docker基础

docker发展史

容器技术的发展经过的阶段：

1979年—Chroot

容器技术的概念可以追溯到1979年的UNIX Chroot。这项功能将Root目录及其它子目录变更至文件系统内的新位置，且只接受特定进程的访问，其设计目的在于为每个进程提供一套隔离化磁盘空间。1982年其被添加至BSD。

2000年—FreeBSD Jails

FreeBSD Jails与Chroot的定位类似，不过其中包含有进程沙箱机制以对文件系统、用户及网络等资源进行隔离。通过这种方式，它能够为每个Jail、定制化软件安装包乃至配置方案等提供一个对应的IP地址。Jails技术为FreeBSD系统提供了一种简单的安全隔离机制。它的不足在于这种简单性的隔离也同时会影响Jails中应用访问系统资源的灵活性。

2004年 — Solaris Zones

Solaris Zone技术为应用程序创建了虚拟的一层，让应用在隔离的Zone中运行，并实现有效的资源管理。Solaris Zone技术真正的引入了容器资源管理的概念。在应用部署的时候为Zone配置一定的资源，在运行中可以根据Zone的负载动态修改这个资源限制并且是实时生效的，在其他Zone不需要资源的时候，资源会自动切换给需要的资源的Zone，这种切换是即时的不需要人工干预的，最大化资源的利用率，在必要的情况下，也可以为单个Zone隔离一定的资源。

2008年 — LXC

LXC指代的是Linux Containers，其功能通过Cgroups以及Linux Namespaces实现。也是第一套完整的Linux容器管理实现方案。在LXC出现之前， Linux上已经有了类似 Linux-Vserver、OpenVZ 和 FreeVPS。虽然这些技术都已经成熟，但是这些解决方案还没有将它们的容器支持集成到主流 Linux 内核。相较于其它容器技术，LXC能够在无需任何额外补丁的前提下运行在原版Linux内核之上。目前LXC项目由Canonical有限公司负责赞助及托管。

2013年 — Docker

Docker项目最初是由一家名为DotCloud的平台即服务厂商所打造，其后该公司更名为Docker。Docker在起步阶段使用LXC，而后利用自己的Libcontainer库将其替换下来。与其它容器平台不同，Docker引入了一整套与容器管理相关的生态系统。其中包括一套高效的分层式容器镜像模型、一套全局及本地容器注册表、一个精简化REST API以及一套命令行界面等等。

2014年4月9日

Docker1.0发布

虚拟机属于虚拟化技术，Docker容器技术，也是一种虚拟化技术，Docker基于Go语言开发的

docker基本用法

docker对象

当你使用docker时，你是在创建和使用映像、容器、网络、卷、插件和其他对象。

• 镜像
  • 映像是一个只读模板，带有创建docker容器的说明。
  • 通常，一个映像基于另一个映像，并带有一些额外的定制。
  • 您可以创建自己的映像，也可以只使用其他人创建并在注册表中发布的映像。
• 容器
  • 容器是映像的可运行实例。
  • 您可以使用docker API或CLI创建、运行、停止、移动或删除容器。
  • 您可以将一个容器连接到一个或多个网络，将存储附加到它，甚至根据它的当前状态创建一个新的映像。

