# kubernetes.txt
https://www.youtube.com/watch?v=o6bxo0Oeg6o&t=130s
https://kubernetes.io/docs/setup/production-environment/tools/kubeadm/
install-kubeadm/

Installing a container runtime
Install Docker Engine on Ubuntu
=============
1.Set up Docker's apt repository.

# Add Docker's official GPG key:
sudo apt-get update
sudo apt-get install ca-certificates curl gnupg
sudo install -m 0755 -d /etc/apt/keyrings
curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo gpg --dearmor -o /etc/apt/keyrings/docker.gpg
sudo chmod a+r /etc/apt/keyrings/docker.gpg

# Add the repository to Apt sources:
echo \
  "deb [arch="$(dpkg --print-architecture)" signed-by=/etc/apt/keyrings/docker.gpg] https://download.docker.com/linux/ubuntu \
  "$(. /etc/os-release && echo "$VERSION_CODENAME")" stable" | \
  sudo tee /etc/apt/sources.list.d/docker.list > /dev/null
sudo apt-get update

2. Install the Docker packages.

sudo apt-get install docker-ce docker-ce-cli containerd.io docker-buildx-plugin docker-compose-plugin

3. Verify that the Docker Engine installation is successful by running the hello-world image.

sudo docker run hello-world

4. Install CRID for docker
---------
4.1 Install Go
4.1.1 Download tarball 
wget https://go.dev/dl/go1.21.3.linux-amd64.tar.gz

4.1.2 untar
tar -C /usr/local -xzf go1.21.3.linux-amd64.tar.gz

4.1.3 export go path
echo 'export PATH=$PATH:/usr/local/go/bin' >>~/.profile
source ~/.profile 

4.1.4 To install, on a Linux system that uses systemd, and already has Docker Engine installed

# Clone cri-dockerd
git clone https://github.com/Mirantis/cri-dockerd.git

# with non-sudo
make cri-dockerd

# Run these commands as root

cd cri-dockerd
mkdir -p /usr/local/bin
install -o root -g root -m 0755 cri-dockerd /usr/local/bin/cri-dockerd
install packaging/systemd/* /etc/systemd/system
sed -i -e 's,/usr/bin/cri-dockerd,/usr/local/bin/cri-dockerd,' /etc/systemd/system/cri-docker.service
systemctl daemon-reload
systemctl enable --now cri-docker.socket



Installing kubeadm, kubelet and kubectl
=============

1. Update the apt package index and install packages needed to use the Kubernetes apt repository:

sudo apt-get update
# apt-transport-https may be a dummy package; if so, you can skip that package
sudo apt-get install -y apt-transport-https ca-certificates curl gpg

2. Download the public signing key for the Kubernetes package repositories. 

curl -fsSL https://pkgs.k8s.io/core:/stable:/v1.28/deb/Release.key | sudo gpg --dearmor -o /etc/apt/keyrings/kubernetes-apt-keyring.gpg


3. Add the appropriate Kubernetes apt repository
# This overwrites any existing configuration in /etc/apt/sources.list.d/kubernetes.list
echo 'deb [signed-by=/etc/apt/keyrings/kubernetes-apt-keyring.gpg] https://pkgs.k8s.io/core:/stable:/v1.28/deb/ /' | sudo tee /etc/apt/sources.list.d/kubernetes.list

4. Update the apt package index, install kubelet, kubeadm and kubectl, and pin their version:

sudo apt-get update
sudo apt-get install -y kubelet kubeadm kubectl
sudo apt-mark hold kubelet kubeadm kubectl

Creating a cluster with kubeadm
===============

sudo kubeadm init --pod-network-cidr=10.244.0.0/16 --cri-socket=unix:///var/run/cri-dockerd.sock


Your Kubernetes control-plane has initialized successfully!

To start using your cluster, you need to run the following as a regular user:

  mkdir -p $HOME/.kube
  sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
  sudo chown $(id -u):$(id -g) $HOME/.kube/config

Alternatively, if you are the root user, you can run:

  export KUBECONFIG=/etc/kubernetes/admin.conf

You should now deploy a pod network to the cluster.
Run "kubectl apply -f [podnetwork].yaml" with one of the options listed at:
  https://kubernetes.io/docs/concepts/cluster-administration/addons/

Then you can join any number of worker nodes by running the following on each as root:

sudo kubeadm join 10.131.187.176:6443 --token knefgg.pdafluamsim49olo --cri-socket=unix:///var/run/cri-dockerd.sock \
        --discovery-token-ca-cert-hash sha256:b058fc69cbec62d085bb38d84f0a89879cbe16068567f061a8fac84f87eab9aa
-----

kubectl get pods -A
NAMESPACE     NAME                                   READY   STATUS    RESTARTS   AGE
kube-system   coredns-5dd5756b68-86d94               0/1     Pending   0          5m52s
kube-system   coredns-5dd5756b68-tq4v5               0/1     Pending   0          5m52s
kube-system   etcd-k8smaster-vm                      1/1     Running   0          6m5s
kube-system   kube-apiserver-k8smaster-vm            1/1     Running   0          6m8s
kube-system   kube-controller-manager-k8smaster-vm   1/1     Running   0          6m5s
kube-system   kube-proxy-kl7d8                       1/1     Running   0          5m52s
kube-system   kube-scheduler-k8smaster-vm            1/1     Running   0          6m5s

# Install flannel
https://github.com/flannel-io/flannel#deploying-flannel-manually
kubectl apply -f https://github.com/flannel-io/flannel/releases/latest/download/kube-flannel.ym

# Check pods after installing flannel
 kubectl get pods -A --watch
NAMESPACE      NAME                                   READY   STATUS    RESTARTS   AGE
kube-flannel   kube-flannel-ds-7m5rq                  1/1     Running   0          54s
kube-system    coredns-5dd5756b68-86d94               1/1     Running   0          7m21s
kube-system    coredns-5dd5756b68-tq4v5               1/1     Running   0          7m21s
kube-system    etcd-k8smaster-vm                      1/1     Running   0          7m34s
kube-system    kube-apiserver-k8smaster-vm            1/1     Running   0          7m37s
kube-system    kube-controller-manager-k8smaster-vm   1/1     Running   0          7m34s
kube-system    kube-proxy-kl7d8                       1/1     Running   0          7m21s
kube-system    kube-scheduler-k8smaster-vm            1/1     Running   0          7m34s