Phippy Goes to the Zoo
Managed Kubernetes
- Managed K8s is k8s offered as a service by cloud providers.
- Azure offers AKS (Azure kubernetes service) & AWS offer EKS
- Managed K8s means
- control plane is managed by cloud
- Managed k8s offers
- load balancers to integrate with k8s
- storage services for persistence
- managing secrets effectively with vaults
- easy adminstration.
Lets create an AKS Cluster
- Ensure Azure CLI is installed and connected to your subscription
az login
- Install kubectl
- creating k8s cluster in azure
- Create the following variables
- linux or mac
export MY_RESOURCE_GROUP_NAME="myAKSResourceGroup"
export REGION="eastus"
export MY_AKS_CLUSTER_NAME="myAKSCluster"
export MY_DNS_LABEL="mydnslabel"
$MY_RESOURCE_GROUP_NAME="myAKSResourceGroup"
$REGION="eastus"
$MY_AKS_CLUSTER_NAME="myAKSCluster"
$MY_DNS_LABEL="mydnslabel"
az group create --name $MY_RESOURCE_GROUP_NAME --location $REGION
az aks create --resource-group $MY_RESOURCE_GROUP_NAME --name $MY_AKS_CLUSTER_NAME --node-count 1 --generate-ssh-keys --node-vm-size "Standard_B2ms"
Service
- Refer Here for official docs
- A Service when created gets an virtual ip address which is fixed.
- A service is made of endpoints, Endpoint is a pod with ip on a specific port
- service types
- ClusterIP: This is default type of k8s service which is internal within cluster.
- Node Port: Expose the application via a port on the node
- Load Balancer: Exposes the application via load balancer (Used in managed k8s clusters)
- ExternalName: Services of type ExternalName map a Service to a DNS name
- A service with in k8s cluster can be accessed by name or ip.
- Name resolution of service works in this fashion
- A fqdn of service is generally
<svc-name>.<namespace>.svc.cluster.local
nginx-internal.default.svc.cluster.local
- Refer Here for different manifests and classroom video for
- exploring nslookups
- different types of services with examples.
Deployments
- Refer Here for official docs
- k8s has two types of stragies for deployment
- RollingUpdate: This is default which ensures by default only 25% of your workload updates happen
- Recreate
-
K8s Deployments have options to undo rollout or go back to previous versions & this is supported by Daemonsets & stateful sets as well
-
Lets discuss this in our next session
- health checks
- deployments
- job/cronjob
- config maps
- secrets
