session12sl.txt

Create Docker Compose file and Install Docker compose
sudo apt update
sudo apt install docker-compose

#Create a file docker-compose.yml
version: '2'
services:
  compose-test:
     image: centos
     links:
       - compose-db
     command: /usr/bin/curl compose-db:6379
  compose-db:
    image: redis
    expose:
      - "6379"


#make sure docker is working
#to check the same 
systemctl status docker
systemctl restart docker

# if it fails then create the daemonfile in the below path
nano /etc/docker/daemon.json
{
  "exec-opts": ["native.cgroupdriver=systemd"]
}
or you can also follow below stackoverflow link
https://stackoverflow.com/questions/49110092/failed-to-start-docker-application-container-engine

#and then restart the docker 
systemctl restart docker
+++++++++++++++++++++++++++++++

#run the docker comppose up command to upload
sudo docker-compose up


+++++++++++++++++++++++++++++++++++++
1.Public container Registry .2. Private registry (ecr,acr,ghcr)




#Upload a docker image to dockerhub public container registry

#retag the image
docker tag <imagenameid> <dockerhubusername>/<imagename>:tag
docker tag 5d0da3dc9764 niladrimondaldcr/niladricentos:2.0

#retag or create the docker image with below format

<dockerhubusername>/<imagename>:tag
niladrimondaldcr/niladricentos:2.0

#push the image to the dockerhub registry

Login to the docker
root@ip-172-31-25-250:/home/shialmonstar199# docker login
Login with your Docker ID to push and pull images from Docker Hub. If you don't have a Docker ID, head over to https://hub.docker.com to create one.
Username: niladrimondaldcr
Password: 
WARNING! Your password will be stored unencrypted in /root/.docker/config.json.
Configure a credential helper to remove this warning. See
https://docs.docker.com/engine/reference/commandline/login/#credentials-store

Login Succeeded
root@ip-172-31-25-250:/home/shialmonstar199# 

#docker push command
docker push niladrimondaldcr/niladricentos:2.0

root@ip-172-31-25-250:/home/shialmonstar199# docker push niladrimondaldcr/niladricentos:2.0
The push refers to repository [docker.io/niladrimondaldcr/niladricentos]
74ddd0ec08fa: Mounted from library/centos 
2.0: digest: sha256:a1801b843b1bfaf77c501e7a6d3f709401a1e0c83863037fa3aab063a7fdb9dc size: 529



#Upload the image into the private repository

#Pull the docker registry:2 image
root@ip-172-31-25-250:/home/shialmonstar199# docker pull registry:2
2: Pulling from library/registry
ca7dd9ec2225: Pull complete 
c41ae7ad2b39: Pull complete 
1ed0fc8a6161: Pull complete 
21df229223d2: Pull complete 
626897ccab21: Pull complete 
Digest: sha256:ce14a6258f37702ff3cd92232a6f5b81ace542d9f1631966999e9f7c1ee6ddba
Status: Downloaded newer image for registry:2
docker.io/library/registry:2
root@ip-172-31-25-250:/home/shialmonstar199# docker images
REPOSITORY                       TAG       IMAGE ID       CREATED         SIZE
redis                            latest    2f66aad5324a   47 hours ago    117MB
registry                         2         81c944c2288b   3 months ago    24.1MB
centos                           latest    5d0da3dc9764   17 months ago   231MB
niladrimondaldcr/niladricentos   2.0       5d0da3dc9764   17 months ago   231MB
root@ip-172-31-25-250:/home/shialmonstar199# 

#Run a container with registry:2 image
docker run -d -p 5000:5000 --restart=always --name registry registry:2

#i can access the private repository from the localhost rdp
http://localhost:5000/v2/_catalog

#retage the image to push
root@ip-172-31-25-250:~# docker tag 5d0da3dc9764 localhost:5000/niladricentos:2.0

#docker psuh
docker push localhost:5000/niladricentos:2.0

#now browse again to the private repo
http://localhost:5000/v2/_catalog

#Cleanup
docker rm -f $(docker ps -aq)
docker rmi -f $(docker images -q)
++++++++++++++++++++++++++++++++++++++++

Kubernetes:

1. Master 
   
    kube-scheduler
	etcd (database)    (etcd-replica in another region multiple copy)
    controller manager
	  node controller
	  replicas controler
	apiserver

2.worker nodes
    kubelet
	kube-proxy
	pod
	docker runtime