ERROR! no action detected in task, ansible - kubernetes

Question

I am using ansible version 2.5.1 with python version 2.7.17 and I installed an open shift.
The playbook looks like this:
---
- hosts: node 1
tasks:
- name: Create a k8s namespace
k8s:
name: CC_Namespace
api_version: v1
kind: Namespace
state: present
# Deployment Frontend
- name: Create a Frontend Deployment Object
k8s:
apiVersion: v1
kind: Deployment
metadata:
name: nginx-frontend-deployment
labels:
app: nginx
spec:
replicas: 4
selector:
matchLabels:
app: nginx
template:
metadata:
labels:
app: nginx
spec:
containers:
- name: nginx
image: nginx:1.7.9
ports:
- containerPort: 80
livenessProbe:
exec:
command:
- /ready
readinessProbe:
exec:
command:
- /ready
# Deployment Backend
- name: Create a Backend Deployment Object
k8s:
apiVersion: v1
kind: Deployment
metadata:
name: nginx-backend-deployment
labels:
app: nginx
spec:
replicas: 6
selector:
matchLabels:
app: nginx
template:
metadata:
labels:
app: nginx
spec:
containers:
- name: nginx
image: nginx:1.7.9 # change to Dockerfile
ports:
- containerPort: 80
livenessProbe:
exec:
command:
- /ready
readinessProbe:
exec:
command:
- /ready
# Service Backend
- name: Create a Backend Service Object
k8s:
apiVersion: v1
kind: Service
metadata:
name: cc-backend-service
spec:
selector:
app: CCApp
ports:
- protocol: TCP
port: 80
type: ClusterIP
# Serive Frontend
- name: Create a Frontend Service Object
k8s:
apiVersion: v1
kind: Service
metadata:
name: cc-frontend-service
spec:
selector:
app: CCApp
ports:
- protocol: TCP
port: 80
type: NodePort
and this is the error:
[WARNING]: provided hosts list is empty, only localhost is available. Note that the implicit localhost does not match 'all'
ERROR! no action detected in task. This often indicates a misspelled module name, or incorrect module path.
The error appears to have been in '/home/rocco/cc-webapp.yml': line 4, column 5, but may
be elsewhere in the file depending on the exact syntax problem.
The offending line appears to be:
tasks:
- name: Create a k8s namespace
^ here

Answer 1

The minimum ansible version to have k8s module available is 2.6. (Reference)
No choice, you have to upgrade.
Note: I tested your playbook syntax without any errors in ansible 2.9.2