────────┘│
│┌───────┐┌───────┐│
││┏━━━━━┓││┏━━━━━┓││
││┃web 1┃││┃web 2┃││
││┗━━━━━┛││┗━━━━━┛││
││ VM 1  ││ VM 2  ││
│└───────┘└───────┘│
│       VPC        │
└──────────────────┘
┌────────┐          
│Registry│          
└────────┘          

The Registry will provide an API and persistance for pushing and pulling custom layers of data like our new public-html directory.

A Build System will push layers to the Registry and the Container Service will pull layers when starting new Cotnainers.