KOPS - Kubernetes OPerationS ¶

KOPS is my favourite goto tool to setup full fledged Kubernetes distribution in matter of 5-6 minutes. KOPS has a lot of customization options so you can easily create a production grade kubernetes infrastructure in KOPS. Cluster upgrade, cluster autoscaling, etc. are also supported via configuration changes via addons. All the changes can be previewed first (dry-run) and then applied to cluster.

Important points about KOPS:

KOPS supports AWS and GKE cloud only.
It also supports public and private clusters.
KOPS creates AutoScalingGroups (in AWS) for master and for nodes. You can easily scale horizontally and vertically by changing ASG (via KOPS CLI. Direct AWS change are not required and recommended).
All the changes in KOPS are expected to done via configuration changes. Entire configuration is expressed via YAML. Detaild documentation of cluster API is here.

To create KOPS cluster you can either pass params to kops create cluster command OR you can profile a yaml file with all the details using kops create -f kops-spec.yaml Below cheatsheet can help you get KOPS cluster created by running 5-6 commands in both ways.

# read more here
https://kops.sigs.k8s.io/getting_started/aws
 
# name of your cluster. .k8s.local means private cluster
export NAME=kopsdemo.k8s.local

# must create one bucket for storage of kops artifacts.. and provide its reference below. Below bucket is my bucket. You must create your own.
export KOPS_STATE_STORE=s3://kops-sample-state-store

# AWS credentials for KOPS to use.. You can use AWS_PROFILE / AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY combination. The IAM user must have [sufficient](https://kops.sigs.k8s.io/getting_started/aws/#setup-iam-user) permissions.
export AWS_PROFILE=vj

# Options 1 - Create cluster by passing params. (This is less flexible way)
# You can customize zones as per your convenience
kops create cluster --zones=ap-south-1a --node-count 1 \
  --node-size t3a.small \
  --master-volume-size 30 \
  --node-volume-size 30 \
  --master-size t3a.small  ${NAME}

# Options 2 - Using spec.yaml
kops create cluster  --zones=ap-south-1a --dry-run -o yaml $NAME  > kops-cluster.yaml
kops create -f kops/kops-cluster.yaml

# customize to provide your own public key. This will be used to allow ssh based login to master and worker nodes.
kops create secret --name ${NAME} sshpublickey admin -i ~/.ssh/dharapvv.pub

# You can skip --yes param below to dry-run your changes.
# --admin downloads admin kubeconfig for you to use
kops update cluster ${NAME} --yes --admin
# newer versions of kops force you to manually download kubeconfig with admin priviledges
# kops export kubecfg ${NAME} --admin
kops validate cluster --wait 10m

# Later on more customizations to instance groups etc can be done and cluster can be updated again
kops get ig
kops edit ig nodes-XXXX # XXXX will be your AWS region
kops update cluster ${NAME} --yes --admin

# If you want to delete the cluster, use below command
kops delete cluster --name ${NAME} --yes