Exercise 2¶

In this exercise you will complete the following:

Expand Ansible role to get the cluster domain name and save that in a fact
Expand the Ansible role to deply a helloworld application
Test the operator using the ansible-runner
Deploy operator to namespace so it runs without the ansible-runner

Step 1: Update Ansible role to get cluster domain name and save as a fact¶

Here we will learn to use the k8s Ansible module to gather information we want to use later in our automation. In this case the cluster domain name. Append the following tasks to the Ansible role.

We going to use following Asible `keywords:

nano roles/hello/tasks/main.yml

Content to addd to the main.yml:

- name: Get Application Domain from Cluster Ingress
  k8s_info:
    api_version: config.openshift.io/v1
    kind: Ingress
    name: cluster
  when: application_domain is undefined
  register: ingress

- name: Set Application Domain
  set_fact:
    application_domain: "{{ ingress.resources[0].spec.domain }}"
  when: application_domain is undefined

- name: Print application domain
  debug:
    msg: "Application domain is {{ application_domain }}"

Step 2: Run Operator using ansible-runner¶

Each time Operator is started or something changes with our CRD the Ansible role will run and our changes will of course be executed.

ansible-operator run local

In the Example output you see the execution of the predefined tasks in the main.yml.

Gathering Facts

--------------------------- Ansible Task StdOut -------------------------------
TASK [Gathering Facts] *********************************************************
-------------------------------------------------------------------------------
{"level":"info","ts":1612430621.8876169,"logger":"logging_event_handler","msg":"[playbook debug]","name":"hello-sample","namespace":"operator-helloworld","gvk":"cache.hello.example.com/v1, Kind=Hello","event_type":"runner_on_ok","job":"3916589616287113937","EventData.TaskArgs":""}

Hello World Task

--------------------------- Ansible Task StdOut -------------------------------
TASK [Hello World Task] ******************************** 
ok: [localhost] => {
    "msg": "Hello World! I live in a namespace called operator-helloworld"
}
"level":"info","ts":1612430621.8958986,"logger":"logging_event_handler","msg":"[playbook task]","name":"hello-sample","namespace":"operator-helloworld","gvk":"cache.hello.example.com/v1, Kind=Hello","event_type":"playbook_on_task_start","job":"3916589616287113937","EventData.Name":"hello : Get Application Domain from Cluster Ingress"}

hello : Get Application Domain from Cluster Ingress

-------------------------- Ansible Task StdOut -------------------------------
TASK [hello : Get Application Domain from Cluster Ingress] *********************
task path: /home/ubuntu/operator-helloworld/roles/hello/tasks/main.yml:8
"level":"info","ts":1612430622.4394364,"logger":"proxy","msg":"Skipping cache lookup","resource":{"IsResourceRequest":false,"Path":"/version","Verb":"get","APIPrefix":"","APIGroup":"","APIVersion":"","Namespace":"","Resource":"","Subresource":"","Name":"","Parts":null}}
....

Print application domain

--------------------------- Ansible Task StdOut -------------------------------
TASK [Print application domain] ******************************** 
ok: [localhost] => {
    "msg": "Application domain is rh-workshop-..000.us-south.containers.appdomain.cloud"
}
level":"info","ts":1612430626.1358507,"logger":"runner","msg":"Ansible-runner exited successfully","job":"3916589616287113937","name":"hello-sample","namespace":"operator-helloworld"}

PLAY RECAP

--------------------------- Ansible Task Status Event StdOut  -----------------
PLAY RECAP *********************************************************************
localhost                  : ok=5    changed=0    unreachable=0    failed=0    skipped=0    rescued=0    ignored=0

Step 3: Update Ansible role to deploy hellowoworld application¶

Now we will learn to use the k8s Ansible module to deploy an application. We will deploy a helloworld application that prints to STDOUT. Notice the route is using the cluster domain we gathered in the previous step. In this step we will create a deployment, service and route for our helloworld application. Append the following tasks to the Ansible role.

nano roles/hello/tasks/main.yml

We use k8s:definition: to define the Service, Deployment and Route

- name: Deploy helloworld service
  k8s:
    definition:
      apiVersion: v1
      kind: Service
      metadata:
        namespace: "{{ ansible_operator_meta.namespace }}"
        labels:
          app: helloworld
        name: helloworld
      spec:
        ports:
        - port: 8080
          targetPort: 8080
        selector:
          app: helloworld
          name: helloworld
      status:
        loadBalancer: {}

- name: Deploy helloworld app
  k8s:
    definition:
      kind: Deployment
      apiVersion: apps/v1
      metadata:
        name: helloworld
        namespace: "{{ ansible_operator_meta.namespace }}"
        labels:
          app: helloworld
      spec:
        replicas: 1
        strategy:
          type: RollingUpdate
        selector:
          matchLabels:
            app: helloworld
        template:
          metadata:
            labels:
              app: helloworld
              name: helloworld
          spec:
            containers:
            - image: openshift/hello-openshift
              imagePullPolicy: Always
              name: helloworld
              readinessProbe:
                httpGet:
                  path: /
                  port: 8080
                initialDelaySeconds: 60
                periodSeconds: 10
                timeoutSeconds: 60
              livenessProbe:
                httpGet:
                  path: /
                  port: 8080
                initialDelaySeconds: 120
                periodSeconds: 10
              ports:
              - containerPort: 8080
            restartPolicy: Always
        triggers:
        - type: ConfigChange

- name: Deploy helloworld route
  k8s:
    definition:
      apiVersion: route.openshift.io/v1
      kind: Route
      metadata:
        namespace: "{{ ansible_operator_meta.namespace }}"
        annotations:
          openshift.io/host.generated: "true"
        name: helloworld
      spec:
        host: "hello-{{ ansible_operator_meta.namespace }}.{{application_domain}}"
        to:
          kind: Service
          name: helloworld
          weight: 100
        port:
          targetPort: 8080
        wildcardPolicy: None

Step 4: Update role permissions¶

Since we are creating a service and route we need to add those permissions to the hello role, to add services so we can create them.

Open the role.yaml file. (More about roles)

nano config/rbac/role.yaml

Change the permissions.

##
## Rules for cache.hello.example.com/v1, Kind: Hello
##
  - apiGroups:
      - ""
    resources:
      - secrets
      - pods
      - pods/exec
      - pods/log
      - services
    verbs:
      - create
      - delete
      - get
      - list
      - patch
      - update
      - watch

Append also routes and ingress api groups so we can also manage those objects.

##
## Rules for cache.hello.example.com/v1, Kind: Hello
##
  ...
  ...
  - apiGroups:
    - ""
    - config.openshift.io
    resources:
    - ingresses
    verbs:
    - create
    - delete
    - deletecollection
    - get
    - list
    - patch
    - update
    - watch
  - apiGroups:
    - ""
    - route.openshift.io
    resources:
    - routes
    - routes/custom-host
    verbs:
    - create
    - delete
    - deletecollection
    - get
    - list
    - patch
    - update
    - watch

Step 5: Run Operator using ansible-runner¶

This time we should see the application being deployed. A single pod should start and a service/route should be created.

ansible-operator run local

Step 6: Test our deployment¶

To test simply use curl against the route URL. It does take a minute or so to start application.

pods:

oc get pods

Example output:

NAME                         READY   STATUS    RESTARTS   AGE
helloworld-f9d964dcc-jgcmn   1/1     Running   0          70s

* routes:

oc get routes