安装及使用docker

docker安装

//yum源安装
[root@localhost ~]# curl -o docker-ce.repo https://mirrors.tuna.tsinghua.edu.cn/docker-ce/linux/centos/docker-ce.repo
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
  0     0    0     0    0     0      0      0 --:--:-- --:--:-- --100  1919  100  1919    0     0   9138      0 --:--:-- --:--:-- --100  1919  100  1919    0     0   9138      0 --:--:-- --:--:-- --:--:--  9094
[root@localhost ~]# sed -i 's@https://download.docker.com@https://mirrors.tuna.tsinghua.edu.cn/docker-ce@g' docker-ce.repo
[root@localhost ~]# ls
anaconda-ks.cfg  docker-ce.repo
[root@localhost ~]# mv docker-ce.repo /etc/yum.repos.d/
[root@localhost ~]# ls /etc/yum.repos.d/
CentOS-Stream-AppStream.repo
CentOS-Stream-BaseOS.repo
CentOS-Stream-Debuginfo.repo
CentOS-Stream-Extras.repo
CentOS-Stream-HighAvailability.repo
CentOS-Stream-Media.repo
CentOS-Stream-PowerTools.repo
CentOS-Stream-RealTime.repo
docker-ce.repo
[root@localhost ~]# yum -y install docker-ce
Failed to set locale, defaulting to C.UTF-8
CentOS Stream 8 - AppStream       1.3 MB/s |  24 MB     00:18    
CentOS Stream 8 - BaseOS          7.1 MB/s |  25 MB     00:03    
CentOS Stream 8 - Extras          8.4 kB/s |  18 kB     00:02    
Docker CE Stable - x86_64          31 kB/s |  26 kB     00:00    
Dependencies resolved.
==================================================================
 Package           Arch   Version          Repository        Size
==================================================================
Installing:
 docker-ce         x86_64 3:20.10.17-3.el8 docker-ce-stable  22 M
Upgrading:
 libsemanage       x86_64 2.9-8.el8        baseos           168 k
 policycoreutils   x86_64 2.9-19.el8       baseos           374 k
     ...................................................
     
[root@localhost ~]# systemctl enable --now docker
Created symlink /etc/systemd/system/multi-user.target.wants/docker.service → /usr/lib/systemd/system/docker.service.
[root@localhost ~]# systemctl status docker
● docker.service - Docker Application Container Engine
   Loaded: loaded (/usr/lib/systemd/system/docker.service; enable>
   Active: active (running) since Fri 2022-08-05 15:01:32 CST; 19>
     Docs: https://docs.docker.com
 Main PID: 40626 (dockerd)
    Tasks: 7
   Memory: 33.5M
   CGroup: /system.slice/docker.service
           └─40626 /usr/bin/dockerd -H fd:// --containerd=/run/co>

Aug 05 15:01:32 localhost.localdomain dockerd[40626]: time="2022->
Aug 05 15:01:32 localhost.localdomain dockerd[40626]: time="2022->
Aug 05 15:01:32 localhost.localdomain dockerd[40626]: time="2022->
Aug 05 15:01:32 localhost.localdomain dockerd[40626]: time="2022->
Aug 05 15:01:32 localhost.localdomain dockerd[40626]: time="2022->
Aug 05 15:01:32 localhost.localdomain dockerd[40626]: time="2022->
Aug 05 15:01:32 localhost.localdomain dockerd[40626]: time="2022->
Aug 05 15:01:32 localhost.localdomain dockerd[40626]: time="2022->
Aug 05 15:01:32 localhost.localdomain dockerd[40626]: time="2022->
Aug 05 15:01:32 localhost.localdomain systemd[1]: Started Docker >
[root@localhost ~]# ss -antl
State  Recv-Q Send-Q Local Address:Port Peer Address:Port Process 
LISTEN 0      128          0.0.0.0:22        0.0.0.0:*            
LISTEN 0      128             [::]:22           [::]:*                 
     

docker加速

//在阿里云中找到自己的加速器
[root@localhost ~]# vim /etc/docker/daemon.json
{
          "registry-mirrors": ["https://chg2yeus.mirror.aliyuncs.com"]
}
//重启
[root@localhost ~]# systemctl  restart docker

//查看版本号
[root@localhost ~]# docker version
Client: Docker Engine - Community
 Version:           20.10.17
 API version:       1.41
 Go version:        go1.17.11
 Git commit:        100c701
 Built:             Mon Jun  6 23:03:11 2022
 OS/Arch:           linux/amd64
 Context:           default
 Experimental:      true

