A Dockerized RESTful API implemented using Flask containing a counter which increments everytime the API endpoint is hit. The count persists in a MySQL database mounted to a persistent volume, hence surviving pod restarts. The webservice and database are deployable in K8s and the manifests are included in the project directory.
The webservice and database are deployable in K8s. These were tested on a local
minikube cluster - this section will deal with deploying onto such a cluster, and can be
used as a template for deploying onto any cluster.
The MySQL root user password is defined in secrets.yml and defaulted to
p@ssw0rd1. To define a new password, change the db_root_password
field in secrets.yml (make sure your new password is Base64-encoded) and the password parameter of the mysql.connector.connect()
calls in app.py (which is not encoded).
The mysql-deployment.yml manifest utilizes the default
mysql image, so this should be pulled with $ docker pull mysql.
Build the image of the API with $ docker build --tag opsviewapi-1 .
in the project directory.
Deploy the API and database with
$ kubectl apply -f mysql-deployment.yml,opsviewapi.yml,persistent-volume.yml,secrets.yml.
If on Minikube, access the service itself by running
$ minikube service opsviewapi-service
and accessing the returned endpoint. After recieving message app run successfully, hit enpoint
http://<URL>/initdb to initialize the database, and then hit endpoint
http://<URL>/counter to increment the counter, as desired.
Copyright © Alon Lavie 2022