docker使用

2018-09-05

一、简介

Docker 和传统虚拟化方式的不同之处。传统虚拟机技术是虚拟出一套硬件后，在其上运行一个完整操作系统，在该系统上再运行所需应用进程；而容器内的应用进程直接运行于宿主的内核，容器内没有自己的内核，而且也没有进行硬件虚拟。因此容器要比传统虚拟机更为轻便

镜像（Image）和容器（Container）的关系，就像是面向对象程序设计中的类和实例一样，镜像是静态的定义，容器是镜像运行时的实体。容器可以被创建、启动、停止、删除、暂停等

二、安装须知

操作系统: Mac OS Yosemite 10.10.5

Mac地址：https://download.docker.com/mac/stable/Docker.dmg

Docker.dmg：安装提供Docker Engine，Docker CLI客户端，Docker Compose和Docker Machine

三、安装

1）运行Docker.dmg安装

2）配置个人加速镜像（我使用阿里云https://cr.console.aliyun.com/#/accelerator）

3) 运行docker version和docker info检查

➜ docker version
Client:
 Version:      17.03.0-ce
 API version:  1.26
 Go version:   go1.7.5
 Git commit:   60ccb22
 Built:        Thu Feb 23 10:40:59 2017
 OS/Arch:      darwin/amd64

Server:
 Version:      17.03.0-ce
 API version:  1.26 (minimum version 1.12)
 Go version:   go1.7.5
 Git commit:   3a232c8
 Built:        Tue Feb 28 07:52:04 2017
 OS/Arch:      linux/amd64
 Experimental: true

➜ docker info
Containers: 1
 Running: 1
 Paused: 0
 Stopped: 0
Images: 1
Server Version: 17.03.0-ce
Storage Driver: overlay2
 Backing Filesystem: extfs
 Supports d_type: true
 Native Overlay Diff: true
Logging Driver: json-file
Cgroup Driver: cgroupfs
Plugins:
 Volume: local
 Network: bridge host ipvlan macvlan null overlay
Swarm: inactive
Runtimes: runc
Default Runtime: runc
Init Binary: docker-init
containerd version: 977c511eda0925a723debdc94d09459af49d082a
runc version: a01dafd48bc1c7cc12bdb01206f9fea7dd6feb70
init version: 949e6fa
Security Options:
 seccomp
  Profile: default
Kernel Version: 4.9.12-moby
Operating System: Alpine Linux v3.5
OSType: linux
Architecture: x86_64
CPUs: 2
Total Memory: 1.952 GiB
Name: moby
ID: V5PN:CAOJ:YYKT:B7IK:PTP3:OQKS:Q26Q:UJYZ:OG2K:HSPK:WRME:KJP5
Docker Root Dir: /var/lib/docker
Debug Mode (client): false
Debug Mode (server): true
 File Descriptors: 23
 Goroutines: 32
 System Time: 2017-03-27T03:33:06.945792584Z
 EventsListeners: 1
No Proxy: 127.0.0.1
Registry: https://index.docker.io/v1/
Experimental: true
Insecure Registries:
 127.0.0.0/8
Registry Mirrors:
 https://xxxxx.mirror.aliyuncs.com
Live Restore Enabled: false

四、运行nginx

启动运行nginx, 执行docker run -d -p 80:80 --name webserver nginx

➜ docker run -d -p 80:80 --name webserver nginx
Unable to find image 'nginx:latest' locally
latest: Pulling from library/nginx
693502eb7dfb: Pull complete
6decb850d2bc: Pull complete
c3e19f087ed6: Pull complete
Digest: sha256:52a189e49c0c797cfc5cbfe578c68c225d160fb13a42954144b29af3fe4fe335
Status: Downloaded newer image for nginx:latest
4b11e6ed897d6df195936f60916ffda704d55f75645270f338a10b68480112e7

启动bash命令交互操作客户端

1 2	➜ docker exec -it webserver bash root@2964bd62006a:/#

停止niginx, 运行docker stop webserver

1 2	➜ docker stop webserver webserver

删除nginx, 运行docker rm webserver

1 2	➜ docker rm webserver webserver

五、运行ubuntu

镜像官方仓库：https://hub.docker.com/explore/

下载ubuntu

➜ docker pull ubuntu:14.04
14.04: Pulling from library/ubuntu
30d541b48fc0: Pull complete
8ecd7f80d390: Pull complete
46ec9927bb81: Pull complete
2e67a4d67b44: Pull complete
7d9dd9155488: Pull complete
Digest: sha256:62a5dce5ceccd7f1cb2672a571ebee52cad1f08eec9b57fe4965fb0968a9602e
Status: Downloaded newer image for ubuntu:14.04

启动运行ubuntu

-it：这是两个参数，一个是 -i：交互式操作，一个是 -t 终端。我们这里打算进入 bash 执行一些命令并查看返回结果，因此我们需要交互式终端。

–rm：这个参数是说容器退出后随之将其删除。默认情况下，为了排障需求，退出的容器并不会立即删除，除非手动 docker rm。我们这里只是随便执行个命令，看看结果，不需要排障和保留结果，因此使用 –rm 可以避免浪费空间。

ubuntu:14.04：这是指用 ubuntu:14.04 镜像为基础来启动容器。

–name myUbuntu：给容器取一个别名叫myUbuntu

1 2	➜ docker run -it --rm --name myUbuntu ubuntu:14.04 root@2ef73a93ef7b:/#

或者不指定ubuntu版本，直接启动时，直接下载最新版本ubuntu:latest

➜ docker run -it --name myUbuntu ubuntu:14.04
Unable to find image 'ubuntu:latest' locally
latest: Pulling from library/ubuntu
d54efb8db41d: Pull complete
f8b845f45a87: Pull complete
e8db7bf7c39f: Pull complete
9654c40e9079: Pull complete
6d9ef359eaaa: Pull complete
Digest: sha256:dd7808d8792c9841d0b460122f1acf0a2dd1f56404f8d1e56298048885e45535
Status: Downloaded newer image for ubuntu:latest
root@366ea11633cf:/#