Server: Docker Engine - Community
 Engine:
  Version:          20.10.17
  API version:      1.41 (minimum version 1.12)
  Go version:       go1.17.11
  Git commit:       a89b842
  Built:            Mon Jun  6 23:01:29 2022
  OS/Arch:          linux/amd64
  Experimental:     false
 containerd:
  Version:          1.6.6
  GitCommit:        10c12954828e7c7c9b6e0ea9b0c02b01407d3ae1
 runc:
  Version:          1.1.2
  GitCommit:        v1.1.2-0-ga916309
 docker-init:
  Version:          0.19.0
  GitCommit:        de40ad0

 //查看加速器是否配成功 
[root@localhost ~]# docker info
Client:
 Context:    default
 Debug Mode: false
 Plugins:
  app: Docker App (Docker Inc., v0.9.1-beta3)
  buildx: Docker Buildx (Docker Inc., v0.8.2-docker)
  scan: Docker Scan (Docker Inc., v0.17.0)

Server:
 Containers: 0
  Running: 0
  Paused: 0
  Stopped: 0
 Images: 0
 Server Version: 20.10.17
 Storage Driver: overlay2
  Backing Filesystem: xfs
  Supports d_type: true
  Native Overlay Diff: true
  userxattr: false
 Logging Driver: json-file
 Cgroup Driver: cgroupfs
 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: 10c12954828e7c7c9b6e0ea9b0c02b01407d3ae1
 runc version: v1.1.2-0-ga916309
 init version: de40ad0
 Security Options:
  seccomp
   Profile: default
 Kernel Version: 4.18.0-257.el8.x86_64
 Operating System: CentOS Stream 8
 OSType: linux
 Architecture: x86_64
 CPUs: 1
 Total Memory: 1.903GiB
 Name: localhost.localdomain
 ID: SM34:ABOD:NLYU:WMEG:JRSP:J6BX:VAAM:E7BP:EZXY:HXK5:6XGW:B2ZD
 Docker Root Dir: /var/lib/docker
 Debug Mode: false
 Registry: https://index.docker.io/v1/
 Labels:
 Experimental: false
 Insecure Registries:
  127.0.0.0/8
 Registry Mirrors:
  https://chg2yeus.mirror.aliyuncs.com/
 Live Restore Enabled: false

//拉取镜像
[root@localhost ~]# docker pull centos
Using default tag: latest
latest: Pulling from library/centos
a1d0c7532777: Pull complete 
Digest: sha256:a27fd8080b517143cbbbab9dfb7c8571c40d67d534bbdee55bd6c473f432b177
Status: Downloaded newer image for centos:latest
docker.io/library/centos:latest

docker常用操作

命令	功能
docker search	在Docker Hub上搜索映像
docker pull	从注册表中提取映像或存储库
docker images	图片列表
docker create	创建一个新的容器
docker start	启动一个或多个停止的容器
docker run	在新容器中运行命令
docker attach	连接到运行的容器
docker ps	列表容器
docker logs	获取容器日志
docker restart	重启一个容器
docker stop	停止一个或多个运行中的容器
docker kill	杀死一个或多个运行中的容器
docker rm	移除onne或多个容器
docker exec	在运行的容器中运行命令
docker info	显示整个系统的信息
docker inspect	返回Docker对象的低级信息

