mirror of
https://github.com/LCTT/TranslateProject.git
synced 2026-08-23 04:03:29 +08:00
Merge remote-tracking branch 'LCTT/master'
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Xingyu Wang
@@ -1,31 +1,31 @@
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[#]: collector: (lujun9972)
|
||||
[#]: translator: (HankChow)
|
||||
[#]: reviewer: ( )
|
||||
[#]: publisher: ( )
|
||||
[#]: url: ( )
|
||||
[#]: reviewer: (wxy)
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||||
[#]: publisher: (wxy)
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||||
[#]: url: (https://linux.cn/article-11696-1.html)
|
||||
[#]: subject: (3 easy steps to update your apps to Python 3)
|
||||
[#]: via: (https://opensource.com/article/19/12/update-apps-python-3)
|
||||
[#]: author: (Seth Kenlon https://opensource.com/users/seth)
|
||||
|
||||
将你的应用迁移到 Python 3 的三个步骤
|
||||
======
|
||||
Python 2 气数将尽，是时候将你的项目从 Python 2 迁移到 Python 3 了。
|
||||
|
||||
![Hands on a keyboard with a Python book ][1]
|
||||
> Python 2 气数将尽，是时候将你的项目从 Python 2 迁移到 Python 3 了。
|
||||
|
||||
Python 2.x 很快就要[失去官方支持][2]了，尽管如此，从 Python 2 迁移到 Python 3 却并没有想象中那么难。我在上周用了一个晚上的时间将一个 3D 渲染器及其对应的 [PySide][3] 迁移到 Python 3，回想起来，尽管在迁移过程中无可避免地会遇到一些牵一发而动全身的修改，但整个过程相比起痛苦的重构来说简直是出奇地简单。
|
||||
|
||||
|
||||
Python 2.x 很快就要[失去官方支持][2]了，尽管如此，从 Python 2 迁移到 Python 3 却并没有想象中那么难。我在上周用了一个晚上的时间将一个 3D 渲染器的前端代码及其对应的 [PySide][3] 迁移到 Python 3，回想起来，尽管在迁移过程中无可避免地会遇到一些牵一发而动全身的修改，但整个过程相比起痛苦的重构来说简直是出奇地简单。
|
||||
|
||||
每个人都别无选择地有各种必须迁移的原因：或许是觉得已经拖延太久了，或许是依赖了某个在 Python 2 下不再维护的模块。但如果你仅仅是想通过做一些事情来对开源做贡献，那么把一个 Python 2 应用迁移到 Python 3 就是一个简单而又有意义的做法。
|
||||
|
||||
无论你从 Python 2 迁移到 Python 3 的原因是什么，这都是一项重要的任务。按照以下三个步骤，可以让你把任务完成得更加清晰。
|
||||
|
||||
### 1\. 使用 2to3
|
||||
### 1、使用 2to3
|
||||
|
||||
从几年前开始，Python 在你或许还不知道的情况下就已经自带了一个名叫 [2to3][4] 的脚本，它可以帮助你实现大部分代码从 Python 2 到 Python 3 的自动转换。
|
||||
|
||||
下面是一段使用 Python 2.6 编写的代码：
|
||||
|
||||
|
||||
```
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#!/usr/bin/env python
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# -*- coding: utf-8 -*-
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@@ -39,12 +39,12 @@ print ord(mystring[-1])
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```
|
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$ 2to3 example.py
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RefactoringTool: Refactored example.py
|
||||
\--- example.py (original)
|
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+++ example.py (refactored)
|
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--- example.py (original)
|
||||
+++ example.py (refactored)
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||||
@@ -1,5 +1,5 @@
|
||||
#!/usr/bin/env python
|
||||
# -*- coding: utf-8 -*-
|
||||
|
||||
#!/usr/bin/env python
|
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# -*- coding: utf-8 -*-
|
||||
|
||||
-mystring = u'abcdé'
|
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-print ord(mystring[-1])
|
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+mystring = 'abcdé'
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@@ -53,8 +53,7 @@ RefactoringTool: Files that need to be modified:
|
||||
RefactoringTool: example.py
|
||||
```
|
||||
|
||||
在默认情况下，2to3 只会对迁移到 Python 3 时必须作出修改的代码进行标示，在输出结果中显示的 Python 3 代码是直接可用的，但你可以在 2to3 加上 `-w` 或者 `--write` 参数，这样它就可以直接按照给出的方案修改你的 Python 2 代码文件了。
|
||||
|
||||
在默认情况下，`2to3` 只会对迁移到 Python 3 时必须作出修改的代码进行标示，在输出结果中显示的 Python 3 代码是直接可用的，但你可以在 2to3 加上 `-w` 或者 `--write` 参数，这样它就可以直接按照给出的方案修改你的 Python 2 代码文件了。
|
||||
|
||||
```
|
||||
$ 2to3 -w example.py
|
||||
@@ -63,17 +62,16 @@ RefactoringTool: Files that were modified:
|
||||
RefactoringTool: example.py
|
||||
```
|
||||
|
||||
2to3 脚本不仅仅对单个文件有效，你还可以把它用于一个目录下的所有 Python 文件，同时它也会递归地对所有子目录下的 Python 文件都生效。
|
||||
`2to3` 脚本不仅仅对单个文件有效，你还可以把它用于一个目录下的所有 Python 文件，同时它也会递归地对所有子目录下的 Python 文件都生效。
|
||||
|
||||
### 2\. 使用 Pylint 或 Pyflakes
|
||||
### 2、使用 Pylint 或 Pyflakes
|
||||
|
||||
有一些不良的代码习惯在 Python 2 下运行是没有异常的，在 Python 3 下运行则会或多或少报出错误，并且这些代码无法通过语法转换来修复，所以 2to3 对它们没有效果，但一旦使用 Python 3 来运行就会产生报错。
|
||||
有一些不良的代码在 Python 2 下运行是没有异常的，在 Python 3 下运行则会或多或少报出错误，这种情况并不鲜见。因为这些不良代码无法通过语法转换来修复，所以 `2to3` 对它们没有效果，但一旦使用 Python 3 来运行就会产生报错。
|
||||
|
||||
对于这种情况，你需要使用 [Pylint][5]、[Pyflakes][6]（或封装好的 [flake8][7]）这类工具。其中我更喜欢 Pyflakes，它会忽略代码风格上的差异，在这一点上它和 Pylint 不同。尽管代码优美是 Python 的一大特点，但在代码迁移的层面上，“让代码功能保持一致”无疑比“让代码风格保持一致”重要得多/
|
||||
要找出这种问题，你需要使用 [Pylint][5]、[Pyflakes][6]（或 [flake8][7] 封装器）这类工具。其中我更喜欢 Pyflakes，它会忽略代码风格上的差异，在这一点上它和 Pylint 不同。尽管代码优美是 Python 的一大特点，但在代码迁移的层面上，“让代码功能保持一致”无疑比“让代码风格保持一致”重要得多。
|
||||
|
||||
以下是 Pyflakes 的输出样例：
|
||||
|
||||
|
||||
```
|
||||
$ pyflakes example/maths
|
||||
example/maths/enum.py:19: undefined name 'cmp'
|
||||
@@ -87,7 +85,6 @@ example/maths/enum.py:208: local variable 'e' is assigned to but never used
|
||||
|
||||
值得注意的是第 19 行这个容易产生误导的错误。从输出来看你可能会以为 `cmp` 是一个在使用前未定义的变量，实际上 `cmp` 是 Python 2 的一个内置函数，而它在 Python 3 中被移除了。而且这段代码被放在了 `try` 语句块中，除非认真检查这段代码的输出值，否则这个问题很容易被忽略掉。
|
||||
|
||||
|
||||
```
|
||||
try:
|
||||
result = cmp(self.index, other.index)
|
||||
@@ -99,13 +96,12 @@ example/maths/enum.py:208: local variable 'e' is assigned to but never used
|
||||
|
||||
在代码迁移过程中，你会发现很多原本在 Python 2 中能正常运行的函数都发生了变化，甚至直接在 Python 3 中被移除了。例如 PySide 的绑定方式发生了变化、`importlib` 取代了 `imp` 等等。这样的问题只能见到一个解决一个，而涉及到的功能需要重构还是直接放弃，则需要你自己权衡。但目前来说，大多数问题都是已知的，并且有[完善的文档记录][8]。所以难的不是修复问题，而是找到问题，从这个角度来说，使用 Pyflake 是很有必要的。
|
||||
|
||||
### 3\. 修复被破坏的 Python 2 代码
|
||||
### 3、修复被破坏的 Python 2 代码
|
||||
|
||||
尽管 2to3 脚本能够帮助你把代码修改成兼容 Python 3 的形式，但对于一个完整的代码库，它就显得有点无能为力了，因为一些老旧的代码在 Python 3 中可能需要不同的结构来表示。在这样的情况下，只能人工进行修改。
|
||||
尽管 `2to3` 脚本能够帮助你把代码修改成兼容 Python 3 的形式，但对于一个完整的代码库，它就显得有点无能为力了，因为一些老旧的代码在 Python 3 中可能需要不同的结构来表示。在这样的情况下，只能人工进行修改。
|
||||
|
||||
例如以下代码在 Python 2.6 中可以正常运行：
|
||||
|
||||
|
||||
```
|
||||
class CLOCK_SPEED:
|
||||
TICKS_PER_SECOND = 16
|
||||
@@ -116,8 +112,7 @@ class FPS:
|
||||
STATS_UPDATE_FREQUENCY = CLOCK_SPEED.TICKS_PER_SECOND
|
||||
```
|
||||
|
||||
类似 2to3 和 Pyflakes 这些自动化工具并不能发现其中的问题，但如果上述代码使用 Python 3 来运行，解释器会认为 `CLOCK_SPEED.TICKS_PER_SECOND` 是未被明确定义的。因此就需要把代码改成面向对象的结构：
