八克里: 透過用 dockerfile 配置可以快速生成 docker image 並實現 container 部署

透過用 dockerfile 配置可以快速生成 docker image 並實現 container 部署

ref: http://dockerone.com/article/101

範例：

https://registry.hub.docker.com/u/tutum/lamp/dockerfile/

官方說明文件：

https://docs.docker.com/articles/dockerfile_best-practices/

(1) 本機 dockerfile 建立

# 在本地端的目錄下，建立一個檔案名稱為 Dockerfile

# FROM：你的 base image 為基底

# MAINTAINER：維護 images 的人

# RUN：在 images 建立過程執行的指令

# ADD：將本機的檔案或遠端的檔案加入到 image 內的目錄

# 語法請參考：https://docs.docker.com/reference/builder/

# 底下 Dockerfile 參考 https://registry.hub.docker.com/u/tutum/lamp/dockerfile/

mtchang@mt ~/SCM_code/docker/apdemo $ vim Dockerfile

FROM ubuntu:latest

MAINTAINER mtchang

# Install packages

ENV DEBIAN_FRONTEND noninteractive

RUN apt-get update && \

apt-get -y install supervisor git apache2 libapache2-mod-php5 mysql-server php5-mysql pwgen php-apc php5-mcrypt && \

echo "ServerName localhost" >> /etc/apache2/apache2.conf

#Enviornment variables to configure php

ENV PHP_UPLOAD_MAX_FILESIZE 10M

ENV PHP_POST_MAX_SIZE 10M

# 執行 docker build 會直接依據 dockerfile 內容編譯 image

mtchang@mt ~/SCM_code/docker/apdemo $ sudo docker build -t mtchang/apdemo . (點)

# 注意每個過程都會有各 hash code

Sending build context to Docker daemon 2.56 kB

Sending build context to Docker daemon

Step 0 : FROM ubuntu:latest

---> 5ba9dab47459

Step 1 : MAINTAINER mtchang

---> Running in 584aa4bb3e1c

---> 6c304964c942

Removing intermediate container 584aa4bb3e1c

Step 2 : ENV DEBIAN_FRONTEND noninteractive

---> Running in 9522aec6d092

---> 4eb8188f88d7

Removing intermediate container 9522aec6d092

Step 3 : RUN apt-get update && apt-get -y install supervisor git apache2 libapache2-mod-php5 mysql-server php5-mysql pwgen php-apc php5-mcrypt && echo "ServerName localhost" >> /etc/apache2/apache2.conf

---> Running in b7c3e263758c

...(省略數百行)...

Removing intermediate container cd49243be07b

Step 6 : EXPOSE 8080

---> Running in a4843a5a0c8e

---> c31129378fe8

Removing intermediate container a4843a5a0c8e

Successfully built c31129378fe8

# 第二次編譯速度會比較快，因為使用了 cache

mtchang@mt ~/SCM_code/docker/apdemo $ vim Dockerfile

mtchang@mt ~/SCM_code/docker/apdemo $ sudo docker build -t mtchang/apdemo .

Sending build context to Docker daemon 2.048 kB

Sending build context to Docker daemon

Step 0 : FROM ubuntu:latest

---> 5ba9dab47459

Step 1 : MAINTAINER mtchang

---> Using cache

---> 6c304964c942

Step 2 : ENV DEBIAN_FRONTEND noninteractive

---> Using cache

---> 4eb8188f88d7

---> Using cache

---> b0d088b36fe3

Step 4 : ENV PHP_UPLOAD_MAX_FILESIZE 10M

---> Using cache

---> 61e966ed8a2d

Step 5 : ENV PHP_POST_MAX_SIZE 10M

---> Using cache

---> 431d2a1cc310

Successfully built 431d2a1cc310

# 建立的影像檔案 mtchang/apdemo

mtchang@mt ~/SCM_code/docker/apdemo $ sudo docker images

REPOSITORY TAG IMAGE ID CREATED VIRTUAL SIZE

mtchang/apdemo latest 431d2a1cc310 14 minutes ago 426 MB

mtchang@mt ~/SCM_code/docker/apdemo $ sudo docker login

Username (mtchang):

