大多dockerfile在build的时候遇到问题之后我先注释掉出问题的那一步，然后先build出一个出问题之前的镜像，run起来，进入容器实地手动的看下问题所在
时间同步问题和编码问题作为最最基础的环境问题，值得深入下
编码问题
alpine 编码
alpine对中文友好，自带en_US.UTF-8编码，如下
root@pa6:~# docker run -tid --name test_alpine alpine:latest /bin/sh
77e25fe295819f387409691726e248a9992c1c38cd861559962ecafb0b058089
root@pa6:~# docker exec -ti test_alpine /bin/sh
/ # 汉字测试
/bin/sh: 汉字测试: not found
解决方案
只需要在Dockerfile指定下
ENV LANG=en_US.UTF-8 \
LC_ALL=en_US.UTF-8
ubuntu 编码
没有en_US.UTF-8编码，意味着不能输入和输出中文，而我们的程序大多是在和中文打交道
root@pa6:~# docker run -tid --name test_ubuntu ubuntu:latest /bin/sh
084c690730d4fef12ab74bde7e249ed4668354c2928b9df2d33f781eaafb0b1c
root@pa6:~# docker exec -ti test_ubuntu /bin/bash
root@084c690730d4:/# locale -a
C
C.UTF-8
POSIX
解决方案
需要先安装locales命令
RUN apt-get update \
&& apt-get -y install locales \
&& locale-gen en_US.UTF-8
ENV LANG=en_US.UTF-8 \
LC_ALL=en_US.UTF-8
时间问题
大多数分布式程序的运行，是建立在时间同步的基础上
线上容器手动同步时间(example)
一次在ubuntu为base的容器上的时间同步过程
root@a072a5b0a5c4:/# dpkg-reconfigure tzdata
debconf: unable to initialize frontend: Dialog
debconf: (No usable dialog-like program is installed, so the dialog based frontend cannot be used. at /usr/share/perl5/Debconf/FrontEnd/Dialog.pm line 76.)
debconf: falling back to frontend: Readline
debconf: unable to initialize frontend: Readline
debconf: (Can't locate Term/ReadLine.pm in @INC (you may need to install the Term::ReadLine module) (@INC contains: /etc/perl /usr/local/lib/x86_64-linux-gnu/perl/5.22.1 /usr/local/share/perl/5.22.1 /usr/lib/x86_64-linux-gnu/perl5/5.22 /usr/share/perl5 /usr/lib/x86_64-linux-gnu/perl/5.22 /usr/share/perl/5.22 /usr/local/lib/site_perl /usr/lib/x86_64-linux-gnu/perl-base .) at /usr/share/perl5/Debconf/FrontEnd/Readline.pm line 7.)
debconf: falling back to frontend: Teletype
Configuring tzdata
------------------
Please select the geographic area in which you live. Subsequent configuration questions will narrow this down by presenting a list of cities, representing the time
zones in which they are located.
1. Africa 3. Antarctica 5. Arctic Ocean 7. Atlantic Ocean 9. Indian Ocean 11. System V timezones 13. None of the above
2. America 4. Australia 6. Asia 8. Europe 10. Pacific Ocean 12. US
Geographic area: 6
Please select the city or region corresponding to your time zone.
1. Aden 11. Baku 21. Damascus 31. Hong_Kong 41. Kashgar 51. Makassar 61. Pyongyang 71. Singapore 81. Ujung_Pandang
2. Almaty 12. Bangkok 22. Dhaka 32. Hovd 42. Kathmandu 52. Manila 62. Qatar 72. Srednekolymsk 82. Ulaanbaatar
3. Amman 13. Barnaul 23. Dili 33. Irkutsk 43. Khandyga 53. Muscat 63. Qostanay 73. Taipei 83. Urumqi
4. Anadyr 14. Beirut 24. Dubai 34. Istanbul 44. Kolkata 54. Nicosia 64. Qyzylorda 74. Tashkent 84. Ust-Nera
5. Aqtau 15. Bishkek 25. Dushanbe 35. Jakarta 45. Krasnoyarsk 55. Novokuznetsk 65. Rangoon 75. Tbilisi 85. Vientiane
6. Aqtobe 16. Brunei 26. Famagusta 36. Jayapura 46. Kuala_Lumpur 56. Novosibirsk 66. Riyadh 76. Tehran 86. Vladivostok
7. Ashgabat 17. Chita 27. Gaza 37. Jerusalem 47. Kuching 57. Omsk 67. Sakhalin 77. Tel_Aviv 87. Yakutsk
8. Atyrau 18. Choibalsan 28. Harbin 38. Kabul 48. Kuwait 58. Oral 68. Samarkand 78. Thimphu 88. Yangon
9. Baghdad 19. Chongqing 29. Hebron 39. Kamchatka 49. Macau 59. Phnom_Penh 69. Seoul 79. Tokyo 89. Yekaterinburg
10. Bahrain 20. Colombo 30. Ho_Chi_Minh 40. Karachi 50. Magadan 60. Pontianak 70. Shanghai 80. Tomsk 90. Yerevan
Time zone: 70
Current default time zone: 'Asia/Shanghai'
Local time is now: Mon May 20 14:10:26 CST 2019.
Universal Time is now: Mon May 20 06:10:26 UTC 2019.
root@a072a5b0a5c4:/# date #时间正确
Mon May 20 14:10:30 CST 2019
ubuntu上的时间
/etc/localtime本地时间/etc/timezone时区
系统会默认读取/etc/timezone以确定系统的时区
/etc/localtime的软连接是/usr/share/zoneinfo/localtime
以下是我在传统主机上查看所得
root@pa6:~# ll /usr/share/zoneinfo/localtime
lrwxrwxrwx 1 root root 14 Nov 10 2017 /usr/share/zoneinfo/localtime -> /etc/localtime
dpkg-reconfigure -f noninteractive 免交互设置时间，其实一般遇到这种问题，一查一个准，准有免交互解决方案
解决方案
ARG TZ="Asia/Shanghai"
ENV TZ ${TZ}
ADD Shanghai /etc/localtime # shanghai是主机上的“shanghai“ 文件
RUN apt-get -y install tzdata && echo 'Asia/Shanghai' >/etc/timezone && dpkg-reconfigure -f noninteractive tzdata
alpine上的时间
alpine自动读取/etc/timezone指定的时区并切换
解决方案
ARG TZ="Asia/Shanghai"
ENV TZ ${TZ}
ADD Shanghai /etc/localtime # shanghai是主机上的“shanghai“ 文件
RUN apk add --no-cache tzdata && echo 'Asia/Shanghai' >/etc/timezone
好了，到这里我就有点爱alpine了，尽管她不久前刚刚出了安全漏洞事件