|
||||
|
||||
类似 `2to3` 和 Pyflakes 这些自动化工具并不能发现其中的问题，但如果上述代码使用 Python 3 来运行，解释器会认为 `CLOCK_SPEED.TICKS_PER_SECOND` 是未被明确定义的。因此就需要把代码改成面向对象的结构：
|
||||
|
||||
```
|
||||
class CLOCK_SPEED:
|
||||
@@ -131,7 +126,7 @@ class FPS:
|
||||
STATS_UPDATE_FREQUENCY = CLOCK_SPEED.TICKS_PER_SECOND()
|
||||
```
|
||||
|
||||
你也许会认为如果把 `TICKS_PER_SECOND()` 改写为一个构造函数能让代码看起来更加简洁，但这样就需要把这个方法的调用形式从 `CLOCK_SPEED.TICKS_PER_SECOND()` 改为 `CLOCK_SPEED()` 了，这样的改动或多或少会对整个库造成一些未知的影响。如果你对整个代码库的结构烂熟于心，那么你确实可以随心所欲地作出这样的修改。但我通常认为，只要我做出了修改，都可能会影响到其它代码中的至少三处地方，因此我更倾向于不使代码的结构发生改变。
|
||||
你也许会认为如果把 `TICKS_PER_SECOND()` 改写为一个构造函数（用 `__init__` 函数设置默认值）能让代码看起来更加简洁，但这样就需要把这个方法的调用形式从 `CLOCK_SPEED.TICKS_PER_SECOND()` 改为 `CLOCK_SPEED()` 了，这样的改动或多或少会对整个库造成一些未知的影响。如果你对整个代码库的结构烂熟于心，那么你确实可以随心所欲地作出这样的修改。但我通常认为，只要我做出了修改，都可能会影响到其它代码中的至少三处地方，因此我更倾向于不使代码的结构发生改变。
|
||||
|
||||
### 坚持信念
|
||||
|
||||
@@ -146,14 +141,14 @@ via: https://opensource.com/article/19/12/update-apps-python-3
|
||||
作者：[Seth Kenlon][a]
|
||||
选题：[lujun9972][b]
|
||||
译者：[HankChow](https://github.com/HankChow)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
校对：[wxy](https://github.com/wxy)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]: https://opensource.com/users/seth
|
||||
[b]: https://github.com/lujun9972
|
||||
[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/python-programming-code-keyboard.png?itok=fxiSpmnd "Hands on a keyboard with a Python book "
|
||||
[2]: https://opensource.com/article/19/11/end-of-life-python-2
|
||||
[2]: https://linux.cn/article-11629-1.html
|
||||
[3]: https://pypi.org/project/PySide/
|
||||
[4]: https://docs.python.org/3.1/library/2to3.html
|
||||
[5]: https://opensource.com/article/19/10/python-pylint-introduction
|
||||
@@ -1,24 +1,26 @@
|
||||
[#]: collector: (lujun9972)
|
||||
[#]: translator: (geekpi)
|
||||
[#]: reviewer: ( )
|
||||
[#]: publisher: ( )
|
||||
[#]: url: ( )
|
||||
[#]: reviewer: (wxy)
|
||||
[#]: publisher: (wxy)
|
||||
[#]: url: (https://linux.cn/article-11698-1.html)
|
||||
[#]: subject: (How to configure Openbox for your Linux desktop)
|
||||
[#]: via: (https://opensource.com/article/19/12/openbox-linux-desktop)
|
||||
[#]: author: (Seth Kenlon https://opensource.com/users/seth)
|
||||
|
||||
如何为 Linux 桌面配置 Openbox
|
||||
======
|
||||
本文是 24 天 Linux 桌面特别系列的一部分。Openbox 窗口管理器占用很小的系统资源、易于配置、使用愉快。
|
||||
![open with sky and grass][1]
|
||||
|
||||
你可能不知道使用过 [Openbox][2] 桌面：尽管 Openbox 本身是一个出色的窗口管理器，但它还是 LXDE 和 LXQT 等桌面环境的窗口管理器“引擎”，它甚至可以管理 KDE 和 GNOME。除了作为多个桌面的基础之外，Openbox 可以说是最简单的窗口管理器之一，可以为那些不想学习所有配置选项的人配置。通过使用基于菜单的 **obconf** 的配置应用，可以像在 GNOME 或 KDE 这样的完整桌面中一样轻松地设置所有常用首选项。
|
||||
> 本文是 24 天 Linux 桌面特别系列的一部分。Openbox 窗口管理器占用很小的系统资源、易于配置、使用愉快。
|
||||
|
||||
|
||||
|
||||
你可能不知道你使用过 [Openbox][2] 桌面：尽管 Openbox 本身是一个出色的窗口管理器，但它还是 LXDE 和 LXQT 等桌面环境的窗口管理器“引擎”，它甚至可以管理 KDE 和 GNOME。除了作为多个桌面的基础之外，Openbox 可以说是最简单的窗口管理器之一，可以为那些不想学习那么多配置选项的人配置。通过使用基于菜单的 obconf 的配置应用，可以像在 GNOME 或 KDE 这样的完整桌面中一样轻松地设置所有常用首选项。
|
||||
|
||||
### 安装 Openbox
|
||||
|
||||
你可能会在 Linux 发行版的软件仓库中找到 Openbox，但也可以在 [Openbox.org][3] 中找到它。如果你已经在运行其他桌面，那么可以安全地在同一系统上安装 Openbox，因为 Openbox 除了几个配置面板之外，不包括任何捆绑的应用。
|
||||
你可能会在 Linux 发行版的软件仓库中找到 Openbox，也可以在 [Openbox.org][3] 中找到它。如果你已经在运行其他桌面，那么可以安全地在同一系统上安装 Openbox，因为 Openbox 除了几个配置面板之外，不包括任何捆绑的应用。
|
||||
|
||||
安装后，退出当前桌面会话，以便你可以登录 Openbox 桌面。默认情况下，会话管理器（KDM、GDM、LightDM 或 XDM，这取决于你的设置）将继续登录到以前的桌面，因此你必须在登录之前覆盖该桌面。
|
||||
安装后，退出当前桌面会话，以便你可以登录 Openbox 桌面。默认情况下，会话管理器（KDM、GDM、LightDM 或 XDM，这取决于你的设置）将继续登录到以前的桌面，因此你必须在登录之前覆盖该选择。
|
||||
|
||||
要使用 GDM 覆盖它：
|
||||
|
||||
@@ -30,17 +32,17 @@
|
||||
|
||||
### 配置 Openbox 桌面
|
||||
|
||||
默认情况下，Openbox 包含 **obconf** 应用，你可以使用它来选择和安装主题，修改鼠标行为，设置桌面首选项等。你可能会在仓库中发现其他配置应用，如 **obmenu** ，用于配置窗口管理器的其他部分。
|
||||
默认情况下，Openbox 包含 obconf 应用，你可以使用它来选择和安装主题、修改鼠标行为、设置桌面首选项等。你可能会在仓库中发现其他配置应用，如 obmenu，用于配置窗口管理器的其他部分。
|
||||
|
||||
![Openbox Obconf configuration application][6]
|
||||
|
||||
建立你自己的桌面体验相对容易。它有一些所有常见的桌面组件，例如系统托盘 [stalonetray][7]、任务栏 [Tint2][8] 或 [Xfce4-panel][9] 等几乎你能想到的。任意组合应用，直到拥有梦想的开源桌面为止。
|
||||
构建你自己的桌面环境相对容易。它有一些所有常见的桌面组件，例如系统托盘 [stalonetray][7]、任务栏 [Tint2][8] 或 [Xfce4-panel][9] 等几乎你能想到的。任意组合应用，直到拥有梦想的开源桌面为止。
|
||||
|
||||
![Openbox][10]
|
||||
|
||||
### 为何使用 Openbox
|
||||
|
||||
Openbox 占用很小的系统资源、易于配置、使用愉快。它基本不会弹出，因此会是一个容易熟悉的系统。你永远不会知道你面前的桌面秘密使用了 Openbox 作为窗口管理器（知道如何自定义它会不会很高兴？）。如果开源吸引你，那么试试看 Openbox。
|
||||
Openbox 占用的系统资源很小、易于配置、使用起来很愉悦。它基本不会让你感觉到阻碍，会是一个容易熟悉的系统。你永远不会知道你面前的桌面环境秘密使用了 Openbox 作为窗口管理器（知道如何自定义它会不会很高兴？）。如果开源吸引你，那么试试看 Openbox。
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
@@ -49,7 +51,7 @@ via: https://opensource.com/article/19/12/openbox-linux-desktop
|
||||
作者：[Seth Kenlon][a]
|
||||
选题：[lujun9972][b]
|
||||
译者：[geekpi](https://github.com/geekpi)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
校对：[wxy](https://github.com/wxy)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
@@ -0,0 +1,82 @@
|
||||
[#]: collector: (lujun9972)
|
||||
[#]: translator: ( )
|
||||
[#]: reviewer: ( )
|
||||
[#]: publisher: ( )
|
||||
[#]: url: ( )
|
||||
[#]: subject: (Space-data-as-a-service prepares to take off)
|
||||
[#]: via: (https://www.networkworld.com/article/3489484/space-data-as-a-service-prepares-to-take-off.html)
|
||||
[#]: author: (Patrick Nelson https://www.networkworld.com/author/Patrick-Nelson/)
|
||||
|
||||
Space-data-as-a-service prepares to take off
|
||||
======
|
||||
Development of IoT services in space will require ruggedized edge computing. OrbitsEdge, a vendor has announced a deal with HPE for development.
|
||||
REUTERS/Joe Skipper/File Photo
|
||||
|
||||
Upcoming space commercialization will require hardened edge-computing environments in a small footprint with robust links back to Earth, says vendor [OrbitsEdge][1], which recently announced that it had started collaborating with Hewlett Packard Enterprise on computing-in-orbit solutions.
|
||||
|
||||
OrbitsEdge says it’s the first to provide a commercial [data-center][2] environment for installing in orbit, and will be using HPE’s Edgeline Converged Edge System in a hardened, satellite [micro-data-center][3] platform that it’s selling called SatFrame.
