Docker 笔记

本文记录了学习Docker过程中安装、常用命令、理解等，整理自官网、慕课网视频。

Install In Centos

Update docker in centos from 1.13.1 to 18.03.0-ce:

sudo yum remove docker \
                  docker-client \
                  docker-client-latest \
                  docker-common \
                  docker-latest \
                  docker-latest-logrotate \
                  docker-logrotate \
                  docker-selinux \
                  docker-engine-selinux \
                  docker-engine
yum list docker-ce --showduplicates | sort -r
yum install docker-ce18.03.0.ce-1.el7.centos
// If "Unable to install docker docker-ce18.03.0.ce-1.el7.centos", run command below
yum install -y --setopt=obsoletes=0 \
  docker-ce-18.03.0.ce-1.el7.centos \
  docker-ce-selinux-18.03.0.ce-1.el7.centos
  
docker -v

1
2
3

// If "options: used when "-bash: warning: setlocale: LC_CTYPE: cannot change locale (UTF-8): No such file or directory"
# echo "export LC_ALL=en_US.UTF-8"  >>  /etc/pro  
// logout and login again

Start

1	systemctl start docker

Introduction

Docker 架构

docker run [Image] -> container

Dockerfile -> docker build -t [Image-name] -> Images

docker-compose.yml -> docker-composer up -> container
    |-> docker swarm init
    |-> docker stack deploy -c docker-compose.yml getstartedlab 
    |-> service (docker stack ps getstartedlab)

software containerization
解决问题：
1、运行环境（系统，jdk，代码）不一致导致的不能运行
2、隔离性
3、快速扩展

Docker Image

Docker Images are shared, can be copyed to the container but only readable

docker pull hello-world
// list
docker images
// rm
docker rmi <imagename>            # Remove the specified image from this machine
docker rmi $(docker images -q)             # Remove all images from this machine

docker 原理

Docker Container

The same Image will be copied to different container.

docker run hello-world
docker run --help

docker ps                                 # See a list of all running containers
docker stop <hash>                     # Gracefully stop the specified container
docker kill <hash>                   # Force shutdown of the specified container

docker exec --help
            -i  Keep STDIN open even if not attached
            -t  Allocate a pseudo-TTY
            
docker exec -it f4 bash
            (enter docker exec)
            ls
            ps -ef
            exit

docker ps -a           # See a list of all containers, even the ones not running
docker container start [containerID]
docker rm <hash>              # Remove the specified container from this machine
docker rm $(docker ps -a -q)           # Remove all containers from this machine

The difference between docker stop and docker rm

Docker Warehouse

hub.docker.com (default)
c.163.com

// China Warehouse Linux
vim /etc/default/docker
DOCKER_OPTS="--registry-mirror=https://registry.docker-cn.com"

China Warehouse Mac:

Docker Pull

pull image from warehouse

1	docker pull hello-world

Docker Run

copy image to container
if the image is not exist, ‘docker pull’ firstly

1	docker run hello-world

Docker run Nginx

docker pull hub.c.163.com/library/nginx:latest

docker run --help
            -d, --detach Run container in background and print container
            
docker run -d hub.c.163.com/library/nginx
            f4e......
            
docker ps  
            (print containers has runed.)
            
docker exec --help
            -i  Keep STDIN open even if not attached
            -t  Allocate a pseudo-TTY
            
docker exec -it f4 bash
            (enter docker exec)
            ls
            ps -ef
            exit
            
docker stop f4

Docker Nginx Network

host链接方式是直接链接主机网卡
bridge需要链接一个网桥bridge，然后通过网桥链接主机，container有自己独立等ip和端口

docker run --help
            -p  Publish a container's port(s) to the host (default)                 
            -P  Publish all exposed ports to random ports
docker run -d -p 8080:80 hub.c.163.com/library/nginx
                (Host:Container)
docker ps
nestat -na|grep 32769

Dockerfile

Define a container with a Dockerfile

docker build -t friendlyname .  # Create image using this directory's Dockerfile
docker run -p 4000:80 friendlyname  # Run "friendlyname" mapping port 4000 to 80
docker run -d -p 4000:80 friendlyname         # Same thing, but in detached mode
docker ps                                 # See a list of all running containers
docker stop <hash>                     # Gracefully stop the specified container
docker ps -a           # See a list of all containers, even the ones not running
docker kill <hash>                   # Force shutdown of the specified container
docker rm <hash>              # Remove the specified container from this machine
docker rm $(docker ps -a -q)           # Remove all containers from this machine
docker images -a                               # Show all images on this machine
docker rmi <imagename>            # Remove the specified image from this machine
docker rmi $(docker images -q)             # Remove all images from this machine
docker login             # Log in this CLI session using your Docker credentials
docker tag <image> username/repository:tag  # Tag <image> for upload to registry
docker push username/repository:tag            # Upload tagged image to registry
docker run username/repository:tag                   # Run image from a registry

Docker compose

docker-compose up -d         # start containers in background
docker-compose kill          # stop containers
docker-compose up -d --build # force rebuild of Dockerfiles
docker-compose rm            # remove stopped containers
docker ps                    # see list of running containers
docker exec -ti [NAME] bash

Services (containers in production)

https://docs.docker.com/get-started/part3/#understanding-services

docker stack ls              # List all running applications on this Docker host
docker stack deploy -c <composefile> <appname>  # Run the specified Compose file
docker stack services <appname>       # List the services associated with an app
docker stack ps <appname>   # List the running containers associated with an app
docker stack rm <appname>                             # Tear down an application

Swarms/Stacks

A swarm is a group of machines that are running Docker and joined into a cluster
A single stack is capable of defining and coordinating the functionality of an entire application (though very complex applications may want to use multiple stacks).

https://docs.docker.com/get-started/part4/#set-up-your-swarm
https://docs.docker.com/get-started/part5/stacks

network

1 2	docker network inspect bridge docker network disconnect bridge [Containers: Name]

Install in centos

Get Docker CE for CentOS | docker official

Tip: replacing $ sudo yum install docker-ce with $ sudo yum install docker will be faster
Install Docker Compose | docker official

// step 1: 在Docker中打开Preferences, 点击File Sharing将其它目录全部删掉只保留/tmp目录

// step 2: 克隆 d4m-nfs 到 ~目录下
$ cd ~
$ git clone https://github.com/IFSight/d4m-nfs ~/d4m-nfs

// step 3: 项目克隆下来后修改~/d4m-nfs/etc/d4m-nfs-mounts.txt文件
$ vim ~/d4m-nfs/etc/d4m-nfs-mounts.txt
    /Users:/Users
    /Volumes:/Volumes
    /private:/private
    
// step 4 检查系统文件 /etc/exports下是否有内容，编辑文件清空所有内容!(rm)
$ cat /etc/exports
$ sudo rm -rf /etc/exports

// step 5
$ ~/d4m-nfs/d4m-nfs.sh

// success
$ screen -r d4m