Deployment Of Kubernetes
A Deployment provides declarative updates for Pods and ReplicaSets.
You describe a desired state in a Deployment, and the Deployment Controller changes the actual state to the desired state at a controlled rate. You can define Deployments to create new ReplicaSets, or to remove existing Deployments and adopt all their resources with new Deployments
Actual Overflow of Deployment
Most Important part about to notice that, AUTO Healing behaviours
Let's Dive into the actual Implimentations
Create deployment.yaml file
apiVersion: apps/v1
kind: Deployment
metadata:
name: nginx-deployment
labels:
app: nginx
spec:
replicas: 3
selector:
matchLabels:
app: nginx
template:
metadata:
labels:
app: nginx
spec:
containers:
- name: nginx
image: nginx:1.14.2
ports:
- containerPort: 80
apiVersion: apps/v1
- Specifies the API version for the Deployment object. apps/v1 is the stable version for managing applications.
kind: Deployment
- Defines the type of Kubernetes object. In this case, it's a Deployment, which manages a set of replicated Pods.
metadata:
Contains data to uniquely identify the Deployment object.
name: nginx-deployment
- The name of the Deployment. It uniquely identifies this Deployment within the namespace.
labels:
A set of key-value pairs for categorizing and selecting the Deployment.
app: nginx
- A label with key app and value nginx to categorize this Deployment as part of the nginx application.
spec:
Defines the desired state for the Deployment.
replicas: 3
- Specifies the number of Pod replicas to run. In this case, 3 Pods.
selector:
Determines how the Deployment finds which Pods to manage.
matchLabels:
A set of key-value pairs that the Deployment uses to select Pods.
app: nginx
- Selects Pods with the label app: nginx.
template:
Describes the Pods that will be created by this Deployment.
metadata:
Metadata for the Pods.
labels:
Labels assigned to the Pods created by this template.
app: nginx
- Pods will be labeled with app: nginx.
spec:
Specifies the configuration for the Pods.
containers:
A list of containers that will run in each Pod.
name: nginx
- Defines a container named nginx.
image: nginx:1.14.2
- Specifies the container image to use. In this case, it uses nginx version 1.14.2
ports:
Defines a list of ports to expose from the container.
containerPort: 80
- Exposes port 80 from the container, which is the default HTTP port for nginx.
to execute the deployment.yaml file
kubectl apply -f deployment.yaml
Let's Test some AUTO Healing Feature,how actually work
We will Delete a pod
In Other terminal we will see the live change which replicaset try to heal
