简介  这篇文章主要介绍了Docker&K8s---Docker的安装、部署、镜像管理、容器操作、Dockerfile以及相关的经验技巧，文章约54164字，浏览量284，点赞数9，值得推荐！

Docker&K8s—Docker的安装、部署、镜像管理、容器操作、Dockerfile

容器概述

容器是一种基础工具。泛指任何可以用于容纳其它物品的工具，可以部分或完全封闭，被用于容纳、存储、运输物品。物体可以被放置在容器中，而容器则可以保护内容物。

​ — 维基百科

 

避免进程之间的可能的影响，我们分别把不同环境的进程再不同的容器种运行。在同一台宿主机但又相互隔离—虚拟化技术，类似于装虚拟机，然后在系统上装虚拟机上装操作系统，再装环境。这样太麻烦，容器技术相应出现—直接在系统安装Dockers Engine并在其上安装环境。

满足隔离条件：

image-20210616171712409

 

容器发展历程

image-20210616172111795

Docker简介

2013年Docker正式发布，早在2010年，几个大胡子就在旧金山成立了一家Paas平台的公司—dotCloud。2013 年 3 月，dotCloud 公司的创始人之一，Docker 之父，28 岁的 Solomon Hykes 正式决定，将 Docker 项目开源。

img

Build Once, Run Anywhere.

​ —Solomon Hykes

  • Docker基于容器技术的轻量级虚拟化解决方案
  • Docker是容器引擎，为用户提供了创建和管理容器的便捷界面（包括命令行和API）
  • 开源，基于Go语言实现
  • 大部分厂商都支持
  • 整套的容器管理的生态系统

image-20210616174308165

Docker引擎主要有两个版本：企业版（EE）和社区版（CE）。

Docker安装和部署

安装

阿里云ECS

[root@iZuf6g4e6vhdv58sz2z1klZ ~]# uname -a
Linux iZuf6g4e6vhdv58sz2z1klZ 4.18.0-193.28.1.el8_2.x86_64 #1 SMP Thu Oct 22 00:20:22 UTC 2020 x86_64 x86_64 x
[root@iZuf6g4e6vhdv58sz2z1klZ ~]# cat /etc/redhat-release 
CentOS Linux release 8.2.2004 (Core) 
[root@iZuf6g4e6vhdv58sz2z1klZ ~]# getenforce 
Disabled
[root@iZuf6g4e6vhdv58sz2z1klZ ~]# systemctl stop firewalld
[root@iZuf6g4e6vhdv58sz2z1klZ ~]# free -m
              total        used        free      shared  buff/cache   available
Mem:           1723        1115         139           3         468         440
Swap:          1024         301         723
# epel源
[root@iZuf6g4e6vhdv58sz2z1klZ ~]# yum install epel-release -y
Repository epel is listed more than once in the configuration
Last metadata expiration check: 2:47:33 ago on Wed 16 Jun 2021 03:07:22 PM CST.
Package epel-release-8-10.el8.noarch is already installed.
Dependencies resolved.
Nothing to do.
Complete!


# 安装docker
[root@iZuf6g4e6vhdv58sz2z1klZ ~]# yum install -y yum-utils
[root@iZuf6g4e6vhdv58sz2z1klZ ~]# yum-config-manager --add-repo http://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo
[root@iZuf6g4e6vhdv58sz2z1klZ ~]# yum list docker-ce --showduplicate
Repository epel is listed more than once in the configuration
Docker CE Stable - x86_64                                                     78 kB/s |  14 kB     00:00    
Available Packages
docker-ce.x86_64                              3:19.03.13-3.el8                               docker-ce-stable
docker-ce.x86_64                              3:19.03.14-3.el8                               docker-ce-stable
docker-ce.x86_64                              3:19.03.15-3.el8                               docker-ce-stable
docker-ce.x86_64                              3:20.10.0-3.el8                                docker-ce-stable
docker-ce.x86_64                              3:20.10.1-3.el8                                docker-ce-stable
docker-ce.x86_64                              3:20.10.2-3.el8                                docker-ce-stable
docker-ce.x86_64                              3:20.10.3-3.el8                                docker-ce-stable
docker-ce.x86_64                              3:20.10.4-3.el8                                docker-ce-stable
docker-ce.x86_64                              3:20.10.5-3.el8                                docker-ce-stable
docker-ce.x86_64                              3:20.10.6-3.el8                                docker-ce-stable
docker-ce.x86_64                              3:20.10.7-3.el8                                docker-ce-stable
[root@iZuf6g4e6vhdv58sz2z1klZ ~]# yum install docker-ce -y

