https://jnaapti.com/downloads/linux-prereq.pdf
https://landscape.cncf.io/ https://jnaapti.com/downloads/visa-kubernetes.pdf
https://ericchiang.github.io/post/containers-from-scratch/ https://www.slideshare.net/jnaapti/building-your-own-desktop-cloud-environment
https://docs.docker.com/engine/install/ubuntu/
sudo apt-get update
sudo apt-get install \
apt-transport-https \
ca-certificates \
curl \
gnupg-agent \
software-properties-common
curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo apt-key add -
sudo add-apt-repository \
"deb [arch=amd64] https://download.docker.com/linux/ubuntu \
$(lsb_release -cs) \
stable"
sudo apt-get install docker-ce docker-ce-cli containerd.io
# Verification
docker --version
# Version 19.03
systemctl status docker
# Ensure that the status is "active (running)"
# You may have to press q to quit
systemctl stop docker
systemctl start docker
systemctl restart docker
# dockerd - Server
# docker - Client
sudo usermod -aG docker $USER
docker ps
docker images
https://hub.docker.com/ https://hub.docker.com/search?q=nginx&type=image https://hub.docker.com/_/nginx
docker pull nginx
docker images
docker run nginx
docker ps
ps aux | grep nginx
docker inspect <container-name>
curl 172.17.0.2
docker run -d --name webserver1 -p 80:80 nginx
docker ps
ifconfig
ifconfig eth0
<hostname>-80.cloudlab.jnaapti.io
# Stopping and starting process in the container
docker stop webserver1
# Run another container with the same image
docker run -d --name webserver2 -p 6080:80 nginx
# Create a container
docker container create <image name>
docker container create --name webserver1 nginx
# Getting help
docker container --help
# Getting logs
docker logs <container-name>
docker logs -f <container-name>
# Exec
docker exec webserver1 ls /
docker exec -it webserver1 /bin/bash
# Inside the container
echo "Hello" > /usr/share/nginx/html/index.html
^D
\
docker exec -it webserver1 /bin/bash
# Inside the container
echo "About" > /usr/share/nginx/html/about.html
rm /usr/share/nginx/html/50x.html
^D
# Commit the changes of the container webserver1 as mywebserver (image name)
docker commit webserver1 mywebserver
docker rm -f webserver2 # If webserver2 is present
docker run -d --name webserver2 mywebserver
docker inspect webserver2 | grep IP
curl <ip>
# Dockerfiles and docker build
mkdir -p ~/data/mywebserver
cd ~/data/mywebserver
cat > Dockerfile <<DELIM
FROM nginx
RUN echo "Hello" > /usr/share/nginx/html/index.html
RUN echo "About" > /usr/share/nginx/html/about.html
RUN rm /usr/share/nginx/html/50x.html
DELIM
docker build -t mywebserver .
docker images
docker image history mywebserver
# Nginx Dockerfile
https://github.com/nginxinc/docker-nginx/blob/9774b522d4661effea57a1fbf64c883e699ac3ec/mainline/buster/Dockerfile
https://github.com/debuerreotype/docker-debian-artifacts/blob/a05e37469763ce310295d7ed7529c36152bd6030/buster/slim/Dockerfile
# Networking
# Ping image
mkdir -p ~/data/ping
cd ~/data/ping
cat > Dockerfile <<DELIM
FROM ubuntu:18.04
RUN apt-get update \
&& apt-get -y install iputils-ping net-tools \
&& rm -rf /var/lib/apt/lists/*
DELIM
docker build -t ping .
