weekly42

Makefile, kubernetes, cluster, docker, 2021.05

• Rethinking some tools:

• Docker - container

• Kubernetes - nodes, services

• OpenFaas - Funciton as a Service - time limitless

• K3d - cluster

• TSL - cert-manager

• kubernetes/Vagrantfile

---

Kubebernetes local cluster

• Kubebernetes local cluster, create with kubeadm, kubectl, kubelet
• Running in debian host, three debian, kmaster.local, kworker1, kworker2
• Using vagrant as a provisioner of this Infraestructure

# -*- mode: ruby -*-
# vi: set ft=ruby :
Vagrant.configure("2") do |config|
  config.vm.provision "shell", path: "bootstrap.sh"
  # Kubernetes Master Server
  config.vm.define "kmaster" do |node|
    node.vm.box               = "debian/buster64"
    node.vm.hostname          = "kmaster.local"
    node.vm.network "private_network", ip: "172.16.16.100"
    node.vm.provider :virtualbox do |v|
      v.name    = "kmaster"
      v.memory  = 2048
    end
    node.vm.provision "shell", path: "bootstrap_kmaster.sh"
  end
  # Kubernetes Worker Nodes
  NodeCount = 2
  (1..NodeCount).each do |i|
    config.vm.define "kworker#{i}" do |node|
      node.vm.box               = "debian/buster64"
      node.vm.hostname          = "kworker#{i}.local"
      node.vm.network "private_network", ip: "172.16.16.10#{i}"
      node.vm.provider :virtualbox do |v|
        v.name    = "kworker#{i}"
        v.memory  = 1024
        v.cpus    = 1
      end
     node.vm.provision "shell", path: "bootstrap_kworker.sh"
    end
  end
end

• kubernetes/bootstrap.sh

#!/bin/bash

echo "[TASK 1] Disable and turn off SWAP"
sed -i '/swap/d' /etc/fstab
swapoff -a

echo "[TASK 2] Stop and Disable firewall"
systemctl disable --now ufw >/dev/null 2>&1

echo "[TASK 3] Enable and Load Kernel modules"
mkdir /etc/docker
cat <<EOF | tee /etc/docker/daemon.json
{
  "exec-opts": ["native.cgroupdriver=systemd"],
  "log-driver": "json-file",
  "log-opts": {
    "max-size": "100m"
  },
  "storage-driver": "overlay2"
}
EOF

echo "[TASK 4] Add Kernel settings"
cat >>/etc/sysctl.d/kubernetes.conf<<EOF
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables  = 1
net.ipv4.ip_forward                 = 1
EOF
sysctl --system >/dev/null 2>&1

echo "[TASK 5] Install containerd runtime"
apt-get -y update -qq >/dev/null 2>&1
apt-get -y -qq remove docker docker-engine docker.io runc >/dev/null 2>&1
apt-get -y -qq install apt-transport-https software-properties-common ca-certificates curl gnupg lsb-release; echo  'deb [arch=amd64] https://download.docker.com/linux/debian  buster stable' | tee /etc/apt/sources.list.d/docker.list > /dev/null ;  curl -fsSL https://download.docker.com/linux/debian/gpg | apt-key add - ; add-apt-repository "deb [arch=amd64] https://download.docker.com/linux/debian buster stable" ; apt-get -y -qq update; apt-get -y -qq remove docker docker-engine docker.io runc; apt-get -y -qq install docker-ce docker-ce-cli containerd.io; usermod -aG docker vagrant >/dev/null 2>&1
systemctl enable docker >/dev/null 2>&1
systemctl daemon-reload >/dev/null 2>&1
systemctl restart docker >/dev/null 2>&1

echo "[TASK 6] Add apt repo for kubernetes"
curl -s https://packages.cloud.google.com/apt/doc/apt-key.gpg | apt-key add - >/dev/null 2>&1
apt-add-repository "deb http://apt.kubernetes.io/ kubernetes-xenial main" >/dev/null 2>&1
apt-get -y update -qq >/dev/null 2>&1

echo "[TASK 7] Install Kubernetes components (kubeadm, kubelet and kubectl)"
apt-get install -qq -y kubeadm kubelet kubectl >/dev/null 2>&1

echo "[TASK 8] Enable ssh password authentication"
sed -i 's/^PasswordAuthentication .*/PasswordAuthentication yes/' /etc/ssh/sshd_config
echo 'PermitRootLogin yes' >> /etc/ssh/sshd_config
systemctl reload sshd

echo "[TASK 9] Set root password"
echo -e "kubeadmin\nkubeadmin" | passwd root >/dev/null 2>&1
echo "export TERM=xterm" >> /etc/bash.bashrc

echo "[TASK 10] Update /etc/hosts file"
cat >>/etc/hosts<<EOF
172.16.16.100   kmaster.local     kmaster
172.16.16.101   kworker1.local    kworker1
172.16.16.102   kworker2.local    kworker2
EOF