部署

# 开机自启动
[root@iZuf6g4e6vhdv58sz2z1klZ ~]# systemctl enable docker
Created symlink /etc/systemd/system/multi-user.target.wants/docker.service → /usr/lib/systemd/system/docker.service.
# 启动docker
[root@iZuf6g4e6vhdv58sz2z1klZ ~]# systemctl start docker
# 配置
[root@iZuf6g4e6vhdv58sz2z1klZ ~]#vi /etc/docker/daemon.json

配置文件

{
	"graph": "/mydata/docker",
	"storage-driver": "overlay2",
	"insecure-registries": ["registry.access.redhat.com", "quay.io"],
	"registry-mirrors": ["https://q2gr04ke.mirror.aliyuncs.com/"],
    "bip": "172.17.0.1/24",
    "exec-opts": ["native.cgroupdriver=systemd"],
    "live-restore":true
}

docker info

查看容器信息和启动是否正常

[root@iZuf6g4e6vhdv58sz2z1klZ ~]# systemctl restart docker
[root@iZuf6g4e6vhdv58sz2z1klZ ~]# docker info
Client:
 Context:    default
 Debug Mode: false
 Plugins:
  app: Docker App (Docker Inc., v0.9.1-beta3)
  buildx: Build with BuildKit (Docker Inc., v0.5.1-docker)
  scan: Docker Scan (Docker Inc., v0.8.0)

Server:
 Containers: 0
  Running: 0
  Paused: 0
  Stopped: 0
 Images: 0
 Server Version: 20.10.7
 Storage Driver: overlay2
  Backing Filesystem: xfs
  Supports d_type: true
  Native Overlay Diff: true
  userxattr: false
 Logging Driver: json-file
 Cgroup Driver: systemd
 Cgroup Version: 1
 Plugins:
  Volume: local
  Network: bridge host ipvlan macvlan null overlay
  Log: awslogs fluentd gcplogs gelf journald json-file local logentries splunk syslog
 Swarm: inactive
 Runtimes: io.containerd.runc.v2 io.containerd.runtime.v1.linux runc
 Default Runtime: runc
 Init Binary: docker-init
 containerd version: d71fcd7d8303cbf684402823e425e9dd2e99285d
 runc version: b9ee9c6314599f1b4a7f497e1f1f856fe433d3b7
 init version: de40ad0
 Security Options:
  seccomp
   Profile: default
 Kernel Version: 4.18.0-193.28.1.el8_2.x86_64
 Operating System: CentOS Linux 8 (Core)
 OSType: linux
 Architecture: x86_64
 CPUs: 2
 Total Memory: 1.683GiB
 Name: iZuf6g4e6vhdv58sz2z1klZ
 ID: T3TJ:BJTA:U5PY:ZX74:K57G:7CDR:RMCT:CSBG:JLFG:FXPQ:KUB6:MVJT
 Docker Root Dir: /mydata/docker
 Debug Mode: false
 Registry: https://index.docker.io/v1/
 Labels:
 Experimental: false
 Insecure Registries:
  quay.io
  registry.access.redhat.com
  127.0.0.0/8
 Registry Mirrors:
  https://q2gr04ke.mirror.aliyuncs.com/
 Live Restore Enabled: true

第一个命令hello world

[root@iZuf6g4e6vhdv58sz2z1klZ ~]# docker run hello-world
Unable to find image 'hello-world:latest' locally
latest: Pulling from library/hello-world
b8dfde127a29: Pull complete 
Digest: sha256:9f6ad537c5132bcce57f7a0a20e317228d382c3cd61edae14650eec68b2b345c
Status: Downloaded newer image for hello-world:latest

Hello from Docker!
This message shows that your installation appears to be working correctly.

To generate this message, Docker took the following steps:
 1. The Docker client contacted the Docker daemon.
 2. The Docker daemon pulled the "hello-world" image from the Docker Hub.
    (amd64)
 3. The Docker daemon created a new container from that image which runs the
    executable that produces the output you are currently reading.
 4. The Docker daemon streamed that output to the Docker client, which sent it
    to your terminal.