|
||||
|
||||
[[Get regularly scheduled insights by signing up for Network World newsletters.]][4]
|
||||
|
||||
The idea is “to run analytics such as artificial intelligence (AI) on the vast amounts of data that will be created as space is commercialized,” says Barbara Stinnett, CEO of OrbitsEdge, in a [press release][5].
|
||||
|
||||
[][6]
|
||||
|
||||
BrandPost Sponsored by HPE
|
||||
|
||||
[Take the Intelligent Route with Consumption-Based Storage][6]
|
||||
|
||||
Combine the agility and economics of HPE storage with HPE GreenLake and run your IT department with efficiency.
|
||||
|
||||
### Why data in space?
|
||||
|
||||
[IoT][7] data collection along with analysis and experimental testing are two examples of space industrialization that the company gives as use cases for its micro-data center product. However, commercial use of space also includes imagery, communications, weather forecasting and navigation. Space tourism and commercial recovery of space resources, such as mined raw materials from asteroids are likely to be future space-uses, too.
|
||||
|
||||
Also, manufacturing – taking advantage of vacuums and zero-gravity environments – is among the economic activities that could take advantage of number crunching in orbit.
|
||||
|
||||
Additionally, [Cloud Constellation Corp., a company I wrote about in 2017, unrelated to OrbitsEdge or HPE, reckons highly sensitive data should be stored isolated][8] [in][8] [space][8]. That would be the “ultimate air-gap security,” it describes its [SpaceBelt][9] product.
|
||||
|
||||
### Why edge in space?
|
||||
|
||||
OrbitsEdge believes that data must be processed where it is collected, in space, in order to reduce transmission bottlenecks as streams are piped back to Earth stations. “Due to the new wave of low-cost commercial space activity, the bottleneck will get worse,” the company explains on its website.
|
||||
|
||||
What it means is that getting satellites into space is now cheap and is getting cheaper (due primarily to reusable rocket technology), but that there’s a problem getting the information back to traditional cloud environments on the surface of the Earth; there’s not enough backhaul data capacity, and that increases processing costs. Therefore, the cloud needs to move to the data-collection point: It’s “IoT above the cloud,” ObitsEdge cleverly taglines.
|
||||
|
||||
### How it works
|
||||
|
||||
Satellite-mounted solar arrays collect power from the sun. They fill batteries to be used when the satellite is in the shadow of Earth.
|
||||
|
||||
Cooling- and radiation-shielding protect a standard 5U, 19-inch server rack. There’s a separate rack for the avionics. Then integrated, traditional space-to-space, and space-to-ground radio communications handle the comms. Future-proofing is also considered: laser data pipes, too, could be supported, the company says.
|
||||
|
||||
#### On Earth option
|
||||
|
||||
Interestingly, the company is also pitching its no-maintenance, low Earth orbit (LEO)-geared product as being suitable for terrestrial extreme environments, too. OrbitsEdge claims that SatFrame is robust enough for extreme chemical and temperature environments on Earth. Upselling, it also says that one could combine two micro-data centers: a LEO SatFrame running HPE’s Edgeline, communicating with another one in an extreme on-Earth location—one at the Poles, maybe.
|
||||
|
||||
“To keep up with the rate of change and the number of satellites being launched into low Earth orbit, new services have to be made available,” OrbitsEdge says. “Shipping data back to terrestrial clouds is impractical, however today it is the only choice,” it says.
|
||||
|
||||
Join the Network World communities on [Facebook][10] and [LinkedIn][11] to comment on topics that are top of mind.
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://www.networkworld.com/article/3489484/space-data-as-a-service-prepares-to-take-off.html
|
||||
|
||||
作者：[Patrick Nelson][a]
|
||||
选题：[lujun9972][b]
|
||||
译者：[译者ID](https://github.com/译者ID)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]: https://www.networkworld.com/author/Patrick-Nelson/
|
||||
[b]: https://github.com/lujun9972
|
||||
[1]: https://orbitsedge.com/
|
||||
[2]: https://www.networkworld.com/article/3223692/what-is-a-data-centerhow-its-changed-and-what-you-need-to-know.html
|
||||
[3]: https://www.networkworld.com/article/3445382/10-hot-micro-data-center-startups-to-watch.html
|
||||
[4]: https://www.networkworld.com/newsletters/signup.html
|
||||
[5]: https://orbitsedge.com/press-releases/f/orbitsedge-oem-agreement-with-hewlett-packard-enterprise
|
||||
[6]: https://www.networkworld.com/article/3440100/take-the-intelligent-route-with-consumption-based-storage.html?utm_source=IDG&utm_medium=promotions&utm_campaign=HPE20773&utm_content=sidebar ( Take the Intelligent Route with Consumption-Based Storage)
|
||||
[7]: https://www.networkworld.com/article/3207535/what-is-iot-the-internet-of-things-explained.html
|
||||
[8]: https://www.networkworld.com/article/3200242/data-should-be-stored-data-in-space-firm-says.html
|
||||
[9]: http://spacebelt.com/
|
||||
[10]: https://www.facebook.com/NetworkWorld/
|
||||
[11]: https://www.linkedin.com/company/network-world
|
||||
@@ -0,0 +1,68 @@
|
||||
[#]: collector: (lujun9972)
|
||||
[#]: translator: ( )
|
||||
[#]: reviewer: ( )
|
||||
[#]: publisher: ( )
|
||||
[#]: url: ( )
|
||||
[#]: subject: (Bamboo Systems redesigns server motherboards for greater performance)
|
||||
[#]: via: (https://www.networkworld.com/article/3490385/bamboo-systems-redesigns-server-motherboards-for-greater-performance.html)
|
||||
[#]: author: (Andy Patrizio https://www.networkworld.com/author/Andy-Patrizio/)
|
||||
|
||||
Bamboo Systems redesigns server motherboards for greater performance
|
||||
======
|
||||
Bamboo Systems, formerly Kaleao, claims its motherboard architecture is more power efficient than traditional designs that cater to x86 processors.
