Managing an Application from GitHub

In the first half of this workshop, we packaged an application into this portable container format manually using rpms. In the second half, we will consider that you may want to manage software from GitHub or some kind of software versioning application. Rather than installing rpms, we have individual software files and pull them out of that version control into a group of systems.

Install RHEL 8 UBI

In this lab, we will be using a different Red Hat Enterprise Linux version in my container.

Verify the host system release

cat /etc/redhat-release

The bastion system is Red Hat Enterprise Linux 9, and when you built the previous container, you used the UBI9 image. This means both the image and the container were built off the same Red Hat Enterprise Linux packages.

As we did previously in this lab, Use buildah from to pull down the Red Hat Enterprise Linux 8 UBI.
```
buildah from registry.access.redhat.com/ubi8/ubi
```

Because you already pulled one image named ubi-working-container this one is called ubi-working-container-1.

Install Prerequisites

Now that you have a working container, you will use the same process as before installing all the prerequisites, changing config files, and manipulating the contents of this container to be in the desired state.

The software you will install is a JavaScript-based game that runs on a web browser. As before in the lab, use dnf to install software inside the container.

Use buildah run and install Apache (httpd) into the ubi-working-container-1 container.
```
buildah run ubi-working-container-1 -- dnf -y install httpd
```

Enable Service

The next thing to do is to use a systemctl to enable the service. The ubi-init provides full systemd service to the container. This will start up any of the services that are enabled.

Enable the httpd service using buildah run

buildah run ubi-working-container-1 -- systemctl enable httpd

The UBI standard image doesn’t have systemd installed on it by default. The ubi-init container image does include systemd. Plan accordingly to which image you use to build applications.

Explore Source Materials

A GitHub repository has already been synchronized to /home/devops/clumsy-bird/ This repository contains the configurations for your application.

Verify the repository is cloned inside the /home/devops/ directory
```
cd /home/devops/
```
```
git clone https://github.com/ellisonleao/clumsy-bird
```
The output states that the software has already been checked out.
Explore the JavaScript contents, index files, and everything else that we need for this web-based JavaScript software.
```
ls clumsy-bird
```

Add Source Materials to Container

Now that you have verified the source materials exist, you will put the software inside of my container image using the buildah copy command.
```
buildah copy ubi-working-container-1 clumsy-bird /var/www/html
```

Enable Container in Background

In the previous section of this lab, you ran the game natively through interactive mode. Because you are now building a web application you will need to run the container in the background and access it through a web address.

Execute buildah config to specify a port and initialize the container.

buildah config --port 80 --cmd "/usr/sbin/init" ubi-working-container-1

The command makes a configuration change to this container. I’m configuring this container to accept connections to its port 80. When the container starts up, it should run the init command, which, in this case, is going to be the Apache daemon right from earlier when I enabled it.

Commit Container and Deploy

Now that we have a container in a working configured state, it is time to make that permanent by committing it to a container image called clumsy-bird
```
buildah commit ubi-working-container-1 clumsy-bird
```
Verify that the image was created with podman
```
podman images
```
Run the container Now it’s time to run the container.
```
podman run -d -p 8500:80 clumsy-bird
```

Verify Application

Verify that the application is running by navigating to

http://bastion.my-guid.example.opentlc.com:8500