To try something more ambitious, you can run an Ubuntu container with:
 $ docker run -it ubuntu bash

Share images, automate workflows, and more with a free Docker ID:
 https://hub.docker.com/

For more examples and ideas, visit:
 https://docs.docker.com/get-started/

Docker典型的C/S架构引擎

To generate this message, Docker took the following steps:

  1. The Docker client contacted the Docker daemon.
  2. The Docker daemon pulled the “hello-world” image from the Docker Hub.
    (amd64)
  3. The Docker daemon created a new container from that image which runs the
    executable that produces the output you are currently reading.
  4. The Docker daemon streamed that output to the Docker client, which sent it
    to your terminal.

image-20210616193445804

Docker的镜像管理

远端仓库

注册dockerhub: https://hub.docker.com/repositories

登录: docker login docker.io

[root@iZuf6g4e6vhdv58sz2z1klZ ~]# docker login docker.io
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: dachongming
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@iZuf6g4e6vhdv58sz2z1klZ ~]# 
# 信息存储在
[root@iZuf6g4e6vhdv58sz2z1klZ ~]# cat /root/.docker/config.json

搜索镜像

docker search alpine

[root@iZuf6g4e6vhdv58sz2z1klZ ~]# docker search alpine
NAME                                   DESCRIPTION                                     STARS     OFFICIAL   AUTOMATED
alpine                                 A minimal Docker image based on Alpine Linux…   7551      [OK]       
mhart/alpine-node                      Minimal Node.js built on Alpine Linux           484                  
anapsix/alpine-java                    Oracle Java 8 (and 7) with GLIBC 2.28 over A…   470                  [OK]
frolvlad/alpine-glibc                  Alpine Docker image with glibc (~12MB)          261                  [OK]
alpine/git                             A  simple git container running in alpine li…   183                  [OK]
yobasystems/alpine-mariadb             MariaDB running on Alpine Linux [docker] [am…   89                   [OK]
alpine/socat                           Run socat command in alpine container           68                   [OK]
davidcaste/alpine-tomcat               Apache Tomcat 7/8 using Oracle Java 7/8 with…   44                   [OK]
kiasaki/alpine-postgres                PostgreSQL docker image based on Alpine Linux   44                   [OK]
jfloff/alpine-python                   A small, more complete, Python Docker image …   41                   [OK]
byrnedo/alpine-curl                    Alpine linux with curl installed and set as …   34                   [OK]
zenika/alpine-chrome                   Chrome running in headless mode in a tiny Al…   34                   [OK]
hermsi/alpine-sshd                     Dockerize your OpenSSH-server with rsync and…   33                   [OK]
hermsi/alpine-fpm-php                  FPM-PHP 7.0 to 8.0, shipped along with tons …   25                   [OK]
etopian/alpine-php-wordpress           Alpine WordPress Nginx PHP-FPM WP-CLI           25                   [OK]
bashell/alpine-bash                    Alpine Linux with /bin/bash as a default she…   18                   [OK]
davidcaste/alpine-java-unlimited-jce   Oracle Java 8 (and 7) with GLIBC 2.21 over A…   13                   [OK]
roribio16/alpine-sqs                   Dockerized ElasticMQ server + web UI over Al…   13                   [OK]
spotify/alpine                         Alpine image with `bash` and `curl`.            11                   [OK]
cfmanteiga/alpine-bash-curl-jq         Docker Alpine image with Bash, curl and jq p…   6                    [OK]
bushrangers/alpine-caddy               Alpine Linux Docker Container running Caddys…   1                    [OK]
ellerbrock/alpine-mysql-client         MySQL Client based on Alpine Linux              1                    [OK]
apteno/alpine-jq                       Weekly build of alpine image with curl, wget…   1                    
dwdraju/alpine-curl-jq                 Alpine Docker Image with curl, jq, bash         1                    [OK]
goodguykoi/alpine-curl-internal        simple alpine image with curl installed no C…   1                    [OK]

