Project Overview

This application simplies the access to the covid 19 stats of the world (stats for each country). This application is used to implement all the knowledge acquired on the Cloud DevOps Engineer Nano Degree on Udacity. The app has a simple api with two endpoints, the app is built it on top of Python using Flask and BeautifulSoup 4 (to scrape the data).

API URL: <your-api-url> (see the Verifying section to get the url of your api).

Endpoints	Path	Description
GET	/	Returns a Hello World! message with the current state of the app (blue or green).
GET	/world-stats	Returns covid stats of the world.

PROJECT STRUCTURE

File Name	Description
├── code/	This directory contains the Python Flask app and Tests
├── capstone/	Python Flask App.
├── tests/	Tests for the Python Flask App.
├── .coveragerc	Python Coverage configuration file.
├── requirements-ci.txt	Python dependencies file for Continuous Integration (CI).
├── requirements-dev.txt	Python dependencies file for development.
├── requirements.txt	Python dependencies file for production.
├── run.py	Python script to run the application.
└── tox.ini	Flask8 configuration file.
├── infra/	This directory contains the files for docker and kubernetes.
├── docker/	Docker files for blue and green images.
├── k8s/	Kubernetes files for blue and green deployments.
└── server.yaml	Template to create the cluster on Amazon EKS using EKSCTL.
├── nginx/	This directory contains the files for a custom NGINX configuration.
├── screenshots/	This directory contains the screenshots for the project validation.
├── .editorconfig	Configuration file for editorconfig.
├── .gitignore	Configuration file for gitignore.
├── Jenkinsfile	Configuration file for Jenkins Pipelines.
├── Makefile	Set of custom scripts.
├── README.md	Description of the app.
└── TODO.md	Project TODO.

Pre-requisites

• AWS CLI: https://docs.aws.amazon.com/cli/latest/userguide/cli-chap-install.html
• AWS IAM Roles for EKS: https://docs.aws.amazon.com/eks/latest/userguide/security_iam_service-with-iam.html
• Jenkins: https://www.jenkins.io/download/
• Docker: https://docs.docker.com/engine/install/
• Kubernetes: https://kubernetes.io/es/docs/tasks/tools/install-kubectl/
• EKSCTL: https://eksctl.io/introduction/#installation

Note: Jenkins needs Java to run. To install Java for jenkins run this command: sudo apt install default-jdk -y (only Debian distros)

Setup

1. Create the Cluster

To create a cluster you can use the following command.

$ eksctl create cluster -f ./infra/eks/cluster.yaml

Note: You can create the cluster manually following this guide: https://docs.aws.amazon.com/eks/latest/userguide/create-cluster.html

2. Create a Kubernetes config for Amazon EKS

To create/update a Kubernetes config (kubeconfig) you can use following command.

$ aws eks --region us-east-1 update-kubeconfig --name capstone-cluster

Note: Read more about kubeconfig files for EKS on: https://docs.aws.amazon.com/eks/latest/userguide/create-kubeconfig.html

3. Configure Jenkins

Plugins

• AWS Pipeline: https://plugins.jenkins.io/pipeline-aws
• Aqua MicroScanner: https://plugins.jenkins.io/aqua-microscanner/
• BlueOcean: https://plugins.jenkins.io/blueocean/, https://plugins.jenkins.io/blueocean-executor-info/

Credentials

• Docker (Steps):
  • ➡️ Jenkins (Dashboard)
  • ➡️ Manage Jenkins
  • ➡️ Configure System
  • ➡️ Declarative Pipeline (Docker)
• Kubernetes Config File (Steps):
  • ➡️ Jenkins (Dashboard)
  • ➡️ Job (github repo)
  • ➡️ Credentials
  • ➡️ Store scoped to <github-repo>
  • ➡️ Global
  • ➡️ Add credentials
    • Kind: Secret Text
    • ID: k8s-confige-file
    • Secret: /path/to/your/kubeconfig-file (absolute paths) e.g: /home/ubuntu/.kube/kubeconfig
• AWS (Steps):
  • ➡️ Jenkins (Dashboard)
  • ➡️ Job (github repo)
  • ➡️ Credentials
  • ➡️ Store scoped to <github-repo>
  • ➡️ Global
  • ➡️ Add credentials
    • Kind: AWS Credentials
    • ID: aws-creds
    • Fill the other fields.

Pipelines

To create a pipeline using BlueOcean follow this guide: https://www.jenkins.io/doc/book/blueocean/creating-pipelines/

Deploying

Automate deploys

You can trigger the deployments just pushing update the right branch. If you want to a blue deployment push your changes to the blue branch.

Manual deploys

You can trigger manual deploy using the following command:

$ kubectl apply -f ./infra/k8s/deployments/blue.yaml
$ kubectl apply -f ./infra/k8s/services/blue.yaml

or

$ kubectl apply -f ./infra/k8s/deployments/blue.yaml -f ./infra/k8s/services/blue.yaml

Note: This step require to access to your ec2 instance before. Check the Verifying section to get help.

Verifying

1. Connect to the EC2 instance using ssh

To connect to your EC2 instance follow this guide: https://docs.aws.amazon.com/quickstarts/latest/vmlaunch/step-2-connect-to-instance.html

2. Get the link to the appplication

To get the external ip of our service you can use the following command:

$ kubectl get services -l app=capstone --output jsonpath='{.items[].status.loadBalancer.ingress[].hostname}'

With the link you can access to the app. If all is working yo can see a message like this:

{"message":"Hello GREEN APP!"}

or

{"message":"Hello BLUE APP!"}

Thanks to

A big thanks to

• Udacity
• Raul Hugo @RaulHugo