|
||||
Thinkstock
|
||||
|
||||
UK chip designer Kaleao has re-launched as Bamboo Systems with some pre-Series A funding and claims its [Arm][1]-based server chips will be considerably more power efficient than the competition.
|
||||
|
||||
[[Get regularly scheduled insights by signing up for Network World newsletters.]][2]
|
||||
|
||||
Bamboo is targeting x86 servers, which have a 95% market share, unlike Marvell with its [ThunderX2][3] and Ampere Systems with its [eMAG Arm processors][4]. The company argues that the two Arm processors are no different than x86.
|
||||
|
||||
“Marvell and Ampere are chip manufacturers that have built a chip to pretty much slot into the motherboard and chassis configuration that an Intel/AMD chip would fit into. They are therefore going head on against Intel/AMD as chip manufacturers – and history is showing, not creating a sustainable solution for the OEMs,” says John Goodacre, co-founder and chief scientific officer of Bamboo.
|
||||
|
||||
[][5]
|
||||
|
||||
BrandPost Sponsored by HPE
|
||||
|
||||
[Take the Intelligent Route with Consumption-Based Storage][5]
|
||||
|
||||
Combine the agility and economics of HPE storage with HPE GreenLake and run your IT department with efficiency.
|
||||
|
||||
The motherboard is changed, but the CPU and software layer are not. Currently the company is in the prototype stage. Its server is based on Samsung Arm Cortex-A57 design, so the CPU itself is not changed. Even though they have essentially thrown out traditional motherboard design, Goodacre said the software is fully compatible and will run unchanged. So Linux and Arm-based apps will all run.
|
||||
|
||||
Goodacre, a 17-year veteran of Arm and researcher at the University of Manchester working on exascale research projects, said just putting more cores in a die in a workstation designed system isn’t the most power efficient way to build scale out power efficient servers.
|
||||
|
||||
“We realized that the system architecture was where your power was consumed more than instruction set. There have been several Arm chips [in servers] and they show the difference in power efficiency in an Arm gives you a few tens of percent. There is very little power efficiency in Arm over x86,” he said.
|
||||
|
||||
What he noticed was that because of the motherboard and all of its ports, like USB and I/O, a lot of power was wasted on the motherboard resources. Kaleo, now Bamboo, redesigned the whole motherboard where things like I/O and memory are pooled, so doubling the processor count doesn’t require doubling of motherboards.
|
||||
|
||||
This means a shared infrastructure with pooling of non-CPU resources and NVMe to scale up storage. A 3U box can hold up to 192 eight-core servers, 42 U.2 SSDs and 192 directly attached SATA 6 drives.
|
||||
|
||||
“The concept of a motherboard is gone. Instead, you put the infrastructure to support processors. We build clusters of machines on boards where the infrastructure is shared across processor elements,” he said.
|
||||
|
||||
The result, he claims, is the Bamboo system can deliver the same amount of web traffic in 10x less server space for 5x less energy. “One rack of our stuff equals 10 racks of the competition,” said Goodacre.
|
||||
|
||||
Bamboo says it will announce more details in early January.
|
||||
|
||||
Join the Network World communities on [Facebook][6] and [LinkedIn][7] to comment on topics that are top of mind.
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://www.networkworld.com/article/3490385/bamboo-systems-redesigns-server-motherboards-for-greater-performance.html
|
||||
|
||||
作者：[Andy Patrizio][a]
|
||||
选题：[lujun9972][b]
|
||||
译者：[译者ID](https://github.com/译者ID)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]: https://www.networkworld.com/author/Andy-Patrizio/
|
||||
[b]: https://github.com/lujun9972
|
||||
[1]: https://www.networkworld.com/article/3306447/a-new-arm-based-server-processor-challenges-for-the-data-center.html
|
||||
[2]: https://www.networkworld.com/newsletters/signup.html
|
||||
[3]: https://www.networkworld.com/article/3271073/cavium-launches-thunderx2-arm-based-server-processors.html
|
||||
[4]: https://www.networkworld.com/article/3482248/ampere-preps-an-80-core-arm-processor-for-the-cloud.html
|
||||
[5]: https://www.networkworld.com/article/3440100/take-the-intelligent-route-with-consumption-based-storage.html?utm_source=IDG&utm_medium=promotions&utm_campaign=HPE20773&utm_content=sidebar ( Take the Intelligent Route with Consumption-Based Storage)
|
||||
[6]: https://www.facebook.com/NetworkWorld/
|
||||
[7]: https://www.linkedin.com/company/network-world
|
||||
124
sources/tech/20191218 How tracking pixels work.md
Normal file
124
sources/tech/20191218 How tracking pixels work.md
Normal file
@@ -0,0 +1,124 @@
|
||||
[#]: collector: (lujun9972)
|
||||
[#]: translator: ( )
|
||||
[#]: reviewer: ( )
|
||||
[#]: publisher: ( )
|
||||
[#]: url: ( )
|
||||
[#]: subject: (How tracking pixels work)
|
||||
[#]: via: (https://jvns.ca/blog/how-tracking-pixels-work/)
|
||||
[#]: author: (Julia Evans https://jvns.ca/)
|
||||
|
||||
How tracking pixels work
|
||||
======
|
||||
|
||||
I spent some time talking to a reporter yesterday about how advertisers track people on the internet. We had a really fun time looking at Firefox’s developer tools together (I’m not an internet privacy expert, but I do know how to use the network tab in developer tools!) and I learned a few things about how tracking pixels actually work in practice!
|
||||
|
||||
### the question: how does Facebook know that you went to Old Navy?
|
||||
|
||||
I often hear about this slightly creepy internet experience: you’re looking at a product online, and a day later see an ad for the same boots or whatever that you were looking at. This is called “retargeting”, but how does it actually work exactly in practice?
|
||||
|
||||
In this post we’ll experiment a bit and see exactly how Facebook can know what products you’ve looked at online! I’m using Facebook as an example in this blog post just because it’s easy to find websites with Facebook tracking pixels on them but of course almost every internet advertising company does this kind of tracking.
|
||||
|
||||
### the setup: allow third party trackers, turn off my adblocker
|
||||
|
||||
I use Firefox, and by default Firefox blocks a lot of this kind of tracking. So I needed to modify my Firefox privacy settings to get this tracking to work.
|
||||
|
||||
I changed my privacy settings from the default ([screenshot][1]) to a custom setting that allows third-party trackers ([screenshot][2]). I also disabled some privacy extensions I usually have running.
|
||||
|
||||
### tracking pixels: it’s not the gif, it’s the query parameters
|
||||
|
||||
A tracking pixel is a 1x1 gif that sites use to track you. By itself, obviously a tiny 1x1 gif doesn’t do too much. So how do tracking pixels track you? 2 ways:
|
||||
|
||||
1. Sites use the **query parameters** in the tracking pixel to add extra information like the URL of the page you’re visiting. So instead of just requesting `https://www.facebook.com/tr/` (which is a 44-byte 1x1 gif), it’ll request `https://www.facebook.com/tr/?the_website_you're_on`. (email marketers use similar tricks to figure out if you’ve opened an email, by giving the tracking pixel a unique URL)
|
||||
2. Sites send **cookies** with the tracking pixel so that they can tell that the person who visited oldnavy.com is the same as the person who’s using Facebook on the same computer.
|
||||
|
||||
|
||||
|
||||
### the Facebook tracking pixel on Old Navy’s website
|
||||
|
||||
To test this out, I went to look at a product on the Old Navy site with the URL [https://oldnavy.gap.com/browse/product.do?pid=504753002&cid=1125694&pcid=1135640&vid=1&grid=pds_0_109_1][3] (a “Soft-Brushed Plaid Topcoat for Men”).
