Docker理论与实践（二）
文章作者：Tyan 博客：noahsnail.com
1. Docker命令
# 列出系统中的所有容器
docker ps -a
# 结果
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
aadf299b179b hello-world "/hello" 20 minutes ago Exited (0) 20 minutes ago gloomy_khorana
# docker ps仅列出当前运行的容器
docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
# 运行whalesay镜像
docker fun docker/whalesay cowsay boo1.1 docker run hello-world解析
这个命令总共有三部分：
- docker：告诉操作系统你使用的是docker程序
- run：创建和运行docker容器的子命令
- hello-world：告诉docker将哪一个镜像加载到容器中
1.2 docker run hello-world的运行过程
image是一个文件系统，里面有运行时使用的参数。它没有状态且不能改变。容器是镜像的运行实例。命令执行时，Docker Engine会进行以下的步骤：
- 检查hello-world软件镜像是否存在
- 如果不存在，从Docker Hub上下载hello-world
- 加载镜像到容器中并运行
运行是根据镜像的构建过程执行的，可能一直运行，也可能执行几个命令就退出。镜像可能是非常复杂的，例如镜像可以启动一个数据库软件。
2. 创建自己的docker image
2.1 写一个Dockerfile
$ mkdir Docker
$ cd Docker
$ touch Dockerfile
$ vim Dockerfile在Dockerfile中加入下面的代码并保存：
FROM docker/whalesay:latest
RUN apt-get -y update && apt-get install -y fortunes
CMD /usr/games/fortune -a | cowsay2.2 从Dockerfile中创建image
# 查看Dockerfile内容
$ cat Dockerfile
# 构建image
$ docker build -t docker-whale .2.3 创建image的过程
- 首先Docker检查确保有构建的需要的东西
Sending build context to Docker daemon 2.048 kB- 然后Docker加载whalesay镜像
Step 1 : FROM docker/whalesay:latest
---> 6b362a9f73eb- Docker开始执行
apt-get命令
Step 2 : RUN apt-get -y update && apt-get install -y fortunes
---> Running in 3c381fdef64a
Ign http://archive.ubuntu.com trusty InRelease
Get:1 http://archive.ubuntu.com trusty-updates InRelease [65.9 kB]
Get:2 http://archive.ubuntu.com trusty-security InRelease [65.9 kB]
Hit http://archive.ubuntu.com trusty Release.gpg
Get:3 http://archive.ubuntu.com trusty-updates/main Sources [473 kB]
Get:4 http://archive.ubuntu.com trusty-updates/restricted Sources [5247 B]
Get:5 http://archive.ubuntu.com trusty-updates/universe Sources [207 kB]
Get:6 http://archive.ubuntu.com trusty-updates/main amd64 Packages [1122 kB]
Get:7 http://archive.ubuntu.com trusty-updates/restricted amd64 Packages [23.5 kB]
Get:8 http://archive.ubuntu.com trusty-updates/universe amd64 Packages [483 kB]
Hit http://archive.ubuntu.com trusty Release
Get:9 http://archive.ubuntu.com trusty-security/main Sources [152 kB]
Get:10 http://archive.ubuntu.com trusty-security/restricted Sources [3944 B]
Get:11 http://archive.ubuntu.com trusty-security/universe Sources [49.4 kB]
Get:12 http://archive.ubuntu.com trusty-security/main amd64 Packages [659 kB]
Get:13 http://archive.ubuntu.com trusty-security/restricted amd64 Packages [20.2 kB]
Get:14 http://archive.ubuntu.com trusty-security/universe amd64 Packages [178 kB]
Hit http://archive.ubuntu.com trusty/main Sources
Hit http://archive.ubuntu.com trusty/restricted Sources
Hit http://archive.ubuntu.com trusty/universe Sources
Hit http://archive.ubuntu.com trusty/main amd64 Packages
Hit http://archive.ubuntu.com trusty/restricted amd64 Packages
Hit http://archive.ubuntu.com trusty/universe amd64 Packages
Fetched 3508 kB in 25s (139 kB/s)
Reading package lists...
