5. Continuous Delivery Fundamentals

In this exercise, you will use Argo CD to automate the delivery of an application to a Kubernetes cluster.

Continuous Delivery (CD) is the ability to get code changes reliably to production environments. This practice should be automated and should enable developers to provide value to consumers efficiently.

Preparation

Prepare your environment by following Preparation section in the exercise 3. Kubernetes Cluster

Exercise 5.1 - Deploy the Application Using Argo CD

Install Argo CD by referring to the installation guide.
Expose the argocd-server using a NodePort service on port 30007 on HTTP and 30008 on HTTPS. The YAML manifest for the NodePost service can be found in the tutorial repository.
Access the Argo CD UI by going to https://192.168.50.4.30008 or https://192.168.50.4.30007.
Insert login credentials by using the credentials guide.
Create an Argo CD application named nginx-alpine and use the manifests provided in the course repository.

Configuration Managers

For the management of multiple declarative Kubernetes manifests, a templating layer is necessary, especially if the application is replicated across different regions. For this purpose configuration managers, such as Helm and Kustomize, were introduced.

This exercise will focus on creating your first Helm chart to deploy multiple Nginx applications using the same template and multiple input files.

Exercise 5.2 - Create a Helm Chart with Argo CD

Using the manifests provided in the course repository, create a helm chart (Chart.yaml, templates, values.yaml) that will template the following parameters:

namespace name
replica count
image:
- name
- tag
- pull policy
resources:
- requests for CPU and memory
service:
- port
- type (e.g. ClusterIP)
configmap data (e.g. the key-value pair)

The chart details should be as following:

name: nginx-deployment
version: 1.0.0
keywords: nginx

Exercise 5.3 - Create a YAML Values Files

Once the Helm chart is available make sure that a default values.yaml file is available. This values file will be used as a default input file for the Helm chart. The values.yaml file should have the following specification:

values.yaml

namespace name: demo
replica count: 3
image repository: nginx
image tag: alpine
image pull policy: IfNotPresent
resources: CPU 50m and memory 256Mi
service type: ClusterIP
service port: 8111
configmap data: “version: alpine”

Next, create two values files with the following specifications:

values-staging.yaml

namespace name: staging
replica count: 1
image repository: nginx
image tag: 1.18.0
resources: CPU 50m and memory 128Mi
configmap data: “version: 1.18.0”

values-prod.yaml

namespace name: prod
replica count: 2
image repository: nginx
image tag: 1.17.0
resources: CPU 70m and memory 256Mi
service port: 80
configmap data: “version: 1.17.0”

Exercise 5.4 - Create Argo CD Applications

Using the values files above (values-prod, values-staging), create two Argo CD applications, nginx-staging and nginx-prod respectively. These should deploy the nginx Helm Chart referencing each input values files.