Docker

Quick Start

Installation for Centos 7

https://blog.tomy168.com/2019/08/centos-76-kubernetes.html

[root@server ~]# yum install wget net-tools nano -y
[root@server ~]# hostnamectl set-hostname XXXXXX
[root@server ~]# nano /etc/hosts
[root@server ~]# setenforce 0
[root@server ~]# sed -i 's@SELINUX=enforcing@SELINUX=disabled@' /etc/sysconfig/selinux
[root@server ~]# swap -a
[root@server ~]# nano /etc/fstab
[root@server ~]# systemctl disable firewalld && systemctl stop firewalld
[root@server ~]# echo 1 > /proc/sys/net/ipv4/ip_forward
[root@server ~]# echo "net.ipv4.ip_forward = 1" >> /etc/sysctl.conf
[root@server ~]# echo "net.bridge.bridge-nf-call-iptables = 1" >> /etc/sysctl.conf
[root@server ~]# modprobe br_netfilter
[root@server ~]# echo "br_netfilter" > /etc/modules-load.d/br_netfilter.conf
[root@server ~]# sysctl -p
[root@server ~]# lsmod | grep br_netfilter
[root@server ~]# yum install -y yum-utils device-mapper-persistent-data lvm2
[root@server ~]# yum-config-manager --add-repo https://download.docker.com/linux/centos/docker-ce.repo
[root@server ~]# nano /etc/yum.repos.d/kubernetes.repo
[root@server ~]# yum clean all && yum repolist
[root@server ~]# yum install docker-ce-18.09.8 --nogpgcheck
[root@server ~]# systemctl enable docker && systemctl start docker
[root@server ~]# yum install kubelet-1.15.2 kubectl-1.15.2 kubeadm-1.15.2 --nogpgcheck --disableexcludes=kubernetes
[root@server ~]# systemctl enable kubelet.service

Basic Command

docker run -it ubuntu
docker run -itd ubuntu
docker attach <id>
docker ps
docker exec -it <id> bash

Docker Machine

docker-machine create –driver=virtualbox machine1
docker-machine ls
docker-machine ssh machine1
inside machine1 run: docker run hello-world

Restrict Memory

docker run --memory 512MB --name nginx3 -d nginx

Restrict CPU

setting cpu-quota to 25000 limits a container to 25% of CPU resource

combine with cpu-period, such as cpu-period = 100ms and cpu=quota = 200ms ~ at most use 2 cpu

1000000 (1 second) cpu-quota = 200000 => within 1 second, to use 0.2 cpu

docker run --cpu-period=1000000 --cpu-quota=500000 --name cputest2 -it cento

Adhoc Port Mapping

// find container
docker ps

// find container ip address 
docker inspect container_name | grep IPAddress

// use iptables to map local port to container port, such as 7101
iptables -t nat -A  DOCKER -p tcp --dport 7101 -j DNAT --to-destination 172.17.0.3:7101

provision jenkins through docker-compose

[origin@master jenkins-data]$ cat docker-compose.yml
version: '3'
services:
  jenkins:
    container_name: jenkins
    image: jenkins/jenkins
    ports:
      - 8080:8080
    volumes:
      - $PWD/jenkins_home:/var/jenkins_home
    networks:
      - net
  remote_host:
    container_name: remote-host
    image: remote-host
    volumes:
      - $PWD/aws-s3.sh:/tmp/script.sh
    build:
      context: centos7
    networks:
      - net
  db_host:
    container_name: db
    image: mysql:5.7
    environment:
      - MYSQL_ROOT_PASSWORD=abcd1234
    volumes:
      - $PWD/db_data:/var/lib/mysql
    networks:
      - net
networks:
  net:


$ ssh-keygen -f remote_key

[origin@master centos7]$ cat Dockerfile
FROM centos

RUN yum -y install openssh-server
RUN yum -y install openssh-clients

RUN useradd remote_user && \
    echo "1234" | passwd remote_user --stdin && \
    mkdir /home/remote_user/.ssh && \
    chmod 700 /home/remote_user/.ssh

COPY remote-key.pub /home/remote_user/.ssh/authorized_keys

RUN chown remote_user:remote_user -R /home/remote_user/.ssh/ && \
    chmod 600 /home/remote_user/.ssh/authorized_keys

RUN /usr/sbin/sshd-keygen

RUN yum -y install mysql

RUN curl -O https://bootstrap.pypa.io/get-pip.py && \
    python get-pip.py && \
    pip install awscli --upgrade


CMD /usr/sbin/sshd -D



$ ssh -i remote_key -o "StrictHostKeyChecking no" user@host

Dockerfile ENTRYPOINT vs CMD

RUN executes command(s) in a new layer and creates a new image. E.g., it is often used for installing software packages.

CMD sets default command and/or parameters, which can be overwritten from command line when docker container runs.

ENTRYPOINT configures a container that will run as an executable. <- cannot be ignore

Resources

Entry Point vs CMD

https://goinbigdata.com/docker-run-vs-cmd-vs-entrypoint/

Configure Docker project for different environments using Docker Compose 3

https://medium.com/vteam/configure-docker-project-for-different-environments-using-docker-compose-3-bfbef37d951c

Run Different Environments

https://staxmanade.com/2016/07/run-multiple-docker-environments--qa--beta--prod--from-the-same-docker-compose-file-/

Spring Boot + Build Docker Image

http://www.ityouknow.com/springboot/2018/03/19/spring-boot-docker.html

Spring Boot + Build Docker Image Sample Project

https://github.com/carnellj/spmia-chapter1

MSSQL on docker

https://dotblogs.com.tw/swater111/2017/01/16/183653

Docker Introduction

https://philipzheng.gitbooks.io/docker_practice/content/data_management/volume.html

Docker學習筆記

https://peihsinsu.gitbooks.io/docker-note-book/docker-save-image.html

Get Docker for Windows

https://store.docker.com/editions/community/docker-ce-desktop-windows

Introduction and Tutorials

https://github.com/twtrubiks/docker-tutorial

Docker Command

http://www.runoob.com/docker/docker-exec-command.html

Docker Jenkins example

https://oomusou.io/docker/jenkins/

Install Java 8

https://www.atlassian.com/blog/software-teams/deploy-java-apps-with-docker-awesome

Install Docker in Linux (Bash Command Line History) for Redhat 7.5

  348  yum install docker
  349  docker
  350  sudo yum-config-manager --add-repo https://download.docker.com/linux/centos/docker-ce.repo
  351  yum install docker-ce
  352  yum install docker
  353  sudo yum remove docker docker-common docker-selinux docker-engine-selinux docker-engine docker-ce
  355  sudo yum-config-manager --add-repo https://download.docker.com/linux/centos/docker-ce.repo
  356  sudo yum install docker-ce
  359  sudo yum -y install docker-ce
  360  sudo yum erase docker-engine-selinux
  361  yum install -y --setopt=obsoletes=0   docker-ce-18.03.1.ce-1.el7.centos   docker-ce-selinux-18.03.1.ce-1.el7.centos
  362  yum install docker-ce-selinux-17.03.1.ce-1.el7.centos
  363  yum install docker-ce-selinux-18.03.1.ce-1.el7.centos
  364   yum install -y --setopt=obsoletes=0   docker-ce-17.03.1.ce-1.el7.centos   docker-ce-selinux-17.03.1.ce-1.el7.centos
  365  docker
  367  docker run hello-world
  368  service docker start
  369  docker run hello-world
  371  docker run hello-world