|
||||
|
||||
When I did that, the Javascript running on that page (presumably [this code][4]) sent a request to facebook.com that looks like this in Developer tools: (I censored most of the cookie values because some of them are my login cookies :) )
|
||||
|
||||
![][5]
|
||||
|
||||
Let’s break down what’s happening:
|
||||
|
||||
1. My browser sends a request to ` https://www.facebook.com/tr/?id=937725046402747&ev=PageView&dl=https%3A%2F%2Foldnavy.gap.com%2Fbrowse%2Fproduct.do%3Fpid%3D504753002%26cid%3D1125694%26pcid%3Dxxxxxx0%26vid%3D1%26grid%3Dpds_0_109_1%23pdp-page-content&rl=https%3A%2F%2Foldnavy.gap.com%2Fbrowse%2Fcategory.do%3Fcid%3D1135640%26mlink%3D5155%2Cm_mts_a&if=false&ts=1576684838096&sw=1920&sh=1080&v=2.9.15&r=stable&a=tmtealium&ec=0&o=30&fbp=fb.1.1576684798512.1946041422&it=15xxxxxxxxxx4&coo=false&rqm=GET`
|
||||
2. With that request, it sends a cookie called `fr` which is set to `10oGXEcKfGekg67iy.AWVdJq5MG3VLYaNjz4MTNRaU1zg.Bd-kxt.KU.F36.0.0.Bd-kx6.` (which I guess is my Facebook ad tracking ID)
|
||||
|
||||
|
||||
|
||||
So the three most notable things that are being sent in the tracking pixel query string are:
|
||||
|
||||
* the page I visited: [https://oldnavy.gap.com/browse/product.do?pid=504753002&cid=1125694&pcid=1135640&vid=1&grid=pds_0_109_1#pdp-page-content][6]
|
||||
* the page that referred me to that page: [https://oldnavy.gap.com/browse/category.do?cid=1135640&mlink=5155,m_mts_a][7]
|
||||
* an identifier cookie for me: `10oGXEcKfGekg67iy.AWVdJq5MG3VLYaNjz4MTNRaU1zg.Bd-kxt.KU.F36.0.0.Bd-kx6.`
|
||||
|
||||
|
||||
|
||||
### now let’s visit Facebook!
|
||||
|
||||
Next, let’s visit Facebook, where I’m logged in. What cookies is my browser sending Facebook?
|
||||
|
||||
Unsurprisingly, it’s the same `fr` cookie from before: `10oGXEcKfGekg67iy.AWVdJq5MG3VLYaNjz4MTNRaU1zg.Bd-kxt.KU.F36.0.0.Bd-kx6.`. So Facebook now definitely knows that I (Julia Evans, the person with this Facebook account) visited the Old Navy website a couple of minutes ago and looked at a “Soft-Brushed Plaid Topcoat for Men”, because they can use that identifier to match up the data.
|
||||
|
||||
### these cookies are third-party cookies
|
||||
|
||||
The `fr` cookie that Facebook is using to track what websites I go to is called a “third party cookie”, because Old Navy’s website is using it to identify me to a third party (facebook.com). This is different from first-party cookies, which are used to keep you logged in.
|
||||
|
||||
Safari and Firefox both block many third-party cookies by default (which is why I had to change Firefox’s privacy settings to get this experiment to work), and as of today Chrome doesn’t (presumably because Chrome is owned by an ad company).
|
||||
|
||||
### sites have lots of tracking pixels
|
||||
|
||||
Like I expected, sites have **lots** of tracking pixels. For example, wrangler.com loaded 19 different tracking pixels in my browser from a bunch of different domains. The tracking pixels on wrangler.com came from: `ct.pinterest.com`, `af.monetate.net`, `csm.va.us.criteo.net`, `google-analytics.com`, `dpm.demdex.net`, `google.ca`, `a.tribalfusion.com`, `data.photorank.me`, `stats.g.doubleclick.net`, `vfcorp.dl.sc.omtrdc.net`, `ib.adnxs.com`, `idsync.rlcdn.com`, `p.brsrvr.com`, and `adservice.google.com`.
|
||||
|
||||
For most of these trackers, Firefox helpfully pointed out that it would have blocked them if I was using the standard Firefox privacy settings:
|
||||
|
||||
![][8]
|
||||
|
||||
### why browsers matter
|
||||
|
||||
The reason browsers matter so much is that your browser has the final word on what information it sends about you to which websites. The Javascript on the Old Navy’s website can ask your browser to send tracking information about you to Facebook, but your browser doesn’t have to do it! It can decide “oh yeah, I know that facebook.com/tr/ is a tracking pixel, I don’t want my users to be tracked, I’m just not going to send that request”.
|
||||
|
||||
And it can make that behaviour configurable by changing browser settings or installing browser extensions, which is why there are lots of privacy extensions.
|
||||
|
||||
### it’s fun to see how this works!
|
||||
|
||||
I think it’s fun to see how cookies / tracking pixels are used to track you in practice, even if it’s kinda creepy! I sort of knew how this worked before but I’d never actually looked at the cookies on a tracking pixel myself or what kind of information it was sending in its query parameters exactly.
|
||||
|
||||
And if you know how it works, it’s a easier to figure out how to be tracked less!
|
||||
|
||||
### what can you do?
|
||||
|
||||
I do a few small things to get tracked on the internet a little less:
|
||||
|
||||
* install an adblocker (like ublock origin or something), which will block a lot of tracker domains
|
||||
* use Firefox/Safari instead of Chrome (which have stronger default privacy settings right now)
|
||||
* use the [Facebook Container][9] Firefox extension, which takes extra steps to specifically prevent Facebook from tracking you
|
||||
|
||||
|
||||
|
||||
There are still lots of other ways to be tracked on the internet (especially when using mobile apps where you don’t have the same kind of control as with your browser), but I like understanding how this one method of tracking works and think it’s nice to be tracked a little bit less.
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://jvns.ca/blog/how-tracking-pixels-work/
|
||||
|
||||
作者：[Julia Evans][a]
|
||||
选题：[lujun9972][b]
|
||||
译者：[译者ID](https://github.com/译者ID)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]: https://jvns.ca/
|
||||
[b]: https://github.com/lujun9972
|
||||
[1]: https://jvns.ca/images/trackers.png
|
||||
[2]: https://jvns.ca/images/firefox-insecure-settings.png
|
||||
[3]: https://oldnavy.gap.com/browse/product.do?pid=504753002&cid=1125694&pcid=1135640&vid=1&grid=pds_0_109_1
|
||||
[4]: https://developers.facebook.com/docs/facebook-pixel/implementation/
|
||||
[5]: https://jvns.ca/images/fb-old-navy.png
|
||||
[6]: https://oldnavy.gap.com/browse/product.do?pid=504753002&cid=1125694&pcid=1135640&vid=1&grid=pds_0_109_1#pdp-page-content
|
||||
[7]: https://oldnavy.gap.com/browse/category.do?cid=1135640&mlink=5155,m_mts_a
|
||||
[8]: https://jvns.ca/images/firefox-helpful.png
|
||||
[9]: https://addons.mozilla.org/en-CA/firefox/addon/facebook-container/
|
||||
236
sources/tech/20191219 Creating a Bash script template.md
Normal file
236
sources/tech/20191219 Creating a Bash script template.md
Normal file
@@ -0,0 +1,236 @@
|
||||
[#]: collector: (lujun9972)
|
||||
[#]: translator: ( )
|
||||
[#]: reviewer: ( )
|
||||
[#]: publisher: ( )
|
||||
[#]: url: ( )
|
||||
[#]: subject: (Creating a Bash script template)
|
||||
[#]: via: (https://opensource.com/article/19/12/bash-script-template)
|
||||
[#]: author: (David Both https://opensource.com/users/dboth)
|
||||
|
||||
Creating a Bash script template
|
||||
======
|
||||
In the second article in this series, create a fairly simple template
|
||||
that you can use as a starting point for other Bash programs, then test
|
||||
it.
|
||||
![A person programming][1]
|
||||
|
||||
In the [first article][2] in this series, you created a very small, one-line Bash script and explored the reasons for creating shell scripts and why they are the most efficient option for the system administrator, rather than compiled programs.
