CS548_Extending

CS-548: Cloud-native Software Architectures Computer Science Department • University of Crete. Assignment 4: Extending.

Part1:

• Install the custom resource:

  kubectl apply -f fruits-crd.yaml

  we get: customresourcedefinition.apiextensions.k8s.io/fruits.hy548.csd.uoc.gr created

• Create the above instance.

  kubectl apply -f fruits.yaml

  we get:

  fruit.hy548.csd.uoc.gr/apple created
  fruit.hy548.csd.uoc.gr/orange created
  fruit.hy548.csd.uoc.gr/banana created
  

• Return the new instance in YAML format.

  kubectl get fruit apple -o yaml

  we get:

  apiVersion: hy548.csd.uoc.gr/v1
  kind: Fruit
  metadata:
    annotations:
      kubectl.kubernetes.io/last-applied-configuration: |
        {"apiVersion":"hy548.csd.uoc.gr/v1","kind":"Fruit","metadata":{"annotations":{},"name":"apple","namespace":"default"},"spec":{"count":3,"grams":980,"origin":"Krousonas"}}
    creationTimestamp: "2024-05-22T11:13:52Z"
    generation: 1
    name: apple
    namespace: default
    resourceVersion: "254065"
    uid: 6f516102-d3ba-41a5-92c1-d9f87ffaf32a
  spec:
    count: 3
    grams: 980
    origin: Krousonas  
  

• Return a list of all available instances.

  kubectl get fruits

  we get:

  NAME     AGE
  apple    34m
  banana   34m
  orange   34m
  

  Part2:

After copying nessecery files from hy548 github repo (controller.py, greeting-crd.yaml, hello-world.yaml, kubeclient.py, requirements.txt). We can proceed to create the Dokerfile and greeting-controller.yaml.

a) For the dockerfile build and push:

docker build -t thodorisp/greeting-controller:latest .

docker push thodorisp/greeting-controller:latest

b) For applying greeting-crd and greeting-controller:

kubectl apply -f greeting-crd.yaml
customresourcedefinition.apiextensions.k8s.io/greetings.hy548.csd.uoc.gr created

kubectl apply -f greeting-controller.yaml
clusterrole.rbac.authorization.k8s.io/greeting-controller-role created
clusterrolebinding.rbac.authorization.k8s.io/greeting-controller-binding created
serviceaccount/greeting-controller created
deployment.apps/greeting-controller created

To verify we run :

kubectl get deployments

we get :

NAME                  READY   UP-TO-DATE   AVAILABLE   AGE
greeting-controller   1/1     1            1           21m

kubectl get pods -l app=greeting-controller

we get:

NAME                                  READY   STATUS    RESTARTS   AGE
greeting-controller-674597955-rt2br   1/1     Running   0          23m

kubectl logs -l app=greeting-controller

we get:

2024-05-22 18:14:38 INFO check_and_apply: Working in namespace: default
2024-05-22 18:14:38 INFO check_and_apply: Found crd: hello-to-all (message: Hello to all!, replicas: 3)
2024-05-22 18:14:38 INFO check_and_apply: Service already created. Skipping...
2024-05-22 18:14:38 INFO check_and_apply: Found crd: hello-world (message: Hello world!, replicas: 2)
2024-05-22 18:14:38 INFO check_and_apply: Service already created. Skipping...
2024-05-22 18:14:38 INFO check_and_apply: Working in namespace: ingress-nginx
2024-05-22 18:14:38 INFO check_and_apply: Working in namespace: kube-node-lease
2024-05-22 18:14:38 INFO check_and_apply: Working in namespace: kube-public
2024-05-22 18:14:38 INFO check_and_apply: Working in namespace: kube-system
2024-05-22 18:14:38 INFO check_and_apply: Working in namespace: kubernetes-dashboard

kubectl get greetings

we get:

NAME           AGE
hello-to-all   17m
hello-world    17m

Part 3:

After copying nessecery files from hy548 github repo (controller.py, webhook.yaml, requirements.txt). We can proceed to create the Dokerfile. For the dockerfile build and push:

docker build -t thodorisp/controller-app:v2 .

docker push thodorisp/controller-app:v2

Update Webhook Configuration:

Update the IP address in the webhook.yaml file to your local IP address. Replace the image reference with your Docker image in webhook.yaml. update this part in the webhook.yaml:

spec:                         
    containers:
    - image: thodorisp/controller-app:v1 #here
      name: webhook-controller
      env:
      - name: CUSTOM_LABEL
        value: "custom-label"  #here
      ports:
      - containerPort: 8000

then apply the webhook:

kubectl apply -f webhook.yaml

we get :

namespace/custom-label-injector unchanged
issuer.cert-manager.io/issuer-selfsigned created
certificate.cert-manager.io/controller-certificate created
service/controller unchanged
configmap/controller-proxy-config unchanged
deployment.apps/controller unchanged
mutatingwebhookconfiguration.admissionregistration.k8s.io/custom-label-injector configured

Create Test Namespace:

kubectl create namespace test

Label the "test" namespace to enable the custom-label-injector:

kubectl label namespace test custom-label-injector=enabled

create a test yaml file:

apiVersion: v1
kind: Pod
metadata:
  name: test-pod
  namespace: test
spec:
  containers:
  - name: nginx
    image: nginx:latest

And apply kubectl apply -f test.yaml

You can verify the deployment by running:

kubectl get deployments -n custom-label-injector

And to see the pods created by the deployment:

kubectl get pods -n custom-label-injector

we get:

NAME                          READY   STATUS    RESTARTS   AGE
controller-548699cd59-rj2lw   1/1     Running   0          22m

we can see the pods in the test namespace:

kubectl get pods -A