Merge pull request #570 from djdembeck/patch-1

Image uses 20.04 now

README.md

@@ -87,7 +87,7 @@ You can configure the stock `ubuntu` image yourself from your Dockerfile, so why
 
 | Component        | Why is it included? / Remarks |
 | ---------------- | ------------------- |
-| Ubuntu 18.04 LTS | The base system. |
+| Ubuntu 20.04 LTS | The base system. |
 | A **correct** init process | _Main article: [Docker and the PID 1 zombie reaping problem](http://blog.phusion.nl/2015/01/20/docker-and-the-pid-1-zombie-reaping-problem/)._ <br><br>According to the Unix process model, [the init process](https://en.wikipedia.org/wiki/Init) -- PID 1 -- inherits all [orphaned child processes](https://en.wikipedia.org/wiki/Orphan_process) and must [reap them](https://en.wikipedia.org/wiki/Wait_(system_call)). Most Docker containers do not have an init process that does this correctly. As a result, their containers become filled with [zombie processes](https://en.wikipedia.org/wiki/Zombie_process) over time. <br><br>Furthermore, `docker stop` sends SIGTERM to the init process, which stops all services. Unfortunately most init systems don't do this correctly within Docker since they're built for hardware shutdowns instead. This causes processes to be hard killed with SIGKILL, which doesn't give them a chance to correctly deinitialize things. This can cause file corruption. <br><br>Baseimage-docker comes with an init process `/sbin/my_init` that performs both of these tasks correctly. |
 | Fixes APT incompatibilities with Docker | See https://github.com/dotcloud/docker/issues/1024. |
 | syslog-ng | A syslog daemon is necessary so that many services - including the kernel itself - can correctly log to /var/log/syslog. If no syslog daemon is running, a lot of important messages are silently swallowed. <br><br>Only listens locally. All syslog messages are forwarded to "docker logs".<br><br>Why syslog-ng?<br>I've had bad experience with rsyslog. I regularly run into bugs with rsyslog, and once in a while it takes my log host down by entering a 100% CPU loop in which it can't do anything. Syslog-ng seems to be much more stable. |

README_ZH_cn_.md

@@ -82,7 +82,7 @@ Baseimage-docker让这一切完美。在"内容"部分描述了所有这些修
 
 | 模块        | 为什么包含这些？以及备注 |
 | ---------------- | ------------------- |
-| Ubuntu 18.04 LTS | 基础系统。 |
+| Ubuntu 20.04 LTS | 基础系统。 |
 | 一个**正确**的初始化进程  | *主要文章：[Docker和PID 1 僵尸进程回收问题](http://blog.phusion.nl/2015/01/20/docker-and-the-pid-1-zombie-reaping-problem/)*<br/><br/>根据Unix进程模型，[初始化进程](https://en.wikipedia.org/wiki/Init) -- PID 1 -- 继承了所有[孤立的子进程](https://en.wikipedia.org/wiki/Orphan_process)，并且必须[进行回收](https://en.wikipedia.org/wiki/Wait_(system_call))。大多数Docker容器没有一个初始化进程可以正确的完成此操作，随着时间的推移会导致他们的容器出现了大量的[僵尸进程](https://en.wikipedia.org/wiki/Zombie_process)。<br/><br/>而且，`docker stop`发送SIGTERM信号给初始化进程，照理说此信号应该可以停止所有服务。不幸的是由于它们对硬件进行了关闭操作，导致Docker内的大多数初始化系统没有正确执行。这会导致进程强行被SIGKILL信号关闭，从而丧失了一个正确取消初始化设置的机会。这会导致文件损坏。<br/><br/>Baseimage-docker配有一个名为`/sbin/my_init`的初始化进程来同时正确的完成这些任务。 |
 | 修复了APT与Docker不兼容的问题 | 详情参见：https://github.com/dotcloud/docker/issues/1024 。 |
 | syslog-ng | 对于很多服务－包括kernel自身，都需要一个syslog后台进程，以便可以正确的将log输出到/var/log/syslog中。如果没有运行syslog后台进程，很多重要的信息就会默默的丢失了。<br/><br/>只对本地进行监听。所有syslog信息会被转发给“docker logs”。 |

README_zh_tw.md

@@ -82,7 +82,7 @@ Baseimage-docker讓這一切完美。在"內容"部分描述了所有這些修
 
 | 模塊        | 爲什麼包含這些？以及備註 |
 | ---------------- | ------------------- |
-| Ubuntu 18.04 LTS | 基礎系統。 |
+| Ubuntu 20.04 LTS | 基礎系統。 |
 | 一個**正確**的初始化行程  | *主要文章：[Docker和PID 1 殭屍行程回收問題](http://blog.phusion.nl/2015/01/20/docker-and-the-pid-1-zombie-reaping-problem/)*<br/><br/>根據Unix行程模型，[初始化行程](https://en.wikipedia.org/wiki/Init) -- PID 1 -- 繼承了所有[孤立的子行程](https://en.wikipedia.org/wiki/Orphan_process)，並且必須[進行回收](https://en.wikipedia.org/wiki/Wait_(system_call))。大多數Docker容器沒有一個初始化行程可以正確的完成此操作，隨着時間的推移會導致他們的容器出現了大量的[殭屍行程](https://en.wikipedia.org/wiki/Zombie_process)。<br/><br/>而且，`docker stop`發送SIGTERM信號給初始化行程，照理說此信號應該可以停止所有服務。不幸的是由於它們對硬體進行了關閉操作，導致Docker內的大多數初始化系統沒有正確執行。這會導致行程強行被SIGKILL信號關閉，從而喪失了一個正確取消初始化設置的機會。這會導致文件損壞。<br/><br/>Baseimage-docker配有一個名爲`/sbin/my_init`的初始化行程來同時正確的完成這些任務。 |
 | 修復了APT與Docker不兼容的問題 | 詳情參見：https://github.com/dotcloud/docker/issues/1024 。 |
 | syslog-ng | 對於很多服務－包括kernel自身，都需要一個syslog後臺行程，以便可以正確的將log輸出到/var/log/syslog中。如果沒有運行syslog後臺行程，很多重要的信息就會默默的丟失了。<br/><br/>只對本地進行監聽。所有syslog信息會被轉發給“docker logs”。 |