Kube && Helm

- K8s how to collect metrics

- How to debug Kubernetes Ingress

- Monitoring, Logging and Alerting in Kubernetes

kubectl get pods -A

helm repo add prometheus https://prometheus-community.github.io/helm-charts

helm upgrade --install prometheus prometheus/prometheus --namespace monitoring --create-namespace

kubectl get pods --namespace monitoring -l "app.kubernetes.io/name=prometheus,app.kubernetes.io/instance=prometheus" -o jsonpath="{.items[0].metadata.name}"

- Horizontal Pod Autoscaler Custom Metrics & Prometheus: K8s and EKS)

- How to install Metrics Server on Kubernetes cluster

- PromCon 2017: lighting talk - kube-state-metrics- Fredric Branczyc

- Secret way to learn K8S

Cert manageer

- Kubernetes Cert Manager explained

- Install kind on debian

sudo apt-get clean

sudo rm -rf /var/lib/apt/lists/*

sudo apt-get update

- Install kubernetes

echo "deb [signed-by=/etc/apt/keyrings/kubernetes-apt-keyring.gpg] https://pkgs.k8s.io/core:/stable:/v1.29/deb/ /" | \

sudo tee /etc/apt/sources.list.d/kubernetes.list

sudo apt update
sudo apt install -y kubelet kubeadm kubectl

- Kind to create cluster

rm -rf /etc/cni/net.d

rm -rf /var/lib/cni

rm -rf /var/lib/kubelet

systemctl restart containerd

systemctl restart kubelet

mkdir -p $HOME/.kube

kubeadm version
containerd --version
uname -a

kubeadm init

sudo kubeadm init --pod-network-cidr=10.244.0.0/16

kubectl get pods -n kube-system

kubectl taint nodes --all node-role.kubernetes.io/control-plane-

kubectl apply -f https://github.com/flannel-io/flannel/releases/latest/download/kube-flannel.yml --validate=fals

snap install helm --classic

helm repo add jetstack https://charts.jetstack.io

helm repo update

kubectl create namespace cert-manager

kubectl apply -f https://github.com/cert-manager/cert-manager/releases/latest/download/cert-manager.crds.yaml

sudo mkdir -p /usr/lib/cni
sudo ln -s /opt/cni/bin/* /usr/lib/cni/

sudo systemctl restart containerd
sudo systemctl restart kubelet

kubectl delete pod -n cert-manager --all

ping -c 4 8.8.8.8

sudo mkdir -p /usr/lib/cni
sudo ln -sf /opt/cni/bin/* /usr/lib/cni/

helm install cert-manager jetstack/cert-manager --namespace cert-manager --version v1.14.4

kubectl get pods -n cert-manager

kubectl logs cert-manager-6dc66985d4-grlsd -n cert-manager

kubectl get all -n cert-manager

kubectl create ns cert-manager-test

cd work/

mkdir self-signes-k8s

vi issuer.yaml

vi certificate.yaml

kubectl describe certificate -n cert-manager-test

Normal Issuing 68s cert-manager-certificates-trigger Issuing certificate as Secret does not exist

Normal Generated 68s cert-manager-certificates-key-manager Stored new private key in temporary Secret resource "selfsigned-cert-4jgzm"

Normal Requested 68s cert-manager-certificates-request-manager Created new CertificateRequest resource "selfsigned-cert-1"

Normal Issuing 68s cert-manager-certificates-issuing The certificate has been successfully issued

kubectl get secrets -n cert-manager-test

kind: Secret

metadata:

annotations:

cert-manager.io/alt-names: example.com

cert-manager.io/certificate-name: selfsigned-cert

cert-manager.io/common-name: ""

cert-manager.io/ip-sans: ""

cert-manager.io/issuer-group: ""

cert-manager.io/issuer-kind: ""

cert-manager.io/issuer-name: test-selfsigned

cert-manager.io/uri-sans: ""

- Deploy an ingress controller

kubectl create ns ingress-nginx

kubectl -n ingress-nginx get pods

kubectl -n ingress-nginx apply -f https://raw.githubusercontent.com/kubernetes/ingress-nginx/controller-v0.41.2/deploy/static/provider/baremetal/deploy.yaml

kubectl -n ingress-nginx get pods

- Implement cert-manager PDB

cat pdb.yml

apiVersion: policy/v1

kind: PodDisruptionBudget

metadata:

name: nginx

spec:

minAvailable: 2

selector:

matchLabels:

app: cert-manager