停止ubuntu容器

1 2	➜ docker stop myUbuntu myUbuntu

删除ubuntu容器

1 2	➜ docker rm myUbuntu myUbuntu

查看历史镜像

➜ docker images
REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
nginx               latest              6b914bbcb89e        3 weeks ago         182 MB
ubuntu              14.04               7c09e61e9035        3 weeks ago         188 MB

删除ubuntu镜像

使用docker rmi <IMAGE ID>删除，但是必须先要docker rm myUbuntu才能删除镜像

➜ docker rmi 7c09e61e9035
Untagged: ubuntu:14.04
Untagged: ubuntu@sha256:62a5dce5ceccd7f1cb2672a571ebee52cad1f08eec9b57fe4965fb0968a9602e
Deleted: sha256:7c09e61e90350e8f5c0cba2979003bdfe32c2d027b68b4f0cf9063cdd7b4bafd
Deleted: sha256:304aecb5e13929f85d3ce2e9d83d0212866c8e55a460c94cf24bd75da1c7c153
Deleted: sha256:f302be18d46a45c0edbbd9b4bc02db764a4b0b8cd9bd0490f33dfaff039a3b62
Deleted: sha256:c523f3173f6028e5329fd401331c375f7b9b9e831d915fafaf358f55e36e3747
Deleted: sha256:94e631422130dc414878fd05efe3d59de44c9d8904696a7c299a83f378a92845
Deleted: sha256:c29b5eadf94a90a2abda13e765d4fad4825fd15621dea1d9a98b60b89b835c2a

查看docker进程

1
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➜ docker ps -a
CONTAINER ID        IMAGE               COMMAND             CREATED              STATUS                      PORTS               NAMES
366ea11633cf        ubuntu              "/bin/bash"         About a minute ago   Exited (0) 59 seconds ago                       myUbuntu

六、制作自定义nginx

1) 启动nginx

➜  docker run -d -p 80:80 --name webserver nginx
Unable to find image 'nginx:latest' locally
latest: Pulling from library/nginx
693502eb7dfb: Pull complete
6decb850d2bc: Pull complete
c3e19f087ed6: Pull complete
Digest: sha256:52a189e49c0c797cfc5cbfe578c68c225d160fb13a42954144b29af3fe4fe335
Status: Downloaded newer image for nginx:latest
2964bd62006acd43611ea045e8152f651905e213c392e008a59eebe667080b3d

2）启动bash控制台并修改index.html内容

➜  docker exec -it webserver bash
root@2964bd62006a:/# ls
bin  boot  dev	etc  home  lib	lib64  media  mnt  opt	proc  root  run  sbin  srv  sys  tmp  usr  var
root@2964bd62006a:/# echo '<h1>Hello, Docker!</h1>' > /usr/share/nginx/html/index.html
root@2964bd62006a:/# exit
exit

3）查看容器修改内容

➜  docker diff webserver
C /root
A /root/.bash_history
C /run
A /run/nginx.pid
C /usr/share/nginx/html/index.html
C /var/cache/nginx
A /var/cache/nginx/client_temp
A /var/cache/nginx/fastcgi_temp
A /var/cache/nginx/proxy_temp
A /var/cache/nginx/scgi_temp
A /var/cache/nginx/uwsgi_temp

4）制作v2版本tag的nginx

1 2	➜ docker commit --author "zhengyong" --message "update index.htm" webserver nigix:v2 sha256:b86a71250cf4e41a34af24b7e2924e3909ecdf74262195d6ac30fd57bbdbaf35

5) 启动v2版本nginx

1 2	➜ docker run -d -p 80:80 --name ng nigix:v2 72f15356de38c26456cdee8a68651a2de25e59d8f8e4ce31e82c434927ff4b4f

七、Dockerfile

1）创建工程目录和Dockerfile文件

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➜ mkdir mynginx
➜ cd mynginx
➜ touch Dockerfile

2）Dockerfile文件内容

1 2	FROM nginx RUN echo '<h1>Hello, Docker!</h1>' > /usr/share/nginx/html/index.html

3) 构建docker镜像

使用命令docker build -t nginx:v3 .构建：

➜ docker build -t nginx:v3 .
Sending build context to Docker daemon 2.048 kB
Step 1/2 : FROM nginx
 ---> 6b914bbcb89e
Step 2/2 : RUN echo '<h1>Hello, Docker!</h1>' > /usr/share/nginx/html/index.html
 ---> Running in a41235243cb9
 ---> 7a2e14fdfefb
Removing intermediate container a41235243cb9
Successfully built 7a2e14fdfefb

docker导致mac硬盘空间不足：

docker rm $(docker ps -a -q)
docker rmi $(docker images -q)
docker volume rm $(docker volume ls |awk '{print $2}')
rm -rf ~/Library/Containers/com.docker.docker/Data/*