Reading package lists...
Building dependency tree...
Reading state information...
The following extra packages will be installed:
fortune-mod fortunes-min librecode0
Suggested packages:
x11-utils bsdmainutils
The following NEW packages will be installed:
fortune-mod fortunes fortunes-min librecode0
0 upgraded, 4 newly installed, 0 to remove and 87 not upgraded.
Need to get 1961 kB of archives.
After this operation, 4817 kB of additional disk space will be used.
Get:1 http://archive.ubuntu.com/ubuntu/ trusty/main librecode0 amd64 3.6-21 [771 kB]
Get:2 http://archive.ubuntu.com/ubuntu/ trusty/universe fortune-mod amd64 1:1.99.1-7 [39.5 kB]
Get:3 http://archive.ubuntu.com/ubuntu/ trusty/universe fortunes-min all 1:1.99.1-7 [61.8 kB]
Get:4 http://archive.ubuntu.com/ubuntu/ trusty/universe fortunes all 1:1.99.1-7 [1089 kB]
debconf: unable to initialize frontend: Dialog
debconf: (TERM is not set, so the dialog frontend is not usable.)
debconf: falling back to frontend: Readline
debconf: unable to initialize frontend: Readline
debconf: (This frontend requires a controlling tty.)
debconf: falling back to frontend: Teletype
dpkg-preconfigure: unable to re-open stdin:
Fetched 1961 kB in 8s (221 kB/s)
Selecting previously unselected package librecode0:amd64.
(Reading database ... 13116 files and directories currently installed.)
Preparing to unpack .../librecode0_3.6-21_amd64.deb ...
Unpacking librecode0:amd64 (3.6-21) ...
Selecting previously unselected package fortune-mod.
Preparing to unpack .../fortune-mod_1%3a1.99.1-7_amd64.deb ...
Unpacking fortune-mod (1:1.99.1-7) ...
Selecting previously unselected package fortunes-min.
Preparing to unpack .../fortunes-min_1%3a1.99.1-7_all.deb ...
Unpacking fortunes-min (1:1.99.1-7) ...
Selecting previously unselected package fortunes.
Preparing to unpack .../fortunes_1%3a1.99.1-7_all.deb ...
Unpacking fortunes (1:1.99.1-7) ...
Setting up librecode0:amd64 (3.6-21) ...
Setting up fortune-mod (1:1.99.1-7) ...
Setting up fortunes-min (1:1.99.1-7) ...
Setting up fortunes (1:1.99.1-7) ...
Processing triggers for libc-bin (2.19-0ubuntu6.6) ...
---> 5c6dbfc7a7ea- 执行CMD命令
Removing intermediate container 3c381fdef64a
Step 3 : CMD /usr/games/fortune -a | cowsay
---> Running in b0df80e0d4c9
---> d1178b780ac6
Removing intermediate container b0df80e0d4c9
Successfully built d1178b780ac62.4 测试自己创建的image
$ docker images
$ docker run docker-whale
# 结果
_________________________________________
/ I suppose some of the variation between \
| Boston drivers and the rest of the |
| country is due to the progressive |
| Massachusetts Driver Education Manual |
| which I happen to have in my top desk |
| drawer. Some of the Tips for Better |
| Driving are worth considering, to wit: |
| |
| [131.16d]: |
| |
| "Directional signals are generally not |
| used except during vehicle |
| |
| inspection; however, a left-turn signal |
| is appropriate when making |
| |
| a U-turn on a divided highway." |
| |
| [96.7b]: |
| |
| "When paying tolls, remember that it is |
| necessary to release the |
| |
| quarter a full 3 seconds before passing |
| the basket if you are |
| |
| traveling more than 60 MPH." |
| |
| [110.13]: |
| |
| "When traveling on a one-way street, |
| stay to the right, so as not |
| |
\ to interfere with oncoming traffic." /
-----------------------------------------
\
\
\
## .
## ## ## ==
## ## ## ## ===
/""""""""""""""""___/ ===
~~~ {~~ ~~~~ ~~~ ~~~~ ~~ ~ / ===- ~~~
\______ o __/
\ \ __/
\____\______/ 3. 在Docker Hub上创建自己的仓库，与Git类似
略.
