5. Continuous Delivery Fundamentals

Note

The preparation steps are the same as in the exercise 3. Kubernetes Cluster Make sure you have prepared the environment

Solution 5.1 - Deploy the Application Using ArgoCD

Quick Start with ArgoCD

1. Open Vagrant shell using command:

vagrant ssh

2. Create namespace:

kubectl create namespace argocd

3. Install ArgoCD:

kubectl apply -n argocd -f https://raw.githubusercontent.com/argoproj/argo-cd/stable/manifests/install.yaml

3. Check ArgoCD pods:

kubectl get po -n argocd

4. Get all application services:

kubectl get svc -n argocd

Create and Apply YAML Manifests

Warning

Do not forget to change GITHUB_USERNAME inside the YAML files below to your GitHub user name!

argocd-server-nodeport.yaml

1. Create a file within the vim shell: vim argocd-server-nodeport.yaml

2. Write the manifest:

apiVersion: v1
kind: Service
metadata:
  annotations:
  labels:
    app.kubernetes.io/component: server
    app.kubernetes.io/name: argocd-server
    app.kubernetes.io/part-of: argocd
  name: argocd-server-nodeport
  namespace: argocd
spec:
  ports:
  - name: http
    port: 80
    protocol: TCP
    targetPort: 8080
    nodePort: 30007
  - name: https
    port: 443
    protocol: TCP
    targetPort: 8080
    nodePort: 30008
  selector:
    app.kubernetes.io/name: argocd-server
  sessionAffinity: None
  type: NodePort

3. Escape the vim shell: esc

4. Save changes: :wq

5. Check the manifest: cat argocd-server-nodeport.yaml

6. Apply the manifest: kubectl apply -f argocd-server-nodeport.yaml

nginx-alpine.yaml

1. Create a file within the vim shell: vim nginx-alpine.yaml

2. Write the manifest:

apiVersion: argoproj.io/v1alpha1
kind: Application
metadata:
  name: nginx-alpine
  namespace: argocd
spec:
  destination:
    namespace: default
    server: https://kubernetes.default.svc
  project: default
  source:
    path: solutions/kubernetes/manifests
    repoURL: https://github.com/GITHUB_USERNAME/cloud-native-foundations
    targetRevision: HEAD
  # Sync policy
  syncPolicy: {}

3. Escape the vim shell: esc

4. Save changes: :wq

5. Check if everything was written correctly: cat nginx-alpine.yaml

6. Apply created yaml manifest:: kubectl apply -f nginx-alpine.yaml

After preparing all the required manifests, check the application using the command:

kubectl get application -n argocd

Use ArgoCD in your browser at

• http://192.168.50.4.30007

• http://192.168.50.4.30008

Solutions 5.2 - Create a Helm Chart with ArgoCD

The Helm chart is defined in the Chart.yaml file, which contains the API version, name and version of the chart:

apiVersion: v1
name: nginx-deployment
description: Install Nginx deployment manifests
keywords:
  - nginx
version: 1.0.0
maintainers:
  - name: GITHUB_USERNAME

Solution 5.3 - Create a YAML Values Files

An example of the values.yaml file:

namespace:
  name: demo
service:
  port: 8111
  type: ClusterIP
image:
  repository: nginx
  tag: alpine
  pullPolicy: IfNotPresent
replicaCount: 3
resources:
  requests:
    cpu: 50m
    memory: 256Mi
configmap:
  data: "version: alpine"

The above configuration represents the default parameters of application deployment if it is not overwritten by a different values file.

Below is an example of the values-prod.yaml file, which will override the default parameters:

namespace:
  name: prod
service:
  port: 80
  type: ClusterIP
image:
  repository: nginx
  tag: 1.17.0
  pullPolicy: IfNotPresent
replicaCount: 2
resources:
  requests:
    cpu: 70m
    memory: 256Mi
configmap:
  data: "version: 1.17.0"

Solution 5.4 - Create ArgoCD Applications

ArgoCD application CRD for the nginx-prod.yaml deployment:

apiVersion: argoproj.io/v1alpha1
kind: Application
metadata:
  name: nginx-prod
  namespace: argocd
spec:
  destination:
    namespace: default
    server: https://kubernetes.default.svc
  project: default
  source:
    helm:
      valueFiles:
        - values-prod.yaml
    path: helm
    repoURL: https://github.com/GITHUB_USERNAME/cloud-native-foundations/tree/main/solutions/argocd
    targetRevision: HEAD

Note

The nginx-staging.yaml, values-staging.yaml, and nginx-prod.yaml files can be found in the project repository solutions/helm/nginx-deployment

Common Errors & How to Fix Them

Error Validating Data

Pay attention when copying/pasting to build manifests! The letter a on the first line of a created manifest is usually lost after the file is saved. This error turns apiVersion into piVersion and raises the following error:

Error

error: error validating "argocd-server-nodeport.yaml": error validating data: apiVersion not set; if you choose to ignore these errors, turn validation off with --validate=false

To fix Error Validating Data, open the yaml file you working on and correct the typo by turning piVersion back to apiVersion.