k8s-commands

Most common ways people install Kubernetes

• Minikube: For local developement
• kops and Kubeadm: For clouds and bare metal

General Management Tools

• Dashboard: Visualization
• Kubefed: For Larger cluster federation
• Kompose: For Exporting from docker with compose
• Helm: For Large application management

Creating a cluster:

When creating a cluster from an image, you will need to use the run command.

• kubectl run give-name-of-cluster --image repo-name/image-name:latest

Common way (from file): To use a yaml file within your local computer, use the command

• kubectl create -f file-2-deploy.yaml

Multiple files:

• kubectl create -f blue.yaml -f green.yaml

Whole directory:

• kubectl create ./colors

URL:

• kubectl apply -f https://raw.githubusercontent.com/karthequian/kubernetesHelloworld/master/hello.yaml

Using namespaces

Working with many applications

Deploy sample infrastructure:

• kubectl apply -f sample-infrastructure.yaml

Namespaces

• kubectl get pods returns no results.
• kubectl get pods --all-namespaces returns all our results.
• kubectl get namespaces Returns just the namespaces

Searching, sorting and filtering applications on kubernetes

More details

• kubectl get pods --sort-by=.metadata.name sorts pods by name
• kubectl get pods -o wide --all-namespaces returns more details
• kubectl get pods/cart-dev -n cart -o json returns the pod json
• kubectl get pods -n cart -o=jsonpath="{..image}" -l app=cart-dev searches cart-dev, and returns the image based on the jsonpath
• kubectl get pods --all-namespaces -o jsonpath="{.items[*]- .spec.containers[*].image}" all container images running

Understand how to delete pods, and resources in k8s

• kubectl delete pods --all deletes all pods in the default namespace
• kubectl delete pods -n cart --all deletes all pods in the cart namespace
• kubectl delete pods -l env=staging -n social Deletes the pods in the social namespace that match the staging environment

Kops with AWS

To use kops to run your own kubernetes cluster, you will need to the following.

Install and set

• kops
• kubectl
• AWS credentials
• AWS CLI tools

AWS requirements

• Set up IAM account: Give ut full access to s3, EC2, Route53, and IAM
• Create DNS record for the kubernetes services

Setup a cluster

• export NAME=mycluster.k8s.local
• export KOPS_STATE_STORE=s3://prefix-example-com-state-store

Build cluster

• kops create cluster \ --zones use-west-2b \ ${NAME}

Note: Kops create cluster command will result into a configuration file for what your cluster is going tro look like

Important: Important to verify that everything is the way kops expects.

• kops edit cluster cluster-name

Kops update command

• kops update cluster cluster-name

Build the cluster per spec

Check to see if everything is good.

• kubectl get nodes alert when nodes are ready
• kops validate cluster verify that everything works
• You can use terraform to provison that nodes. (Read more terraform)

Next on...

Microservices

Microservices: An oriented architecture that structures the entire application as a collection of loosely coupled services.