docker images
# Remove existing containers
docker rm -f $(docker ps -aq)
# Let us now start 2 containers with this image
docker run -itd --name c1 ping
docker run -itd --name c2 ping
docker ps
# Ping from host to container
ping 172.17.0.2
# From container c1 to c2 and to host
docker exec -it c1 /bin/bash
# Inside the container
ping 172.17.0.3 # This is of c2
ping 172.17.0.1 # This is host
ping 8.8.8.8 # This is Internet
ping google.com # This is to show DNS resolution
docker rm -f $(docker ps -aq)
# Custom bridge network
docker network create mynet1
docker network ls
ifconfig
# Observe a network interface with the name starting with br-
docker run -itd --name c3 --net mynet1 ping
docker run -itd --name c4 --net mynet1 ping
docker inspect c3 | grep IP
docker inspect c4 | grep IP
https://docs.docker.com/network/network-tutorial-standalone/#use-user-defined-bridge-networks
https://blog.octo.com/en/how-does-it-work-docker-part-3-load-balancing-service-discovery-and-security/
# Creating a second interface
docker network create mynet2
docker network create --driver bridge --subnet 172.19.0.0/16 mynet2
docker run -itd --name c5 --net mynet2 ping
docker run -itd --name c6 --net mynet2 ping
docker network connect mynet1 c5
# Create a overlay network
docker network create --driver overlay overlay1
# Host network
docker run -it --name c7 --net host ping /bin/bash
# None network
docker run -it --name c8 --net none ping /bin/bash
# Storage, Volumes
docker rm -f $(docker ps -aq)
docker run --name webserver1 -d -v /data/webserver:/usr/share/nginx/html nginx
ls /data/webserver
curl <container-ip> # Gives 403
# Writing from host and reading inside the container
echo "Hello" > /data/webserver/index.html
# OR
echo "Hello" | sudo tee /data/webserver/index.html
curl <container-ip> # Gives the Hello page
docker exec -it webserver1 /bin/bash
# Inside the container
ls /usr/share/nginx/html/
cat /usr/share/nginx/html/index.html
# Write inside the container and read from host
echo "About" > /usr/share/nginx/html/about.html
^D
# Back in host
ls /data/webserver/
# Note that docker diff does not show these changes
docker diff webserver1
# Now remove the container
docker rm -f webserver1
# The files are still here
ls /data/webserver/
# Create a new container with the same volume mount
docker run --name webserver1 -d -v /data/webserver:/usr/share/nginx/html nginx
curl 172.17.0.2/about.html
curl 172.17.0.2
# End to End application
# Java + Spring Boot
https://github.com/buzypi/spring-jpa
# Spring Boot Application server with a MySQL database
# Images
# Database - standard mysql image - https://hub.docker.com/_/mysql
# Spring Boot Application - build your own image - Dockerfile
# Evaluate this image: https://hub.docker.com/_/maven - use jdk8 image
COPY source
RUN mvn clean install
CMD ["java", "-jar", "...jar"]
# Steps
cd ~/data
git clone https://github.com/buzypi/spring-jpa
cd spring-jpa
FROM openjdk:8
RUN apt-get update && apt-get -y install git
RUN cd /tmp \
&& git clone https://github.com/buzypi/spring-jpa \
&& cd spring-jpa \
&& ./mvnw clean install \
&& mkdir -p /srv \
&& mv target/*.jar /srv
WORKDIR /srv
CMD ["java", "-jar", "demo-0.0.1-SNAPSHOT.jar"]
docker build -t myspringapp .
https://github.com/buzypi/users-service https://github.com/buzypi/payments-service
https://github.com/buzypi/users-service-go https://github.com/buzypi/payments-service-go
https://kubernetes.io/docs/setup/production-environment/tools/kubeadm/install-kubeadm/
curl -s https://packages.cloud.google.com/apt/doc/apt-key.gpg | sudo apt-key add -
cat <<EOF | sudo tee /etc/apt/sources.list.d/kubernetes.list
deb https://apt.kubernetes.io/ kubernetes-xenial main
EOF
sudo apt-get update
sudo apt-get install -y kubelet kubeadm kubectl
sudo apt-mark hold kubelet kubeadm kubectl
https://kubernetes.io/docs/setup/production-environment/tools/kubeadm/create-cluster-kubeadm/
sudo su
kubeadm init --pod-network-cidr=10.244.0.0/16
^D
mkdir -p $HOME/.kube
sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config
kubectl get nodes
kubectl describe nodes
kubectl apply -f \
https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml
https://kubernetes.io/docs/concepts/cluster-administration/addons/#networking-and-network-policy
kubectl taint nodes $(hostname) node-role.kubernetes.io/master:NoSchedule-
# Verification
kubectl get nodes # Should say Status Ready
kubectl describe nodes | grep Taint # Should say <none>
# Uninstallation
# DO THIS ONLY IF YOUR KUBERNETES CLUSTER HAS ISSUES
kubedm reset