|
||||
|
||||
In this second article, you will begin creating a Bash script template that can be used as a starting point for other Bash scripts. The template will ultimately contain a Help facility, a licensing statement, a number of simple functions, and some logic to deal with those options and others that might be needed for the scripts that will be based on this template.
|
||||
|
||||
### Why create a template?
|
||||
|
||||
Like automation in general, the idea behind creating a template is to be the "[lazy sysadmin][3]." A template contains the basic components that you want in all of your scripts. It saves time compared to adding those components to every new script and makes it easy to start a new script.
|
||||
|
||||
Although it can be tempting to just throw a few command-line Bash statements together into a file and make it executable, that can be counterproductive in the long run. A well-written and well-commented Bash program with a Help facility and the capability to accept command-line options provides a good starting point for sysadmins who maintain the program, which includes the programs that _you_ write and maintain.
|
||||
|
||||
### The requirements
|
||||
|
||||
You should always create a set of requirements for every project you do. This includes scripts, even if it is a simple list with only two or three items on it. I have been involved in many projects that either failed completely or failed to meet the customer's needs, usually due to the lack of a requirements statement or a poorly written one.
|
||||
|
||||
The requirements for this Bash template are pretty simple:
|
||||
|
||||
1. Create a template that can be used as the starting point for future Bash programming projects.
|
||||
2. The template should follow standard Bash programming practices.
|
||||
3. It must include:
|
||||
* A heading section that can be used to describe the function of the program and a changelog
|
||||
* A licensing statement
|
||||
* A section for functions
|
||||
* A Help function
|
||||
* A function to test whether the program user is root
|
||||
* A method for evaluating command-line options
|
||||
|
||||
|
||||
|
||||
### The basic structure
|
||||
|
||||
A basic Bash script has three sections. Bash has no way to delineate sections, but the boundaries between the sections are implicit.
|
||||
|
||||
* All scripts must begin with the shebang (**#!**), and this must be the first line in any Bash program.
|
||||
* The functions section must begin after the shebang and before the body of the program. As part of my need to document everything, I place a comment before each function with a short description of what it is intended to do. I also include comments inside the functions to elaborate further. Short, simple programs may not need functions.
|
||||
* The main part of the program comes after the function section. This can be a single Bash statement or thousands of lines of code. One of my programs has a little over 200 lines of code, not counting comments. That same program has more than 600 comment lines.
|
||||
|
||||
|
||||
|
||||
That is all there is—just three sections in the structure of any Bash program.
|
||||
|
||||
### Leading comments
|
||||
|
||||
I always add more than this for various reasons. First, I add a couple of sections of comments immediately after the shebang. These comment sections are optional, but I find them very helpful.
|
||||
|
||||
The first comment section is the program name and description and a change history. I learned this format while working at IBM, and it provides a method of documenting the long-term development of the program and any fixes applied to it. This is an important start in documenting your program.
|
||||
|
||||
The second comment section is a copyright and license statement. I use GPLv2, and this seems to be a standard statement for programs licensed under GPLv2. If you use a different open source license, that is fine, but I suggest adding an explicit statement to the code to eliminate any possible confusion about licensing. Scott Peterson's article [_The source code is the license_][4] helps explain the reasoning behind this.
|
||||
|
||||
So now the script looks like this:
|
||||
|
||||
|
||||
```
|
||||
#!/bin/bash
|
||||
################################################################################
|
||||
# scriptTemplate #
|
||||
# #
|
||||
# Use this template as the beginning of a new program. Place a short #
|
||||
# description of the script here. #
|
||||
# #
|
||||
# Change History #
|
||||
# 11/11/2019 David Both Original code. This is a template for creating #
|
||||
# new Bash shell scripts. #
|
||||
# Add new history entries as needed. #
|
||||
# #
|
||||
# #
|
||||
################################################################################
|
||||
################################################################################
|
||||
################################################################################
|
||||
# #
|
||||
# Copyright (C) 2007, 2019 David Both #
|
||||
# [LinuxGeek46@both.org][5] #
|
||||
# #
|
||||
# This program is free software; you can redistribute it and/or modify #
|
||||
# it under the terms of the GNU General Public License as published by #
|
||||
# the Free Software Foundation; either version 2 of the License, or #
|
||||
# (at your option) any later version. #
|
||||
# #
|
||||
# This program is distributed in the hope that it will be useful, #
|
||||
# but WITHOUT ANY WARRANTY; without even the implied warranty of #
|
||||
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the #
|
||||
# GNU General Public License for more details. #
|
||||
# #
|
||||
# You should have received a copy of the GNU General Public License #
|
||||
# along with this program; if not, write to the Free Software #
|
||||
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA #
|
||||
# #
|
||||
################################################################################
|
||||
################################################################################
|
||||
################################################################################
|
||||
|
||||
echo "hello world!"
|
||||
```
|
||||
|
||||
Run the revised program to verify that it still works as expected.
|
||||
|
||||
### About testing
|
||||
|
||||
Now is a good time to talk about testing.
|
||||
|
||||
> "_There is always one more bug."_
|
||||
> — Lubarsky's Law of Cybernetic Entomology
|
||||
|
||||
Lubarsky—whoever that might be—is correct. You can never find all the bugs in your code. For every bug I find, there always seems to be another that crops up, usually at a very inopportune time.
|
||||
|
||||
Testing is not just about programs. It is also about verification that problems—whether caused by hardware, software, or the seemingly endless ways users can find to break things—that are supposed to be resolved actually are. Just as important, testing is also about ensuring that the code is easy to use and the interface makes sense to the user.
|
||||
|
||||
Following a well-defined process when writing and testing shell scripts can contribute to consistent and high-quality results. My process is simple:
|
||||
|
||||
1. Create a simple test plan.
|
||||
2. Start testing right at the beginning of development.
|
||||
3. Perform a final test when the code is complete.
|
||||
4. Move to production and test more.
|
||||
|
||||
|
||||
|
||||
#### The test plan
|
||||
|
||||
There are lots of different formats for test plans. I have worked with the full range—from having it all in my head; to a few notes jotted down on a sheet of paper; and all the way to a complex set of forms that require a full description of each test, which functional code it would test, what the test would accomplish, and what the inputs and results should be.
|
||||
|
||||
Speaking as a sysadmin who has been (but is not now) a tester, I try to take the middle ground. Having at least a short written test plan will ensure consistency from one test run to the next. How much detail you need depends upon how formal your development and test functions are.
|
||||
|
||||
The sample test plan documents I found using Google were complex and intended for large organizations with very formal development and test processes. Although those test plans would be good for people with "test" in their job title, they do not apply well to sysadmins' more chaotic and time-dependent working conditions. As in most other aspects of the job, sysadmins need to be creative. So here is a short list of things to consider including in your test plan. Modify it to suit your needs:
|
||||
|
||||
* The name and a short description of the software being tested
|
||||
* A description of the software features to be tested
|
||||
* The starting conditions for each test
|
||||
* The functions to follow for each test
|
||||
* A description of the desired outcome for each test
|
||||
* Specific tests designed to test for negative outcomes
|
||||
* Tests for how the program handles unexpected inputs
|
||||
* A clear description of what constitutes pass or fail for each test
|
||||
* Fuzzy testing, which is described below
|
||||
|
||||
|
||||
|
||||
This list should give you some ideas for creating your test plans. Most sysadmins should keep it simple and fairly informal.
|
||||
|
||||
#### Test early—test often
|
||||
|
||||
I always start testing my shell scripts as soon as I complete the first portion that is executable. This is true whether I am writing a short command-line program or a script that is an executable file.
|
||||
|
||||
I usually start creating new programs with the shell script template. I write the code for the Help function and test it. This is usually a trivial part of the process, but it helps me get started and ensures that things in the template are working properly at the outset. At this point, it is easy to fix problems with the template portions of the script or to modify it to meet needs that the standard template does not.
|
||||
|
||||
Once the template and Help function are working, I move on to creating the body of the program by adding comments to document the programming steps required to meet the program specifications. Now I start adding code to meet the requirements stated in each comment. This code will probably require adding variables that are initialized in that section of the template—which is now becoming a shell script.
|
||||
|
||||
This is where testing is more than just entering data and verifying the results. It takes a bit of extra work. Sometimes I add a command that simply prints the intermediate result of the code I just wrote and verify that. For more complex scripts, I add a **-t** option for "test mode." In this case, the internal test code executes only when the **-t** option is entered on the command line.