//在Docker Hub上搜索映像
[root@localhost ~]# docker search httpd
NAME                                 DESCRIPTION                                     STARS     OFFICIAL   AUTOMATED
httpd                                The Apache HTTP Server Project                  4107      [OK]       
centos/httpd-24-centos7              Platform for running Apache httpd 2.4 or bui…   44                   
centos/httpd                                                                         35                   [OK]
clearlinux/httpd                     httpd HyperText Transfer Protocol (HTTP) ser…   2                    
hypoport/httpd-cgi                   httpd-cgi                                       2                    [OK]
solsson/httpd-openidc                mod_auth_openidc on official httpd image, ve…   2                    [OK]
dockerpinata/httpd                                                                   1                    
nnasaki/httpd-ssi                    SSI enabled Apache 2.4 on Alpine Linux          1                    
lead4good/httpd-fpm                  httpd server which connects via fcgi proxy h…   1                    [OK]
inanimate/httpd-ssl                  A play container with httpd, ssl enabled, an…   1                    [OK]
publici/httpd                        httpd:latest                                    1                    [OK]
dariko/httpd-rproxy-ldap             Apache httpd reverse proxy with LDAP authent…   1                    [OK]
manageiq/httpd                       Container with httpd, built on CentOS for Ma…   1                    [OK]
centos/httpd-24-centos8                                                              1                    
manasip/httpd                                                                        0                    
amd64/httpd                          The Apache HTTP Server Project                  0                    
patrickha/httpd-err                                                                  0                    
manageiq/httpd_configmap_generator   Httpd Configmap Generator                       0                    [OK]
httpdss/archerysec                   ArcherySec repository                           0                    [OK]
paketobuildpacks/httpd                                                               0                    
httpdocker/kubia                                                                     0                    
sandeep1988/httpd-new                httpd-new                                       0                    
e2eteam/httpd                                                                        0                    
19022021/httpd-connection_test       This httpd image will test the connectivity …   0                    
sherazahmedvaival/httpd-php-fpm74                                                    0      

//拉取镜像
[root@localhost ~]# docker pull busybox
Using default tag: latest
latest: Pulling from library/busybox
5cc84ad355aa: Pull complete 
Digest: sha256:5acba83a746c7608ed544dc1533b87c737a0b0fb730301639a0179f9344b1678
Status: Downloaded newer image for busybox:latest
docker.io/library/busybox:latest

//列出镜像
[root@localhost ~]# docker images
REPOSITORY   TAG       IMAGE ID       CREATED         SIZE
busybox      latest    beae173ccac6   7 months ago    1.24MB
centos       latest    5d0da3dc9764   10 months ago   231MB

//创建容器
[root@localhost ~]# docker create busybox
a40586c08b1f43baab3ed1b1c6630d7e5abaf98fec3a9331e5b5e4461e2b055e
[root@localhost ~]# docker ps -a
CONTAINER ID   IMAGE     COMMAND   CREATED         STATUS    PORTS     NAMES
a40586c08b1f   busybox   "sh"      8 seconds ago   Created             compassionate_jemison

//启动容器
[root@localhost ~]# docker start a40586c08b1f
a40586c08b1f
[root@localhost ~]# docker ps -a
CONTAINER ID   IMAGE     COMMAND   CREATED         STATUS                     PORTS     NAMES
a40586c08b1f   busybox   "sh"      2 minutes ago   Exited (0) 9 seconds ago             compassionate_jemison

//在新容器中运行命令
[root@localhost ~]# docker run -d --name jiang -p 80:80 httpd
Unable to find image 'httpd:latest' locally
latest: Pulling from library/httpd
a2abf6c4d29d: Pull complete 
dcc4698797c8: Pull complete 
41c22baa66ec: Pull complete 
67283bbdd4a0: Pull complete 
d982c879c57e: Pull complete 
Digest: sha256:0954cc1af252d824860b2c5dc0a10720af2b7a3d3435581ca788dff8480c7b32
Status: Downloaded newer image for httpd:latest
693309fb9988381bace79b1c3a097aa4364169ed86ca1513e7c6070a60d26202
docker: Error response from daemon: driver failed programming external connectivity on endpoint jiang (c103dbb502e7c9a90d7e73114e59411cc2ab6d7bdbc43f8c3d438210a3524332):  (iptables failed: iptables --wait -t nat -A DOCKER -p tcp -d 0/0 --dport 80 -j DNAT --to-destination 172.17.0.3:80 ! -i docker0: iptables: No chain/target/match by that name.
 (exit status 1)).

