Manages a set of pods by describing the desired state thru K8s ReplicaSet by sending configurations to it
when update deployment, it mades new replicaset then turn on pods in it and delete in old one
Represents a group of replicas of the same Pod and keeps your Pods running even when the nodes they run on fail.
Heterogeneous deployments:
typically involve connecting two or more distinct infrastructure environments or regions to address a specific technical or operational need.
called “hybrid”, “multi-cloud”, or “public-private”, depending upon the specifics of the deployment.
Kubernetes creates a Service with a fixed IP address for your Pods, and a controller says
”I need to attach an external Load balancer with a public IP address to that Service so others outside the cluster can access it.”
Master node vs workder note
apiVersion: apps/v1kind: Deploymentmetadata: name: nginx-deploymentspec: selector: matchLabels: app: nginx replicas: 2 # tells deployment to run 2 pods matching the template template: metadata: labels: app: nginx # key-value pairs used in kubectl command spec: containers: - name: nginx image: nginx:1.14.2 ports: - containerPort: 80
Create deployment
kubectl create deployment —image nginx nginx-1
When a repository isn’t specified, the default behavior is to try and find the image either locally or in the Docker public registry. In this case, the image is pulled from the Docker public registry.