Demo Walkthrough

Prereqs

See setup. Before attempting the walkthrough you should run this script:

${DEMO_HOME}/scripts/prepare-demo.sh

If the script ran successfully, you should see the following output:

NAME            STATUS   AGE
operator-test   Active   55s
namespace "operator-test" deleted
customresourcedefinition.apiextensions.k8s.io "appops.org.mhildenb.operatortutorial" deleted
namespace/operator-test created
Context "minikube" modified.
customresourcedefinition.apiextensions.k8s.io/appops.org.mhildenb.operatortutorial created
deployment.apps/demo-app created
Waiting for deployment "demo-app" rollout to finish: 0 of 1 updated replicas are available...
deployment "demo-app" successfully rolled out
demo-app successfully deployed
namespace/demo-operator unchanged
serviceaccount/demo-operator created
clusterrolebinding.rbac.authorization.k8s.io/operator-admin configured
deployment.apps/demo-operator created
Waiting for deployment "demo-operator" rollout to finish: 0 of 1 updated replicas are available...
deployment "demo-operator" successfully rolled out
demo-operator successfully deployed

Terminal Setup

For this demo VSCode is assumed. Make sure you have 4 terminals all with a kubernetes context pointing to the namespace operator-test. Click the tabs below to see information about each terminal and any initial commands that need to be run

  • Terminal 1

  • Terminal 2

  • Terminal 3

  • Terminal 4

Terminal one will be used for running local build commands and will be particularly important if showing a locally running build

Terminal 2 will be our CR watch window. This is where we’ll see updates to our CustomResource.

Run the following command to get it started:

# watch updates every second with this command
watch -t -d -n 1 -x -- kubectl patch appops/my-bespoke-app -o yaml --type='json' -p='[{"op": "remove", "path": "/metadata/managedFields" }, {"op": "remove", "path": "/metadata/annotations" } ]' --dry-run=client

The third terminal should be running the logs of the application (which will initially be more verbose than specified in the AppOps custom resource.

Run the following command to get this terminal ready:

# start logging the demo app
stern demo-app --since=1s -n operator-test

The fourth terminal is used for issuing k8 commands

When you’ve finished, your terminals should look something like this (though the content will not be the same at this point)

cr terminals

Demo 1: Intro to the application

  1. Make a call to the hello endpoint

    curl ${DEMO_OPERATOR_POD_URI_OVERRIDE}/hello
    hello%

  2. Next show terminal 3’s logs and how its logging at a INFO level

  3. Show our app’s AppOps in vscode by opening appops-crd.yaml quickly

  4. In the 4th terminal, show that the demo operator is running

    kubectl get deploy/demo-operator
    NAME            READY   UP-TO-DATE   AVAILABLE   AGE
demo-operator   1/1     1            1           8m

  5. Explain that the watch window, terminal 2 is watching the CR we’re about to create

    kubectl apply -f ${DEMO_HOME}/demo/kube/myapp-cr.yaml

  6. Once the CR is applied, you should see the watch window change and the logging get less verbose

    cr terminals

Demo 2: Show Operator Responding to Site Load

  1. Run the following command to increase load threshold

    • Terminal 4

    hey -n 30 -c 30 -q 1 ${DEMO_OPERATOR_POD_URI_OVERRIDE}/hello

  2. You should then see the information in the CR change as well as the app’s logging get more verbose:

    cr load

Other things to try

Edit the Custom Resource directly

  1. Edit the Custom Resource directly

    • Terminal 4

    kubectl edit appops

  2. Change something like the defaultLogThreshold and save the edit

  3. Notice that the watch in Terminal 2 updates and the logs of the pod in Terminal 3 has changed accordingly

Increase the number of pods

  1. Run the following command to increase the number of pods

    • Terminal 4

    kubectl patch deploy/demo-app --type='json' -p='[{"op": "replace", "path": "/spec/replicas", "value": 2 }]'

  2. Notice how the custom resource changes in Terminal 2 as it should now show multiple pods

Demo 3: Run the operator in the debugger to show how it works

To run this demo you will need to run some setup first

  1. First setup your environment accordingly

    • Terminal 1

    Make sure the following environment variables are set:

    • DEMO_OPERATOR_POD_URI_OVERRIDE=http://192.168.86.87:8008

    • LOG_MODULE_TEST_INTEGRATION_URI=http://192.168.86.87:8008

    • USER=<your quay.io user>

    • PASSWORD=<your quay.io password>

  2. Remove the operator from the cluster

    • Terminal 4

    kubectl delete deploy/demo-operator

  3. Run the following to start the app running locally

    • Terminal 1

    cd ${DEMO_HOME}/demo/demo-operator
mvn quarkus:dev -Dsuspend

  4. the -Dsuspend means that the operator will not move on until you connect the debugger

    Before demonstrating in the debugger make sure:

    • Number of pods is set to 0

    • DEMO_OPERATOR_POD_URI_OVERRIDE=http://192.168.86.87:8008