//移除onne或多个容器
[root@localhost ~]# docker ps -a
CONTAINER ID   IMAGE     COMMAND              CREATED              STATUS                     PORTS     NAMES
22427e48e3ef   httpd     "httpd-foreground"   About a minute ago   Created                              web
693309fb9988   httpd     "httpd-foreground"   About a minute ago   Created                              jiang
33958a6f8cfc   busybox   "sleep 6000"         6 minutes ago        Up 6 minutes                         busy_gates
a40586c08b1f   busybox   "sh"                 9 minutes ago        Exited (0) 7 minutes ago             compassionate_jemison
[root@localhost ~]# docker rm -f jiang
jiang
[root@localhost ~]# docker ps -a
CONTAINER ID   IMAGE     COMMAND              CREATED              STATUS                     PORTS     NAMES
22427e48e3ef   httpd     "httpd-foreground"   About a minute ago   Created                              web
33958a6f8cfc   busybox   "sleep 6000"         6 minutes ago        Up 6 minutes                         busy_gates
a40586c08b1f   busybox   "sh"                 9 minutes ago        Exited (0) 7 minutes ago             compassionate_jemison

//列表容器
[root@localhost ~]# docker ps
CONTAINER ID   IMAGE     COMMAND              CREATED              STATUS              PORTS                               NAMES
fa78f9a269ea   httpd     "httpd-foreground"   About a minute ago   Up About a minute   0.0.0.0:80->80/tcp, :::80->80/tcp   jiang
33958a6f8cfc   busybox   "sleep 6000"         9 minutes ago        Up 8 minutes                                            busy_gates

//查看日志
[root@localhost ~]# docker logs jiang
AH00558: httpd: Could not reliably determine the server's fully qualified domain name, using 172.17.0.3. Set the 'ServerName' directive globally to suppress this message
AH00558: httpd: Could not reliably determine the server's fully qualified domain name, using 172.17.0.3. Set the 'ServerName' directive globally to suppress this message
[Fri Aug 05 07:55:04.335414 2022] [mpm_event:notice] [pid 1:tid 140415116041536] AH00489: Apache/2.4.52 (Unix) configured -- resuming normal operations
[Fri Aug 05 07:55:04.335525 2022] [core:notice] [pid 1:tid 140415116041536] AH00094: Command line: 'httpd -D FOREGROUND'
192.168.205.1 - - [05/Aug/2022:07:57:47 +0000] "GET / HTTP/1.1" 200 45
192.168.205.1 - - [05/Aug/2022:07:57:48 +0000] "GET /favicon.ico HTTP/1.1" 404 196
192.168.205.1 - - [05/Aug/2022:07:57:52 +0000] "GET / HTTP/1.1" 304 -
192.168.205.1 - - [05/Aug/2022:07:57:54 +0000] "GET / HTTP/1.1" 304 -

//重启
[root@localhost ~]# docker ps
CONTAINER ID   IMAGE     COMMAND              CREATED          STATUS          PORTS                               NAMES
fa78f9a269ea   httpd     "httpd-foreground"   4 minutes ago    Up 4 minutes    0.0.0.0:80->80/tcp, :::80->80/tcp   jiang
33958a6f8cfc   busybox   "sleep 6000"         11 minutes ago   Up 11 minutes                                       busy_gates
[root@localhost ~]# docker restart busy_gates
busy_gates
[root@localhost ~]# docker ps
CONTAINER ID   IMAGE     COMMAND              CREATED          STATUS          PORTS                               NAMES
fa78f9a269ea   httpd     "httpd-foreground"   5 minutes ago    Up 5 minutes    0.0.0.0:80->80/tcp, :::80->80/tcp   jiang
33958a6f8cfc   busybox   "sleep 6000"         13 minutes ago   Up 24 seconds                                       busy_gates

//停止
[root@localhost ~]# docker ps
CONTAINER ID   IMAGE     COMMAND              CREATED          STATUS          PORTS                               NAMES
fa78f9a269ea   httpd     "httpd-foreground"   5 minutes ago    Up 5 minutes    0.0.0.0:80->80/tcp, :::80->80/tcp   jiang
33958a6f8cfc   busybox   "sleep 6000"         13 minutes ago   Up 24 seconds                                       busy_gates