|
||||
|
||||
#### Final testing
|
||||
|
||||
After the code is complete, I go back to do a complete test of all the features and functions using known inputs to produce specific outputs. I also test some random inputs to see if the program can handle unexpected input.
|
||||
|
||||
Final testing is intended to verify that the program is functioning essentially as intended. A large part of the final test is to ensure that functions that worked earlier in the development cycle have not been broken by code that was added or changed later in the cycle.
|
||||
|
||||
If you have been testing the script as you add new code to it, you may think there should not be any surprises during the final test. Wrong! There are always surprises during final testing. Always. Expect those surprises, and be ready to spend time fixing them. If there were never any bugs discovered during final testing, there would be no point in doing a final test, would there?
|
||||
|
||||
#### Testing in production
|
||||
|
||||
Huh—what?
|
||||
|
||||
> "Not until a program has been in production for at least six months will the most harmful error be discovered."
|
||||
> — Troutman's Programming Postulates
|
||||
|
||||
Yes, testing in production is now considered normal and desirable. Having been a tester myself, this seems reasonable. "But wait! That's dangerous," you say. My experience is that it is no more dangerous than extensive and rigorous testing in a dedicated test environment. In some cases, there is no choice because there is no test environment—only production.
|
||||
|
||||
Sysadmins are no strangers to the need to test new or revised scripts in production. Anytime a script is moved into production, that becomes the ultimate test. The production environment constitutes the most critical part of that test. Nothing that testers can dream up in a test environment can fully replicate the true production environment.
|
||||
|
||||
The allegedly new practice of testing in production is just the recognition of what sysadmins have known all along. The best test is production—so long as it is not the only test.
|
||||
|
||||
#### Fuzzy testing
|
||||
|
||||
This is another of those buzzwords that initially caused me to roll my eyes. Its essential meaning is simple: have someone bang on the keys until something happens, and see how well the program handles it. But there really is more to it than that.
|
||||
|
||||
Fuzzy testing is a bit like the time my son broke the code for a game in less than a minute with random input. That pretty much ended my attempts to write games for him.
|
||||
|
||||
Most test plans utilize very specific input that generates a specific result or output. Regardless of whether the test defines a positive or negative outcome as a success, it is still controlled, and the inputs and results are specified and expected, such as a specific error message for a specific failure mode.
|
||||
|
||||
Fuzzy testing is about dealing with randomness in all aspects of the test, such as starting conditions, very random and unexpected input, random combinations of options selected, low memory, high levels of CPU contending with other programs, multiple instances of the program under test, and any other random conditions that you can think of to apply to the tests.
|
||||
|
||||
I try to do some fuzzy testing from the beginning. If the Bash script cannot deal with significant randomness in its very early stages, then it is unlikely to get better as you add more code. This is a good time to catch these problems and fix them while the code is relatively simple. A bit of fuzzy testing at each stage is also useful in locating problems before they get masked by even more code.
|
||||
|
||||
After the code is completed, I like to do some more extensive fuzzy testing. Always do some fuzzy testing. I have certainly been surprised by some of the results. It is easy to test for the expected things, but users do not usually do the expected things with a script.
|
||||
|
||||
### Previews of coming attractions
|
||||
|
||||
This article accomplished a little in the way of creating a template, but it mostly talked about testing. This is because testing is a critical part of creating any kind of program. In the next article in this series, you will add a basic Help function along with some code to detect and act on options, such as **-h**, to your Bash script template.
|
||||
|
||||
### Resources
|
||||
|
||||
* [How to program with Bash: Syntax and tools][6]
|
||||
* [How to program with Bash: Logical operators and shell expansions][7]
|
||||
* [How to program with Bash: Loops][8]
|
||||
|
||||
|
||||
|
||||
* * *
|
||||
|
||||
_This series of articles is partially based on Volume 2, Chapter 10 of David Both's three-part Linux self-study course, [Using and Administering Linux—Zero to SysAdmin][9]._
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://opensource.com/article/19/12/bash-script-template
|
||||
|
||||
作者：[David Both][a]
|
||||
选题：[lujun9972][b]
|
||||
译者：[译者ID](https://github.com/译者ID)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]: https://opensource.com/users/dboth
|
||||
[b]: https://github.com/lujun9972
|
||||
[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/computer_keyboard_laptop_development_code_woman.png?itok=vbYz6jjb (A person programming)
|
||||
[2]: https://opensource.com/article/19/12/introduction-automation-bash-scripts
|
||||
[3]: https://opensource.com/article/18/7/how-be-lazy-sysadmin
|
||||
[4]: https://opensource.com/article/17/12/source-code-license
|
||||
[5]: mailto:LinuxGeek46@both.org
|
||||
[6]: https://opensource.com/article/19/10/programming-bash-syntax-tools
|
||||
[7]: https://opensource.com/article/19/10/programming-bash-logical-operators-shell-expansions
|
||||
[8]: https://opensource.com/article/19/10/programming-bash-loops
|
||||
[9]: http://www.both.org/?page_id=1183
|
||||
192
sources/tech/20191219 Kubernetes namespaces for beginners.md
Normal file
192
sources/tech/20191219 Kubernetes namespaces for beginners.md
Normal file
@@ -0,0 +1,192 @@
|
||||
[#]: collector: (lujun9972)
|
||||
[#]: translator: ( )
|
||||
[#]: reviewer: ( )
|
||||
[#]: publisher: ( )
|
||||
[#]: url: ( )
|
||||
[#]: subject: (Kubernetes namespaces for beginners)
|
||||
[#]: via: (https://opensource.com/article/19/12/kubernetes-namespaces)
|
||||
[#]: author: (Jessica Cherry https://opensource.com/users/jrepka)
|
||||
|
||||
Kubernetes namespaces for beginners
|
||||
======
|
||||
What is a namespace and why do you need it?
|
||||
![Ship captain sailing the Kubernetes seas][1]
|
||||
|
||||
What is in a Kubernetes namespace? As Shakespeare once wrote, which we call a namespace, by any other name, would still be a virtual cluster. By virtual cluster, I mean Kubernetes can offer multiple Kubernetes clusters on a single cluster, much like a virtual machine is an abstraction of its host. According to the [Kubernetes docs][2]:
|
||||
|
||||
> Kubernetes supports multiple virtual clusters backed by the same physical cluster. These virtual clusters are called namespaces.
|
||||
|
||||
Why do you need to use namespaces? In one word: isolation.
|
||||
|
||||
Isolation has many advantages, including that it supports secure and clean environments. If you are the owner of the infrastructure and are supporting developers, isolation is fairly important. The last thing you need is someone who is unfamiliar with how your cluster is built going and changing the system configuration—and possibly disabling everyone's ability to log in.
|
||||
|
||||
### The namespaces that start it all
|
||||
|
||||
The first three namespaces created in a cluster are always **default**, **kube-system**, and **kube-public**. While you can technically deploy within these namespaces, I recommend leaving these for system configuration and not for your projects.
|
||||
|
||||
* **Default** is for deployments that are not given a namespace, which is a quick way to create a mess that will be hard to clean up if you do too many deployments without the proper information. I leave this alone because it serves that one purpose and has confused me on more than one occasion.
|
||||
* **Kube-system** is for all things relating to, you guessed it, the Kubernetes system. Any deployments to this namespace are playing a dangerous game and can accidentally cause irreparable damage to the system itself. Yes, I have done it; I do not recommend it.
|
||||
* **Kube-public** is readable by everyone, but the namespace is reserved for system usage.
|
||||
|
||||
|
||||
|
||||
### Using namespaces for isolation
|
||||
|
||||
I have used namespaces for isolation in a couple of ways. I use them most often to split many users' projects into separate environments. This is useful in preventing cross-project contamination since namespaces provide independent environments. Users can install multiple versions of Jenkins, for example, and their environmental variables won't collide if they are in different namespaces.
|
||||
|
||||
This separation also helps with cleanup. If development groups are working on various projects that suddenly become obsolete, you can delete the namespace and remove everything in one swift movement with **kubectl delete ns <$NAMESPACENAME>**. (Please make sure it's the right namespace. I deleted the wrong one in production once, and it's not pretty.)
|
||||
|
||||
Be aware that this can cause damage across teams and problems for you if you are the infrastructure owner. For example, if you create a namespace with some special, extra-secure DNS functions and the wrong person deletes it, all of your pods and their running applications will be removed with the namespace. Any use of **delete** should be reviewed by a peer (through [GitOps][3]) before hitting the cluster.