4. Tag, push, and pull your image
Step 1: Tag and push the image
- 用docker images查看你当前的image
REPOSITORY TAG IMAGE ID CREATED SIZE
docker-whale latest d1178b780ac6 2 hours ago 274.9 MB
hello-world latest c54a2cc56cbb 11 weeks ago 1.848 kB
docker/whalesay latest 6b362a9f73eb 16 months ago 247 MB- 用docker tag命令和IMAGE ID给image打上tag，YOUR_DOCKERHUB_NAME为你的Docker Hub帐号，它起一个namespace的作用
docker tag d1178b780ac6 YOUR_DOCKERHUB_NAME/docker-whale:latest- docker images重新查看image
REPOSITORY TAG IMAGE ID CREATED SIZE
docker-whale latest d1178b780ac6 2 hours ago 274.9 MB
snailtyan/docker-whale latest d1178b780ac6 2 hours ago 274.9 MB
hello-world latest c54a2cc56cbb 11 weeks ago 1.848 kB
docker/whalesay latest 6b362a9f73eb 16 months ago 247 MB- 使用docker login命令登录你的Docker Hub账户
$ docker login
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: ***
Password:
Login Succeeded- 使用docker push将image推送到Docker Hub
$ docker push ***/docker-whale
The push refers to a repository [docker.io/***/docker-whale]
122284833f25: Pushed
5f70bf18a086: Mounted from docker/whalesay
d061ee1340ec: Mounted from docker/whalesay
d511ed9e12e1: Mounted from docker/whalesay
091abc5148e4: Mounted from docker/whalesay
b26122d57afa: Mounted from docker/whalesay
37ee47034d9b: Mounted from docker/whalesay
528c8710fd95: Mounted from docker/whalesay
1154ba695078: Mounted from docker/whalesay
latest: digest: sha256:18a6032f5726bdd6cea7c15faa02d9dcf1f12ff591c42ca15fc95c0d83de04fc size: 2614- 你可以在你的Docker Hub上看到*/docker-whale image了
Step 2: Pull your new image
- 先删除本地的docker-whale
# 用id删除image
$ docker rmi -f 7d9495d03763
# 用name删除image
$ docker rmi -f docker-whale- 通过docker run来pull image
$ docker run ***/docker-whale
Unable to find image '***/docker-whale:latest' locally
latest: Pulling from ***/docker-whale
e190868d63f8: Already exists
909cd34c6fd7: Already exists
0b9bfabab7c1: Already exists
a3ed95caeb02: Already exists
00bf65475aba: Already exists
c57b6bcc83e3: Already exists
8978f6879e2f: Already exists
8eed3712d2cf: Already exists
2bb8a73a1829: Already exists
Digest: sha256:18a6032f5726bdd6cea7c15faa02d9dcf1f12ff591c42ca15fc95c0d83de04fc
Status: Downloaded newer image for ***/docker-whale:latest
________________________________________
/ Would it help if I got out and pushed? \
| |
\ -- Princess Leia Organa /
----------------------------------------
\
\
\
## .
## ## ## ==
## ## ## ## ===
/""""""""""""""""___/ ===
~~~ {~~ ~~~~ ~~~ ~~~~ ~~ ~ / ===- ~~~
\______ o __/
\ \ __/
\____\______/ 本文参与 腾讯云自媒体同步曝光计划，分享自作者个人站点/博客。
原始发表：2016-09-22，如有侵权请联系 cloudcommunity@tencent.com 删除
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