也可在dockerhub上搜索,有可视化界面

image-20210616194924659

下载一个镜像

docker pull alpine

docker pull alpine 默认下载最新版

docker pull alpine:3.10.1 下载指定tag

docker pull docker.io/library/alpine:3.10.1 完整路径,其他仓库不可省,只有dockerhub可省

镜像结构: registry_name/repository_name/image_name:tag_name

例如:docker.io/library/alpine:3.10.1

[root@iZuf6g4e6vhdv58sz2z1klZ ~]# docker pull alpine
Using default tag: latest
latest: Pulling from library/alpine
5843afab3874: Pull complete 
Digest: sha256:234cb88d3020898631af0ccbbcca9a66ae7306ecd30c9720690858c1b007d2a0
Status: Downloaded newer image for alpine:latest
docker.io/library/alpine:latest

查看本地镜像

docker image ls

[root@iZuf6g4e6vhdv58sz2z1klZ ~]# docker image ls
REPOSITORY    TAG       IMAGE ID       CREATED        SIZE
alpine        latest    d4ff818577bc   14 hours ago   5.6MB
hello-world   latest    d1165f221234   3 months ago   13.3kB

给镜像打标签

docker tag IMAGE ID registry_name/repository_name/image_name:tag_name

[root@iZuf6g4e6vhdv58sz2z1klZ ~]# docker tag d4ff818577bc docker.io/dachongming/alpine:v3.14.0
[root@iZuf6g4e6vhdv58sz2z1klZ ~]# docker image ls
REPOSITORY           TAG       IMAGE ID       CREATED        SIZE
dachongming/alpine   v3.14.0   d4ff818577bc   14 hours ago   5.6MB
alpine               latest    d4ff818577bc   14 hours ago   5.6MB
hello-world          latest    d1165f221234   3 months ago   13.3kB

推送镜像

docker push docker.io/dachongming/alpine:v3.14.0

[root@iZuf6g4e6vhdv58sz2z1klZ ~]# docker push docker.io/dachongming/alpine:v3.14.0
The push refers to repository [docker.io/dachongming/alpine]
72e830a4dff5: Mounted from library/alpine 
v3.14.0: digest: sha256:1775bebec23e1f3ce486989bfc9ff3c4e951690df84aa9f926497d82f2ffca9d size: 528

image-20210616200348640

删除镜像

docker rmi docker.io/dachongming/alpine:v3.14.0

只是删除标签

docker rmi -f IMAGE ID

强制删除所有

docker hub 上依然存在,想再有,直接pull即可

image-20210616201442276

镜像只第一次拉取比较多,以后每次只拉取增量部分.

Docker容器的基本操作

查看本地的容器进程

docker ps -a

[root@iZuf6g4e6vhdv58sz2z1klZ ~]# docker ps -a
CONTAINER ID   IMAGE         COMMAND    CREATED       STATUS                   PORTS     NAMES
d3f98566b856   hello-world   "/hello"   2 hours ago   Exited (0) 2 hours ago             gallant_kepler
[root@iZuf6g4e6vhdv58sz2z1klZ ~]#

启动容器(运行镜像)

docker run [OPTIONS] IMAGE [COMMAND] [ARG...]

[root@iZuf6g4e6vhdv58sz2z1klZ ~]# docker run --help

Usage:  docker run [OPTIONS] IMAGE [COMMAND] [ARG...]


OPTIONS:选项
-i:表示启动一个可交互的容器,并持续打开标准输入
-t:表示使用终端关联到容器的标准输入输出上
-d:表示将容器放置在后台运行
-rm:退出后即删除容器
-name:表示定义容器唯一名称

IMAGE:表示要运行的镜像
COMMAND:表示启动容器时要运行的命令
  • 交互式启动一个容器
[root@iZuf6g4e6vhdv58sz2z1klZ ~]# docker run -it docker.io/dachongming/alpine:v3.14.0 /bin/sh
/ # cat /etc/issue
Welcome to Alpine Linux 3.14
Kernel \\r on an \\m (\\l)

/ # exit
[root@iZuf6g4e6vhdv58sz2z1klZ ~]#
  • 非交互式启动一个容器
[root@iZuf6g4e6vhdv58sz2z1klZ ~]# docker run -rm docker.io/dachongming/alpine:v3.14.0 /bin/echo hello
  • 后台运行
[root@iZuf6g4e6vhdv58sz2z1klZ ~]# docker run -d docker.io/dachongming/alpine:v3.14.0 /bin/sleep 300
[root@iZuf6g4e6vhdv58sz2z1klZ ~]# docker ps -a
CONTAINER ID   IMAGE                        COMMAND            CREATED          STATUS                     PORTS     NAMES
50d3d748b4f2   dachongming/alpine:v3.14.0   "/bin/sleep 300"   4 seconds ago    Up 3 seconds                         nervous_lumiere
aaed2bd3a058   dachongming/alpine:v3.14.0   "/bin/sh"          10 minutes ago   Exited (0) 9 minutes ago             nervous_allen
d3f98566b856   hello-world                  "/hello"           2 hours ago      Exited (0) 2 hours ago               gallant_kepler

