# api version of the kubernetes : apps/v1 -current stable
apiVersion: apps/v1


# Kind describes the type of the object/resource to be created.
# Supported kind are :
### componentstatuses
### configmaps
### daemonsets
### deployments
### events
### endpoints
### horizontalpodautoscalers
### ingress
### jobs
### limitranges
### namespaces
### nodes
### pods
### persistentvolumes
### persistentvolumeclaims
### resourcequotas
### replicasets
### replicationcontrollers
### serviceaccounts
### services
kind: Deployment
# Set of data to uniquely identify K8 objects
# It takes:
# labels
# name
# namespace
# annotations
metadata:
  name: nginx-deployment #Name of the deployment created
  #  Key-value pairs primarily used to group and categorize deployment object.
  #  It is intended for an object to object grouping and mapping using selectors.
  # kubernetes service uses the pod labels in its selectors to send traffic to the right pods.
  labels:
    app: nginx
# declare the desired state and characteristics of the object we want to have
# Spec has three important subfields:
## replicas
## selector
## template
spec:
# replicas - It will make sure the numbers of pods running all the time for the deployment
  replicas: 3
# Selector - It defines the labels that match the pods for the deployments to manage.
  selector:
    matchLabels:
      app: nginx
# Template - It has its own metadata and spec. Spec will have all the container information a pod should have.
# Container image info, port information, ENV variables, command arguments etc.
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - name: nginx
        image: nginx:1.7.9
        ports:
        - containerPort: 80