• kubernetes/bootstrap_kmaster.sh

#!/bin/bash

echo "[TASK 1] Pull required containers"
kubeadm config images pull >/dev/null 2>&1

echo "[TASK 2] Initialize Kubernetes Cluster"
kubeadm init --apiserver-advertise-address=172.16.16.100 --pod-network-cidr=192.168.0.0/16 >> /root/kubeinit.log 2>/dev/null

echo "[TASK 3] Deploy Calico network"
kubectl --kubeconfig=/etc/kubernetes/admin.conf create -f https://docs.projectcalico.org/v3.18/manifests/calico.yaml >/dev/null 2>&1

echo "[TASK 4] Generate and save cluster join command to /joincluster.sh"
kubeadm token create --print-join-command > /joincluster.sh 2>/dev/null

• kubernetes/bootstrap_kworker.sh

#!/bin/bash

echo "[TASK 1] Join node to Kubernetes Cluster"
apt-get install -qq -y sshpass >/dev/null 2>&1
sshpass -p "kubeadmin" scp -o UserKnownHostsFile=/dev/null -o StrictHostKeyChecking=no kmaster.local:/joincluster.sh /joincluster.sh 2>/dev/null
bash /joincluster.sh >/dev/null 2>&1

---

---

---

React Typescript notes

• app/src/App.tsx

import React, { useState } from 'react';
import './App.css';
import AddToList from './comp/AddToList';
import List from './comp/List';

export interface IState {
  people: {
    name: string,
    height: number,
    url: string,
    note?: string 
  }[]
}

function App() {

  const [people, setPeople] = useState<IState["people"]>([{
    name: 'Donald Knuth',
    height: 197,
    url: '',
    note: 'The Art of Computer Programming'
  }]);
  return (
    <div className="App">
      <h1>People</h1>
      <List people={people} />
      <AddToList people={people} setPeople={setPeople}/>
    </div>
  );
}
export default App;

• app/src/comp/List.tsx

import React from 'react';
import { IState as IProps} from '../App';


const List: React.FC<IProps> = ({ people }) => {
  const renderList = (): JSX.Element[] => {
    return people.map( (person) => {
      return (
        <li>
          <article className='List'>
            <header className='List-header'>
              <img className='List-img' src={person.url} />
              <h2>{person.name}</h2></header>
            <p className='List-note'>{person.note}</p>
          </article>
        </li>
      )
    })
  }
  
  return (
    <ul>
      {renderList()}
    </ul>
  )
}

export default List

• app/src/comp/AddToList.tsx

import React, { useState } from 'react';
import { IState as Props} from '../App';

interface IProps{
  people: Props["people"],
  setPeople: React.Dispatch<React.SetStateAction<Props["people"]>>
}

const AddToList: React.FC<IProps> = ({people, setPeople}) => {

  const [input, setInput] = useState({
    name: '',
    height: '',
    img: '',
    note: '',
  });

  const handleChange = (e: React.ChangeEvent<HTMLInputElement | HTMLTextAreaElement>): void => {
    setInput({
      ...input,
      [e.target.name]: e.target.value
    })
  }

  const handleClick = (): void => {
    if( !input.name || !input.height || !input.img ){
      return;
    }
    setPeople([
      ...people,
      {
        name: input.name,
        height: parseInt(input.height),
        url: input.img,
        note: input.note
      }
    ]);
    setInput({
      name: '',
      height: '',
      img: '',
      note: ''
      });
  }

  return (
    <div className='AddToList'>
      <input type='text' placeholder='Name'
            className='AddToList-input'
            value={input.name}
            onChange={handleChange}
            name='name'
      /> 
      <input type='number' placeholder='Height'
            className='AddToList-input'
            value={input.height}
            onChange={handleChange}
            name='height'
      />  
      <input type='text' placeholder='Image URL'
            className='AddToList-input'
            value={input.img}
            onChange={handleChange}
            name='img'
      />  
      <textarea placeholder='Note'
            className='AddToList-input'
            value={input.note}
            onChange={handleChange}
            name='note'
      />  
      <button className='AddToList-btn'
        onClick={handleClick}
      >Add To List</button>
    </div>
  )
}

export default AddToList;