进入容器

docker exec -ti CONTAINER ID /bin/sh

[root@iZuf6g4e6vhdv58sz2z1klZ ~]# docker exec -ti --name myalphin 50d3d748b4f2 /bin/sh
/ # cat /etc/issue
Welcome to Alpine Linux 3.14
Kernel \\r on an \\m (\\l)

/ #

停止容器

docker stop CONTAINER ID

[root@iZuf6g4e6vhdv58sz2z1klZ ~]# docker stop 50d3d748b4f2
50d3d748b4f2
[root@iZuf6g4e6vhdv58sz2z1klZ ~]# docker ps -a
CONTAINER ID   IMAGE                        COMMAND            CREATED          STATUS                        PORTS     NAMES
50d3d748b4f2   dachongming/alpine:v3.14.0   "/bin/sleep 300"   4 minutes ago    Exited (137) 14 seconds ago             nervous_lumiere
aaed2bd3a058   dachongming/alpine:v3.14.0   "/bin/sh"          15 minutes ago   Exited (0) 14 minutes ago               nervous_allen
d3f98566b856   hello-world                  "/hello"           2 hours ago      Exited (0) 2 hours ago                  gallant_kepler

重启

docker restart CONTAINER ID

删除容器

docker rm CONTAINER ID

or

docker rm -f CONTAINER_NAME

写入文件持久保存

docker commit -p CONTAINER ID docker.io/dachongming/alpine:v3.14.0_with_1.txt

导入/导出镜像

  • 导出

    docker save IMAGE_ID > name:tag.tar

  • 导入

    docker load < name\\:tag.tar

查看容器的日志

docker logs CONTAINER_ID

Docker容器的高级操作

下载Nginx镜像

docker pull nginx:tag

[root@iZuf6g4e6vhdv58sz2z1klZ ~]# docker pull nginx
Using default tag: latest
latest: Pulling from library/nginx
69692152171a: Pull complete 
30afc0b18f67: Pull complete 
596b1d696923: Pull complete 
febe5bd23e98: Pull complete 
8283eee92e2f: Pull complete 
351ad75a6cfa: Pull complete 
Digest: sha256:6d75c99af15565a301e48297fa2d121e15d80ad526f8369c526324f0f7ccb750
Status: Downloaded newer image for nginx:latest
docker.io/library/nginx:latest

端口映射

docker run --rm --name mynginx -d -p81:80 dachongming/nginx:latest

[root@iZuf6g4e6vhdv58sz2z1klZ ~]# docker tag d1a364dc548d dachongming/nginx:latest
[root@iZuf6g4e6vhdv58sz2z1klZ ~]# docker run --rm --name mynginx -d -p81:80 dachongming/nginx:latest
48c64b903bb2a260de104be1fa4c8597d291083d6edcff6b19f1a41d10ef7582
[root@iZuf6g4e6vhdv58sz2z1klZ ~]# docker ps -a
CONTAINER ID   IMAGE                        COMMAND                  CREATED         STATUS                      PORTS                               NAMES
48c64b903bb2   dachongming/nginx:latest     "/docker-entrypoint.…"   6 seconds ago   Up 4 seconds                0.0.0.0:81->80/tcp, :::81->80/tcp   mynginx
50d3d748b4f2   dachongming/alpine:v3.14.0   "/bin/sleep 300"         18 hours ago    Exited (137) 18 hours ago                                       nervous_lumiere
aaed2bd3a058   dachongming/alpine:v3.14.0   "/bin/sh"                18 hours ago    Exited (0) 18 hours ago                                         nervous_allen
d3f98566b856   hello-world                  "/hello"                 20 hours ago    Exited (0) 20 hours ago                                         gallant_kepler
[root@iZuf6g4e6vhdv58sz2z1klZ ~]#

在浏览器输入：IP:81

image-20210617144433810

挂载数据卷

docker run -d --rm --name nginx_baidu -p81:80 -v/mydata/html:/usr/share/nginx/html dachongming/nginx:latest

[root@iZuf6g4e6vhdv58sz2z1klZ ~]# cd /mydata/
[root@iZuf6g4e6vhdv58sz2z1klZ mydata]# ls
bill  BlogLee  blogleev2  docker
[root@iZuf6g4e6vhdv58sz2z1klZ mydata]# mkdir html
[root@iZuf6g4e6vhdv58sz2z1klZ mydata]# ls
bill  BlogLee  blogleev2  docker  html
[root@iZuf6g4e6vhdv58sz2z1klZ mydata]# wget www.baidu.com -O index.html
--2021-06-17 14:50:48--  http://www.baidu.com/
Resolving www.baidu.com (www.baidu.com)... 112.80.248.76, 112.80.248.75
Connecting to www.baidu.com (www.baidu.com)|112.80.248.76|:80... connected.
HTTP request sent, awaiting response... 200 OK
Length: 2381 (2.3K) [text/html]
Saving to: ‘index.html’

index.html                  100%[========================================>]   2.33K  --.-KB/s    in 0s      

2021-06-17 14:50:48 (171 MB/s) - ‘index.html’ saved [2381/2381]

[root@iZuf6g4e6vhdv58sz2z1klZ mydata]# ls
bill  BlogLee  blogleev2  docker  html  index.html
[root@iZuf6g4e6vhdv58sz2z1klZ mydata]# mv index.html ./html
[root@iZuf6g4e6vhdv58sz2z1klZ mydata]# ls
bill  BlogLee  blogleev2  docker  html
[root@iZuf6g4e6vhdv58sz2z1klZ mydata]# cd html/
[root@iZuf6g4e6vhdv58sz2z1klZ html]# LS
-bash: LS: command not found
[root@iZuf6g4e6vhdv58sz2z1klZ html]# ls
index.html
[root@iZuf6g4e6vhdv58sz2z1klZ html]# cat index.html 
[root@iZuf6g4e6vhdv58sz2z1klZ html]# docker run -d --rm --name nginx_baidu -p81:80 -v/mydata/html:/usr/share/nginx/html dachongming/nginx:latest
ef46c492a7d8bb60311b56e6685c77e72eda70bac0ed702e85f1696763e5fcc8
[root@iZuf6g4e6vhdv58sz2z1klZ html]#

此时访问：IP:81

image-20210617145708073

传递环境变量

docker run --rm -e KEY=VALUE alpine:latest printenv

[root@iZuf6g4e6vhdv58sz2z1klZ html]# docker run --rm -e KEY=VALUE alpine:latest printenv
PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
HOSTNAME=6075948f8101
KEY=VALUE
HOME=/root
[root@iZuf6g4e6vhdv58sz2z1klZ html]# docker run --rm alpine:latest printenv
PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
HOSTNAME=ec1fbe854da2
HOME=/root
[root@iZuf6g4e6vhdv58sz2z1klZ html]#

容器内安装软件（工具）

tee /etc/apt/sources.list << EOF
deb http://mirrors.163.com/debian/ jessie main non-free contrib
deb http://mirrors.163.com/debian/ jessie-updates main non-free contrib
EOF


[root@iZuf6g4e6vhdv58sz2z1klZ html]# docker exec -ti nginx_baidu /bin/bash
root@ef46c492a7d8:/# pwd
/
root@ef46c492a7d8:/# ls
bin   dev		   docker-entrypoint.sh  home  lib64  mnt  proc  run   srv  tmp  var
boot  docker-entrypoint.d  etc			 lib   media  opt  root  sbin  sys  usr
root@ef46c492a7d8:/# tee /etc/apt/sources.list << EOF
> deb http://mirrors.163.com/debian/ jessie main non-free contrib
> deb http://mirrors.163.com/debian/ jessie-updates main non-free contrib
> EOF
deb http://mirrors.163.com/debian/ jessie main non-free contrib
deb http://mirrors.163.com/debian/ jessie-updates main non-free contrib
root@ef46c492a7d8:/# apt-get update && apt-get install curl -y
Ign:1 http://mirrors.163.com/debian jessie InRelease
Get:2 http://mirrors.163.com/debian jessie-updates InRelease [16.3 kB]
Get:3 http://mirrors.163.com/debian jessie Release [77.3 kB]
Get:4 http://mirrors.163.com/debian jessie Release.gpg [1652 B]
Err:2 http://mirrors.163.com/debian jessie-updates InRelease
  The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 7638D0442B90D010
Ign:4 http://mirrors.163.com/debian jessie Release.gpg
Reading package lists... Done
W: GPG error: http://mirrors.163.com/debian jessie-updates InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 7638D0442B90D010
E: The repository 'http://mirrors.163.com/debian jessie-updates InRelease' is not signed.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.
W: GPG error: http://mirrors.163.com/debian jessie Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 7638D0442B90D010 NO_PUBKEY CBF8D6FD518E17E1
E: The repository 'http://mirrors.163.com/debian jessie Release' is not signed.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.
root@ef46c492a7d8:/# curl
curl: try 'curl --help' or 'curl --manual' for more information
root@ef46c492a7d8:/#

容器的生命周期

  • 检测本地是否存在镜像，如果不存在即从远端仓库检索
  • 利用镜像启动容器
  • 分配一个文件系统，并在只读的镜像层外挂载一层可读写层
  • 从宿主机配置的网桥接口种桥接一个虚拟接口到容器
  • 从地址池配置一个ip地址给容器
  • 执行用户指定的命令
  • 执行完毕后容器终止

image-20210617153303046

Dockerfile构建镜像

规则

  • 格式
    • #注释
    • 指令（大写）内容（小写） 实际上时不区分大小写的，但是尽量遵循
  • 从上到下按顺序执行指令
  • 第一个非注释行必须时FROM指令

4组核心的Dockerfile指令

构建：docker build . -t docker.io/dachongming/nginx:myfile

  • USER/WORKDIR

    使用哪个用户 / 相当于cd，进到某个目录

    [root@iZuf6g4e6vhdv58sz2z1klZ html]# cd /mydata/
[root@iZuf6g4e6vhdv58sz2z1klZ mydata]# mkdir dockerfile
[root@iZuf6g4e6vhdv58sz2z1klZ mydata]# cd dockerfile/
[root@iZuf6g4e6vhdv58sz2z1klZ dockerfile]# ls
'[root@iZuf6g4e6vhdv58sz2z1klZ dockerfile]# vim Dockerfile
FROM docker.io/dachongming/nginx:latest
USER nginx
WORKDIR /usr/share/nginx/html
# 构建
[root@iZuf6g4e6vhdv58sz2z1klZ dockerfile]# docker build . -t docker.io/dachongming/nginx:myfile
Sending build context to Docker daemon  2.048kB
Step 1/3 : FROM docker.io/dachongming/nginx:latest
 ---> d1a364dc548d
Step 2/3 : USER nginx
 ---> Running in 050b6999cd9c
Removing intermediate container 050b6999cd9c
 ---> 106250864654
Step 3/3 : WORKDIR /usr/share/nginx/html
 ---> Running in 616a745ff982
Removing intermediate container 616a745ff982
 ---> 95fe2fbc39a9
Successfully built 95fe2fbc39a9
Successfully tagged dachongming/nginx:myfile
[root@iZuf6g4e6vhdv58sz2z1klZ dockerfile]# docker run -rm -ti dachongming/nginx:myfile /bin/bash
unknown shorthand flag: 'r' in -rm
See 'docker run --help'.
[root@iZuf6g4e6vhdv58sz2z1klZ dockerfile]# docker run --rm -ti dachongming/nginx:myfile /bin/bash
nginx@8bd7d3174e01:/usr/share/nginx/html$ pwd
/usr/share/nginx/html
nginx@8bd7d3174e01:/usr/share/nginx/html$ whoami
nginx
nginx@8bd7d3174e01:/usr/share/nginx/html$

  • ADD/EXPOSE

    添加文件到容器 / 暴露哪个端口

    FROM docker.io/dachongming/nginx:latest
ADD index.html /usr/share/nginx/html/index.html
EXPOSE 80

  • RUN/ENV

    执行命令在镜像种安装 / 环境变量

    FROM centos:7
ENV VER 9.9.4-74.e17_6.1
RUN yum install bind-$VER -y

  • CMD/ENTRYPOINT

    启动容器时执行命令 /

 

# docker
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