[root@localhost ~]# docker stop jiang
jiang
[root@localhost ~]# docker ps
CONTAINER ID   IMAGE     COMMAND        CREATED          STATUS              PORTS     NAMES
33958a6f8cfc   busybox   "sleep 6000"   14 minutes ago   Up About a minute             busy_gates

//杀死
[root@localhost ~]# docker ps
CONTAINER ID   IMAGE     COMMAND        CREATED          STATUS         PORTS     NAMES
33958a6f8cfc   busybox   "sleep 6000"   15 minutes ago   Up 2 minutes             busy_gates
[root@localhost ~]# docker kill 33958a6f8cfc
33958a6f8cfc
[root@localhost ~]# docker ps
CONTAINER ID   IMAGE     COMMAND   CREATED   STATUS    PORTS     NAMES

//删除所有容器
[root@localhost ~]# docker ps -aq
d5d7b39a2727
2c8b6ad3b62d
5733aa439b39
82acfd1482de
fa78f9a269ea
22427e48e3ef
33958a6f8cfc
a40586c08b1f
[root@localhost ~]# docker rm -f $(docker ps -aq)
d5d7b39a2727
2c8b6ad3b62d
5733aa439b39
82acfd1482de
fa78f9a269ea
22427e48e3ef
33958a6f8cfc
a40586c08b1f
[root@localhost ~]# docker ps -aq

//查看更加详细的信息
[root@localhost ~]# docker run -d httpd
6a9ae218e276aa3e6c62a7500d7fe025ca47748c2b62270a232924ff658e2487
[root@localhost ~]# docker ps
CONTAINER ID   IMAGE     COMMAND              CREATED         STATUS         PORTS     NAMES
6a9ae218e276   httpd     "httpd-foreground"   4 seconds ago   Up 3 seconds   80/tcp    confident_banach
[root@localhost ~]# docker inspect 6a9ae218e276
[
    {
        "Id": "6a9ae218e276aa3e6c62a7500d7fe025ca47748c2b62270a232924ff658e2487",
        "Created": "2022-08-05T08:07:24.240743215Z",
        "Path": "httpd-foreground",
        "Args": [],
        "State": {
            "Status": "running",
            "Running": true,
            "Paused": false,
            "Restarting": false,
            "OOMKilled": false,
            "Dead": false,
            "Pid": 165179,
            "ExitCode": 0,
...............................................
            
 //进入容器
[root@localhost ~]# docker ps 
CONTAINER ID   IMAGE     COMMAND              CREATED         STATUS         PORTS     NAMES
6a9ae218e276   httpd     "httpd-foreground"   2 minutes ago   Up 2 minutes   80/tcp    confident_banach
[root@localhost ~]# 
[root@localhost ~]# 
[root@localhost ~]# docker attach 6a9ae218e276
 //进入容器
[root@localhost ~]# docker exec -it 6a9ae218e276 /bin/bash

存储驱动

每个docker容器都有一个本地存储空间，用于保护层叠的镜像层（Image Layer）以及挂载的容器文件系统。

默认情况下，容器的所有读写操作都发生在其镜像层上或挂载的文件系统上，所以存储是容器的性能和稳定性不可获取的一个环节。

对比以往的本地存储，本地存储是通过存储驱动（Storage Driver）进行管理的，有时候也称之为Graph Driver或者GraphDriver。
虽然存储驱动在上层抽象设计中都采用栈式镜像层存储和写时复制的设计思想，但是docker在linux底层支持几种不同的存储驱动的具体实现，每一种实现方式都采用了不同的方法实现了镜像层和写时复制。

总结，如下表所示：

	传统存储驱动	Docker存储驱动
设计思想	栈式镜像存储	栈式镜像存储
设计思想	写时复制	写时复制
区别（linux）	单一实现	基于linux底层支持，采用了不同的方法实现上述两种思想
区别（windows）	单一实现	windows Filter