learn_yaml_files.md

Kubernetes yaml file deployments

Yaml file definition

https://kubernetes.io/docs/user-guide/walkthrough/

The simplest pod definition describes the deployment of a single container. For example, an nginx web server pod might be defined as such:

apiVersion: v1
kind: Pod
metadata:
  name: nginx
spec:
  containers:
  - name: nginx
    image: nginx:1.7.9
    ports:
    - containerPort: 80

liveness probes and variables

https://kubernetes-v1-4.github.io/docs/user-guide/liveness/

Ensure that health checks are performed against your instance

apiVersion: v1
kind: Pod
metadata:
  name: nginx
  #namespace: default
spec:
  containers:
  - name: nginx
    image: nginx:1.7.9
    ports:
    - containerPort: 80
    env:       
      - name: "SOMEVARIABLE"
        value: "somevalue"
    livenessProbe:
      httpGet:
        path: /
        port: 80
      initialDelaySeconds: 15
      timeoutSeconds: 1

Referencing images from your own registry

To allow for authentication to your azure container registry make sure that your kubernetes service principal has at least Reader permissions on your container registry: https://github.com/MicrosoftDocs/azure-docs/blob/master/articles/container-registry/container-registry-auth-aks.md

For this to work first find out the ClientId of your cluster by listing all clusters and their clientids:

az aks list --query '[0].{Name:name, ClientId:servicePrincipalProfile.clientId}' -o table

Now retrieve the id of your azure container registry:

az acr list --query '[0].{Name:name, Id:id}' -o table

Now you assign your Kubernetes ClientId the permission to pull images from your registry by granting these permissions on the scope of your registry id:

REGISTRY_ID=
CLUSTER_CLIENT_ID=
az role assignment create --scope $REGISTRY_ID --role Reader --assignee $CLUSTER_CLIENT_ID

After this assignment has been done you can reference an image from your azure container registry using this sample yaml.

apiVersion: "v1"
kind: Pod
metadata:
  name: somePodName
  labels:
    name: someLabelName
spec:
  containers:
    - name: blue
      image: someRegistryOnAzure.azurecr.io/someImage:latest
      ports:
        - containerPort: 80
          protocol: TCP