This repository contains the code for the Twitter feed microservice. It was slightly changed from the original to enable you to configure a CI/CD pipeline using GitLab (Self-managed or Gitlab.com), and deploy the microservice to Oracle Cloud Infrastructure - Container Service for Kubernetes (OKE).

GitLab is a very popular web-based DevOps lifecycle tool that provides a git-repository manager, CI/CD and many other features and is available in Community Edition (Open source) or Enterprise Edition (License required).

In order to complete the workshop and deploy the microservice you need to have access to:

• Oracle Cloud Infrastructure account with OKE cluster deployed
• Oracle Cloud Infrastructure User Authentication Token
• Oracle Cloud Infrastructure Container Registry (OCIR) access
• GitLab (self-managed, e.g deployed on OCI or sign up for a gitlab.com account)
• GitLab Runners with Kubernetes and/or Docker executors (available as shared runners on gitlab.com and/or you can also provision your own on OCI)
• Docker (for local tests only)

GitLab allow you to Import a project from any git repository at the time you create your project. In order to create a new Project for the twitter-feed-oke application, follow these steps:

1. Click on New Project button -> Import project -> Import Project from Repo by URL
2. Enter Git repository URL: https://github.com/gilsonmelo/twitter-feed-oke.git

To integrate your CI/CD pipeline with all your infrastructure, you need to prepare your environment and gather some information that should be stored in your project as CI/CD Variables. GitLab allow you to define variables to store individual values (e.g. Strings) or files like SSH keys. These variables can be accessed directly from your pipelines.

As part of the CI/CD Pipeline, we are going to publish a Docker Image into the OCIR repository. Oracle Cloud Infrastructure Container Registry (OCIR) is an Oracle-managed registry that enables you to store, share, and manage development artifacts like Docker images. You can create a public or private registry and then use the Docker V2 API and/or Docker CLI for pushing and pulling Docker images. You can check the requirements for creating the registry on the OCI Registry documentation.

To publish a Docker image to OCI Registry using Docker CLI we need a valid user and an Auth token to authenticate the user. You can store that token and other information on GitLab as variables.

Notes:

1. If you don't have a repository in the OCI Container Registry, you can create one following the documentation or when you push the first Docker image through the CI/CD pipeline a new repository will be created automatically for you.
2. If you don't have an Auth Token, you can generate one following the documentation. Take notes on the token as it is not displayed twice.

Now you can go back to GitLab and create the variables used by your Project during the CI/CD pipeline.

1. Go to Settings > CI/CD -> Variables -> Expand
2. Click on Add Variable button and add the following variables: