Solution for chart per service approach with Helm Charts in Openshift

• Preparation

• Helm chart setup for the microservice

  • Replicate the installation in qa project

• Validation and more

• Compatibility

• License

Use a Helm chart per microservice approach if you seek to achieve flexible, simple versioning and low complexity charts to package your application. Be careful, this technique might bring:

• huge amount of duplication

• difficulty to keep consistent many templates

• hardship to introduce global changes

Goal of this section: deploy the landmark microservice using Helm charts.

All the below commands will be executed in a terminal window.

Preparation

Assuming that you already cloned the landmark project, execute the following:

$ git checkout solution/chart-per-service-lab
$ git pull

To login to the OpenShift cluster from the Terminal run:

$ oc login -u kubeadmin -p YOUR_SECRET_PASSWORD https://api.crc.testing:6443

Check if you already have the dev project:

$ oc get project
$ oc new-project dev

The landmark microservice will persist its data into a database, in this case a PostgreSQL database instance.

In order to install the database, the PostgreSQL Helm Charts will be used. Check if the Helm repo https://charts.bitnami.com/bitnami is added to your existing list:

$ helm repo list

If the repo is not there, please run the following set of commands:

$ helm repo add bitnami https://charts.bitnami.com/bitnami

Setup the database instance with Helm, using the following command:

$ helm install landmark-db \
--set postgresqlUsername=landmark-default,postgresqlPassword=postgres,postgresqlDatabase=landmark,persistence.enabled=false \
stable/postgresql
$ helm status landmark-db

Validate the installation via:

$ helm list
$ helm get all landmark-db

Helm chart setup for the microservice

Install your charts in dev project

$ helm install simple ./chart/landmark
$ helm status simple
$ kubectl get ns
$ kubectl get svc
$ kubectl port-forward --namespace dev svc/simple-landmark 8080

Go in a browser window and copy-paste http://localhost:8080/api/museum/museum

Congratulations, you found a landmark!

Replicate the installation in qa project

Step1

According to Openshift documentation a project is a Kubernetes namespace with additional annotations, and is the central vehicle by which access to resources for regular users is managed. This means that a project offers you the ability to deploy Helm charts without specifying the namespace.

Create qa project and install a PostgreSQL instance:

$ oc new-project qa
$ helm install landmark-db \
--set postgresqlUsername=landmark-default,postgresqlPassword=postgres,postgresqlDatabase=landmark,persistence.enabled=false \
stable/postgresql
$ helm status landmark-db

Step2

Duplicate the values.yaml and rename it to values.qa.yaml. Change the NodePort value in values.qa.yaml to 31126. Install the charts:

$ helm install simple ./chart/landmark --values ./chart/landmark/values.qa.yaml
$ helm status simple
$ kubectl get ns
$ kubectl get svc
$ kubectl port-forward --namespace qa svc/simple-landmark 8080

Go in a browser window and copy-paste http://localhost:8080/api/museum/museum

Congratulations, you found a landmark and replicated deployment process accros environments!

In order to switch back to project dev, use the below command:

$ oc project dev

Validation and more

Looking to validate your charts? Checkout the validation branch: https://github.com/IBM/landmark/tree/validation/chart-per-service-lab

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Compatibility

The Java code in the repositories is compatible with Java11.

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License

This code is dedicated to the public domain to the maximum extent permitted by applicable law, pursuant to CC0.