- [Jeremy] Okay, welcome back. Before we go ahead and create a purpose built builder image for our front end, let's first demonstrate the basic approach to working with the S2I command to scaffold out a new sample builder project. This is just to demonstrate functionality, we won't actually use it going forward.

Okay, let's go to step 18 within our run book, and copy the first command. I'll then jump back into the terminal and execute it like so. Now, this command basically sets up and scaffolds a new directory structure within a folder called S2I XYZ builder, for our custom S2I container-based builder image. Let's now examine more closely the directory structure that has just been generated. I'll use the tree command like so.

As you can see, this is the conventional layout that the S2I command works with. The main files that we need to customize when building a custom S2I container-based builder image are the following: the docker file, the assemble file, and the run file. Let's examine the contents of each of these files, including the make file. As you can see, the make file simply encapsulates performing a docker build over the local docker file. Next, the docker file is really where a lot of your customization is played. Again, this will become clearer in the next demo where I'll reuse an existing S2I build project, already created and stored on Get Up. Moving on, the assemble script is used to perform the code injection when a build takes place.

The assemble script is mostly used to move files about during the build phase. Again, this will become clearer in the next demo. And, finally, the run script is used at run time to launch processes within the container, and will perform other arbitrary tasks when the container is started. Remembering that the builder image generates an output image, the assemble script gets some vote within the builder container, and the run script gets some vote in the output container.

Let's now run a quick make on this sample builder project to create the sample builder container image. I'll run the following command to run the make command from within the S2I XYZ builder directory. As expected, a docker build kicks off and uses the docker file to direct it's build. This is now completed successfully. Finally, we can examine the local docker images to see the newly built XYZ builder image, and, as expected, it is tagged with the tag XYZ builder latest.

Okay, that completes step 18, and a quickfire intro into how to use S2I to scaffold new builder projects. In the next demo, I'll take a closer look at the front end builder project which is already customized and ready to be used.