notepadApp

Notepad application running on Azure

Setup

Please go through the following steps:

1. follow the instructions in terraform/README.md to setup your Kubernetes cluster in Azure;
2. then go through aks/README.md to setup the container registry in Azure and the application namespace in the cluster;
3. lastly you need to trigger the pipeline with GitHub Actions to build and deploy the application on the cluster.

Open issues

Failed deployment

Unfortunately the deployment fails for timeout; the deployed pods' logs contain:

/bin/sh: 1: ./bin/www: Permission denied

Database

The SQLite database is in the pods and it is created empty at every deployment. It should be either in a shared persistent storage claim in the cluster or in a external server; the latter option would require to change the application to let it use MySQL, PostgreSQL or MsSQL Server instead of SQLite.

Ingress and DNS

An ingress is deployed on the cluster, but it uses a dummy host name (notepad-app.example.com): no DNS has been set up. Neither ingress-nginx nor cert-manager are installed in the cluster: they could be installed with Helm.

Business requirements

Here are listed the business requirements of the assignment, and for each of them a comment about the application's compliance to them:

• The Application must serve variable amount of traffic. Most users are active during business hours. During big events and conferences the traffic could be 4 times more than typical.
  • The Horizontal Pod Autoscaler should be set up for the application's Kubernetes deployment in order to adapt the amount of pods to the traffic on the application.
• The Customer takes guarantee to preserve your notes up to 3 years and recover it if needed.
  • As previously mentioned the application should be changed to support an external SQL database.
• The Customer ensures continuity in service in case of datacenter failures.
  • The Kubernetes cluster should be able to maintain a costant amout of nodes, so in case one fails, a newer one will be spawned; an external SQL database with regular backups would definitely help.
• The Service must be capable of being migrated to any regions supported by the cloud provider in case of emergency.
  • The provided instructions give the possibility to recreate the same infrastructure within a short period of time.
• The Customer is planning to have more than 100 developers to work in this project who want to roll out multiple deployments a day without interruption / downtime.
  • The GitHub Actions pipeline can be triggered by that amount of developers and having more than one replica in the Kubernetes deployment avoids downtime to the application.
• The Customer wants to provision separated environments to support their development process for development, testing, production in the near future.
  • Different Kubernetes namespaces can be defined for different environments; ideally the production environment's namespace is located on a separate Kubernetes cluster.
• The Customer wants to see relevant metrics and logs from the infrastructure for quality assurance and security purposes.
  • The Log Analytics Workspace created in Azure with Terraform together with the Kubernetes cluster can be used in order to get metrics and logs from the cluster.