Kubernetes
Workers-nodes Kube-proxy
how the end user interacts w. your applications..... maintains network rules on nodes. These network rules allow network communication to your Pods from network sessions inside or outside of your cluster
Master components: etcd
Primary datastore for Kubernetes... stores all k8 info stauts certificates date of creation .. Storing and replicating all kubernetes cluster state
what are replicas
how many pods you want running if you delete on kubernetes will automatically create new one
List the nodes in your cluster, along with their labels:
kubectl get nodes --show-labels
shows pods
kubectl get pods
Kubernetes
Container Orchestration tool. Allows to easily build and manage containers. Most popular one. Manages deployment updates scales
Deployment
Desire state
command to join node to cluster -init cluster - create dir and change ownership -Calico network -command to run on worker
INIT CLUSTER kubeadm init --config kubeadm.yml in output youll see * to start using cluster* mkdir -p $HOME/.kube sudo cp -I /etc/kubernetes/admin.conf $HOME/.kube/config sudo chown $(id -u):$(id -g) $HOME/.kube/config NETWORK kubectl apply -f https://docs.projectcalico.org/v3.14/manifests/calico.yaml GIVES U COMMAND TO RUN ON WORKER kubeadm token create --print-join-command
Node
Instance of a computer. Nodes run pods
Master components: scheduler
assign unassign objects to pods, and assign pods to nodes (workers)... we don't get to choose
Master components: api-server
cannot do anything in k8 w.out it... validates and configure data for -pods, -servicers, -replicationcontrollers... all components of master and worker............................. many versions of api servers depending on deployment
go inside contINER
docker exec -it (node-id) sh
Master components: controller-manager
is a control loop that watches the shared state of the cluster through the apiserver and makes changes attempting to move the current state towards the desired state............... will automatically launch new pods, give new status
Pod
is a group of containers that exists within nodes, are deployed together on the same host.
Kubelet
is the application that is running that helps NODE communicate w. master.
to see what node your pod is connected to see IP see status- running, pending
kubctl get pods --all-namespaces -o wide
command to run on worker
kubeadm token create --print-join-command
install network plugin CALICO
kubectl apply -f https://docs.projectcalico.org/v3.14/manifests/calico.yaml
installing the ingress
kubectl apply -f https://ingressURL.yaml kubectl get ingress
.yaml create apply delete
kubectl create -f config-map.yaml kubectl apply -f config-map.yaml kubectl delete config-map.yaml
create deployment w. yml file
kubectl create -f deployment.yml (-f is for file)
create deployment nginx
kubectl create deployment nginx --tcp 80:80
create a dev namespace
kubectl create namespace dev
create service nginx
kubectl create service nodeport nginx --tcp 80:80
go inside node
kubectl exec -it (node-id) sh
shows deployment
kubectl get deployments
0check all namespacesb
kubectl get pods --all-namespaces
gets the pods for the dev namespace
kubectl get pods -n dev
get svc
kubectl get svc
ingress
loadbalancer between apps
Workers-nodes Kubelet
monitoring the Object Store for assigned Pods, will execute the Pod..................... .connection btwn worker and master
remove taint from master-
taint nodes $(hostname) node-role.kubernetes.io/master:NoSchedule
creating app apple accessing app
vi apple.yaml kubectl create -f apple.yaml kubectl apply -f apple.yaml kubectl get svc curl -kL http://custerIP/apple