|
||||
|
||||
While the official documentation suggests not using multiple namespaces [with 10 or fewer users][2], I still use them in my own cluster for architectural purposes. The cleaner the cluster, the better.
|
||||
|
||||
### What admins need to know about namespaces
|
||||
|
||||
For starters, namespaces cannot be nested in other namespaces. There can be only one namespace with deployments in it. You don't have to use namespaces for versioned projects, but you can always use the labels to separate versioned apps with the same name. Namespaces divide resources between users using resource quotas; for example, _this namespace can only have x_ _number_ _of nodes_. Finally, all namespaces scope down to a unique name for the resource type.
|
||||
|
||||
### Namespace commands in action
|
||||
|
||||
To try out the following namespace commands, you need to have [Minikube][4], [Helm][5], and the [kubectl][6] command line installed. For information about installing them, see my article [_Security scanning your DevOps pipeline_][7] or each project's homepage. I am using the most recent release of Minikube. The manual installation is fast and has consistently worked correctly the first time.
|
||||
|
||||
To get your first set of namespaces:
|
||||
|
||||
|
||||
```
|
||||
jess@Athena:~$ kubectl get namespace
|
||||
NAME STATUS AGE
|
||||
default Active 5m23s
|
||||
kube-public Active 5m24s
|
||||
kube-system Active 5m24s
|
||||
```
|
||||
|
||||
To create a namespace:
|
||||
|
||||
|
||||
```
|
||||
jess@Athena:~$ kubectl create namespace athena
|
||||
namespace/athena created
|
||||
```
|
||||
|
||||
Now developers can deploy to the namespace you created; for example, here's a small and easy Helm chart:
|
||||
|
||||
|
||||
```
|
||||
jess@Athena:~$ helm install teset-deploy stable/redis --namespace athena
|
||||
NAME: teset-deploy
|
||||
LAST DEPLOYED: Sat Nov 23 13:47:43 2019
|
||||
NAMESPACE: athena
|
||||
STATUS: deployed
|
||||
REVISION: 1
|
||||
TEST SUITE: None
|
||||
NOTES:
|
||||
** Please be patient while the chart is being deployed **
|
||||
Redis can be accessed via port 6379 on the following DNS names from within your cluster:
|
||||
|
||||
teset-deploy-redis-master.athena.svc.cluster.local for read/write operations
|
||||
teset-deploy-redis-slave.athena.svc.cluster.local for read-only operations
|
||||
```
|
||||
|
||||
To get your password:
|
||||
|
||||
|
||||
```
|
||||
`export REDIS_PASSWORD=$(kubectl get secret --namespace athena teset-deploy-redis -o jsonpath="{.data.redis-password}" | base64 --decode)`
|
||||
```
|
||||
|
||||
To connect to your Redis server:
|
||||
|
||||
1. Run a Redis pod that you can use as a client: [code] kubectl run --namespace athena teset-deploy-redis-client --rm --tty -i --restart='Never' \
|
||||
--env REDIS_PASSWORD=$REDIS_PASSWORD \
|
||||
\--image docker.io/bitnami/redis:5.0.7-debian-9-r0 -- bash
|
||||
```
|
||||
2. Connect using the Redis CLI: [code] redis-cli -h teset-deploy-redis-master -a $REDIS_PASSWORD
|
||||
redis-cli -h teset-deploy-redis-slave -a $REDIS_PASSWORD
|
||||
```
|
||||
|
||||
|
||||
|
||||
To connect to your database from outside the cluster:
|
||||
|
||||
|
||||
```
|
||||
kubectl port-forward --namespace athena svc/teset-deploy-redis-master 6379:6379 &
|
||||
redis-cli -h 127.0.0.1 -p 6379 -a $REDIS_PASSWORD
|
||||
```
|
||||
|
||||
Now that this deployment is out, you have a chart deployed in your namespace named **test-deploy**.
|
||||
|
||||
To look at what pods are in your namespace:
|
||||
|
||||
|
||||
```
|
||||
jess@Athena:~$ kubectl get pods --namespace athena
|
||||
NAME READY STATUS RESTARTS AGE
|
||||
teset-deploy-redis-master-0 1/1 Running 0 2m38s
|
||||
teset-deploy-redis-slave-0 1/1 Running 0 2m38s
|
||||
teset-deploy-redis-slave-1 1/1 Running 0 90s
|
||||
```
|
||||
|
||||
At this point, you have officially isolated your application to a single namespace and created one virtual cluster that talks internally only to itself.
|
||||
|
||||
Delete everything with a single command:
|
||||
|
||||
|
||||
```
|
||||
jess@Athena:~$ kubectl delete namespace athena
|
||||
namespace "athena" deleted
|
||||
```
|
||||
|
||||
Because this deletes the application's entire internal configuration, the delete may take some time, depending on how large your deployment is.
|
||||
|
||||
Double-check that everything has been removed:
|
||||
|
||||
|
||||
```
|
||||
jess@Athena:~$ kubectl get pods --all-namespaces
|
||||
NAMESPACE NAME READY STATUS RESTARTS AGE
|
||||
kube-system coredns-5644d7b6d9-4vxv6 1/1 Running 0 32m
|
||||
kube-system coredns-5644d7b6d9-t5wn7 1/1 Running 0 32m
|
||||
kube-system etcd-minikube 1/1 Running 0 31m
|
||||
kube-system kube-addon-manager-minikube 1/1 Running 0 32m
|
||||
kube-system kube-apiserver-minikube 1/1 Running 0 31m
|
||||
kube-system kube-controller-manager-minikube 1/1 Running 0 31m
|
||||
kube-system kube-proxy-5tdmh 1/1 Running 0 32m
|
||||
kube-system kube-scheduler-minikube 1/1 Running 0 31m
|
||||
kube-system storage-provisioner 1/1 Running 0 27m
|
||||
```
|
||||
|
||||
This is a list of all the pods and all the known namespaces where they live. As you can see, the application and namespace you previously made are now gone.
|
||||
|
||||
### Namespaces in practice
|
||||
|
||||
I currently use namespaces for security purposes, including reducing the privileges of users with limitations. You can limit everything—from which roles can access a namespace to their quota levels for cluster resources, like CPUs. For example, I use resource quotas and role-based access control (RBAC) configurations to confirm that a namespace is accessible only by the appropriate service accounts.
|
||||
|
||||
On the isolation side of security, I don't want my home Jenkins application to be accessible over a trusted local network as secure images that have public IP addresses (and thus, I have to assume, could be compromised).
|
||||
|
||||
Namespaces can also be helpful for budgeting purposes if you have a hard budget on how much you can use in your cloud platform for nodes (or, in my case, how much I can deploy before [segfaulting][8] my home server). Although this is out of scope for this article, and it's complicated, it is worth researching and taking advantage of to prevent overextending your cluster.
|
||||
|
||||
### Conclusion
|
||||
|
||||
Namespaces are a great way to isolate projects and applications. This is just a quick introduction to the topic, so I encourage you to do more advanced research on namespaces and use them more in your work.
|
||||
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
via: https://opensource.com/article/19/12/kubernetes-namespaces
|
||||
|
||||
作者：[Jessica Cherry][a]
|
||||
选题：[lujun9972][b]
|
||||
译者：[译者ID](https://github.com/译者ID)
|
||||
校对：[校对者ID](https://github.com/校对者ID)
|
||||
|
||||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||||
|
||||
[a]: https://opensource.com/users/jrepka
|
||||
[b]: https://github.com/lujun9972
|
||||
[1]: https://opensource.com/sites/default/files/styles/image-full-size/public/lead-images/ship_captain_devops_kubernetes_steer.png?itok=LAHfIpek (Ship captain sailing the Kubernetes seas)
|
||||
[2]: https://kubernetes.io/docs/concepts/overview/working-with-objects/namespaces/
|
||||
[3]: https://www.weave.works/blog/gitops-operations-by-pull-request
|
||||
[4]: https://kubernetes.io/docs/tasks/tools/install-minikube/
|
||||
[5]: https://helm.sh/
|
||||
[6]: https://kubernetes.io/docs/tasks/tools/install-kubectl/
|
||||
[7]: https://opensource.com/article/19/7/security-scanning-your-devops-pipeline
|
||||
[8]: https://en.wikipedia.org/wiki/Segmentation_fault
|
||||
Reference in New Issue
Block a user