# 可以單獨將這個檔案 push 到 docker hub 上面

mtchang@mt ~/SCM_code/docker/apdemo $ sudo docker push mtchang/apdemo

The push refers to a repository [mtchang/apdemo] (len: 1)

Sending image list

Pushing repository mtchang/apdemo (1 tags)

511136ea3c5a: Image already pushed, skipping

27d47432a69b: Image already pushed, skipping

5f92234dcf1e: Image already pushed, skipping

51a9c7c1f8bb: Image already pushed, skipping

5ba9dab47459: Image already pushed, skipping

6c304964c942: Image already pushed, skipping

4eb8188f88d7: Image already pushed, skipping

b0d088b36fe3: Image already pushed, skipping

61e966ed8a2d: Image already pushed, skipping

431d2a1cc310: Image already pushed, skipping

Pushing tag for rev [431d2a1cc310] on {https://cdn-registry-1.docker.io/v1/repositories/mtchang/apdemo/tags/latest}

# 以上為依據 dockerfile 的建立方法，但是產生的檔案只有本機可以使用。 push 到 docker hub 仍是影像檔案型態，使用者看不到你的 dockerfile 。

(2) 配合 github 的 dockerfile 建立

Docker hub 可以從 github 的儲存庫中，依據 Dockerfile 的內容自動建立影像檔案。

所以請先在 github 中建立一個 Dockerfile 檔案, README 有則是最好。

在 Docker HUB 內建立一個 REPOS 選擇 Github 的儲存庫。

在 docker hub 內選擇 automated Build 選項。

把 Active 打勾，並確認路徑是否正確。

按下 save and trigger build 就會自動建立 dockerfile 檔案了。

(3) 使用及測試

mtchang@mt ~/SCM_code/docker/apdemo $ sudo docker pull mtchang/apdemo

Pulling repository mtchang/apdemo

d0611a67283c: Download complete

d0611a67283c: Pulling image (latest) from mtchang/apdemo

fa4fd76b09ce: Download complete

1c8294cc5160: Download complete

117ee323aaa9: Download complete

2d24f826cb16: Download complete

d5f32e0f2638: Download complete

f6b232724428: Download complete

a392b7a15278: Download complete

ad48e990d540: Download complete

Status: Downloaded newer image for mtchang/apdemo:latest

mtchang@mt ~/SCM_code/docker/apdemo $ sudo docker images

REPOSITORY TAG IMAGE ID CREATED VIRTUAL SIZE

mtchang/apdemo latest d0611a67283c 17 minutes ago 425.9 MB

mtchang@mt ~/SCM_code/docker/apdemo $ sudo docker run -i -t -p 8080:80 mtchang/apdemo/bin/bash

root@c88dac59dbab:/# ifconfig

eth0 Link encap:Ethernet HWaddr 02:42:ac:11:00:08

inet addr:172.17.0.8 Bcast:0.0.0.0 Mask:255.255.0.0

inet6 addr: fe80::42:acff:fe11:8/64 Scope:Link

UP BROADCAST RUNNING MTU:1500 Metric:1

RX packets:8 errors:0 dropped:0 overruns:0 frame:0

TX packets:8 errors:0 dropped:0 overruns:0 carrier:0

collisions:0 txqueuelen:0

RX bytes:648 (648.0 B) TX bytes:648 (648.0 B)

lo Link encap:Local Loopback

inet addr:127.0.0.1 Mask:255.0.0.0

inet6 addr: ::1/128 Scope:Host

UP LOOPBACK RUNNING MTU:65536 Metric:1

RX packets:0 errors:0 dropped:0 overruns:0 frame:0

TX packets:0 errors:0 dropped:0 overruns:0 carrier:0

collisions:0 txqueuelen:0

RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)

root@c88dac59dbab:/# /etc/init.d/apache2 restart

* Restarting web server apache2

# Docker HOST 上面看到的 iptables 狀況

mt ~ # iptables -L -n -t nat

Chain PREROUTING (policy ACCEPT)