rm -rf /var/lib/etcd /etc/kubernetes
# Kubernetes basics
kubectl run --help
kubectl run nginx --image=nginx
# docker run --name nginx nginx
kubectl get pods
# docker ps
kubectl describe pods
# Make a note of the IP address
curl <pod-ip>
# Exec
kubectl exec -it nginx -- /bin/bash
# Inside the container
echo "Hello" > /usr/share/nginx/html/index.html
^D
# From outside the container
curl <pod-ip>
kubectl logs nginx
kubectl logs -f nginx
# Demonstration of failure handling
docker rm -f $(docker ps | grep "k8s_nginx" | awk '{print $1}')
# Delete the pod
kubectl delete pod nginx
# YAML to JSON
https://onlineyamltools.com/convert-yaml-to-json
name:
first: John
last: Doe
age: 10
present: true
emails:
- value: john@example.com
type: Personal
- value: john@example.org
type: Work
values:
-
- 10
- 20
-
- 30
- 40
description: |-
Line 1
Line 2
---
# Pod as a declarative spec
mkdir -p ~/data
cd ~/data
cat > my-first-pod.yaml <<DELIM
apiVersion: v1
kind: Pod
metadata:
name: nginx
spec:
containers:
- name: nginx
image: nginx
DELIM
kubectl delete pods --all
kubectl create -f my-first-pod.yaml
kubectl apply -f my-first-pod.yaml
apiVersion: v1
kind: Pod
metadata:
name: nginx
spec:
containers:
- name: nginx
image: nginx:alpine
kubectl apply -f my-first-pod.yaml
kubectl get pods
docker ps | grep nginx
apiVersion: v1
kind: Pod
metadata:
name: nginx
spec:
containers:
- name: nginx
image: nginx
---
apiVersion: v1
kind: Pod
metadata:
name: nginx2
spec:
containers:
- name: nginx
image: nginx
# Delete resources from the cluster - all resources mentioned in this file
kubectl delete -f my-first-pod.yaml
apiVersion: v1
kind: Pod
metadata:
name: nginx
spec:
containers:
- name: nginx
image: nginx
- name: nginx2
image: nginx
kubectl logs nginx -c nginx
kubectl logs nginx -c nginx2
apiVersion: v1
kind: Pod
metadata:
name: nginx
spec:
containers:
- name: nginx
image: nginx
- name: curl
image: curlimages/curl
stdin: true
tty: true
command: ["/bin/sh"]
kubectl apply -f my-first-pod.yaml
kubectl get pods -w
kubectl exec -it nginx -c curl -- /bin/sh
# Inside the container
ps aux
ip addr show
curl localhost
^D
# Outside the container
kubectl describe pods | grep IP
cd ~/data
cat > my-first-deployment.yaml <<DELIM
apiVersion: apps/v1
kind: Deployment
metadata:
name: nginx
spec:
replicas: 3
selector:
matchLabels:
app: nginx-app
template:
metadata:
labels:
app: nginx-app
spec:
containers:
- name: nginx
image: nginx
DELIM
kubectl delete -f my-first-pod.yaml
kubectl apply -f my-first-deployment.yaml
kubectl get deployments
kubectl get replicasets # rs
kubectl get pods
kubectl describe replicasets
# Look at the events
# Now take one of the pods from the Events and run this
kubectl describe pod <pod-name>
https://kubernetes.io/docs/concepts/overview/components/
kubectl describe deploy #deployment, deployments
apiVersion: apps/v1
kind: Deployment
metadata:
name: nginx
spec:
replicas: 5
selector:
matchLabels:
app: nginx-app
template:
metadata:
labels:
app: nginx-app
spec:
containers:
- name: nginx
image: nginx:alpine
kubectl apply -f my-first-deployment.yaml
kubectl get pods -w
kubectl describe pod <pod-name> # Use any one of the pods and check the image
kubectl describe deploy
kubectl get rs
kubectl get deployment nginx -o yaml
kubectl rollout undo deploy nginx --to-revision=1
# Getting MySQL to work
root@visa1:~# docker run --name db1 -e MYSQL_ROOT_PASSWORD=mysecretpassword -d mysql:8
Unable to find image 'mysql:8' locally
8: Pulling from library/mysql
d121f8d1c412: Already exists
f3cebc0b4691: Pull complete
1862755a0b37: Pull complete
489b44f3dbb4: Pull complete
690874f836db: Pull complete
baa8be383ffb: Pull complete
55356608b4ac: Pull complete
dd35ceccb6eb: Pull complete
429b35712b19: Pull complete
162d8291095c: Pull complete
5e500ef7181b: Pull complete
af7528e958b6: Pull complete
Digest: sha256:e1bfe11693ed2052cb3b4e5fa356c65381129e87e38551c6cd6ec532ebe0e808
Status: Downloaded newer image for mysql:8
44bbee905fb3a14b43a94bb40d2eacd790232d9e1a7bb556bf867efebcc91a32
root@visa1:~# docker ps | grep mysql
44bbee905fb3 mysql:8 "docker-entrypoint.s…" 21 seconds ago Up 20 seconds 3306/tcp, 33060/tcp db1
root@visa1:~# docker exec -it db1 mysql -uroot -p
Enter password:
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 8
Server version: 8.0.21 MySQL Community Server - GPL
Copyright (c) 2000, 2020, Oracle and/or its affiliates. All rights reserved.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
mysql> ^DBye
root@visa1:~#