collective.recipe.zopeinstancemultiplier 0.1.0

概述

这个方法使得配置多个zope实例更加容易。

示例用法

我们将从创建使用配方的构建开始：

>>> write('buildout.cfg',
... """
... [buildout]
... parts = instance instance-multiplier
...
... [instance]
... recipe = collective.recipe.zopeinstancemultiplier:printer
... http-address = 8080
... option-foo = value-foo
... option-bar = value-bar
...
... [instance-multiplier]
... recipe = collective.recipe.zopeinstancemultiplier
... instance-part = instance
... count = 2
... """)

instance-multiplier部分配置为生成两个附加部分， 使用instance部分作为模型。将创建两个新部分：instance-1和 instance-2。这些部分将是模型部分的精确克隆，除了 http-address选项，将为每个部分递增。因此，我们将得到：

• instance与http-address等于8080。
• instance-1与http-address等于8081。
• instance-2与http-address等于8082。

:printer配方只在安装时打印出部件选项。我们不想 生成真正的zope实例来测试。在现实生活中你会用到 plone.recipe.zope2instance。

运行构建会给我们带来：

>>> print 'start', system(buildout)
start...
Installing instance.
http-address = 8080
option-bar = value-bar
option-foo = value-foo
Installing instance-1.
http-address = 8081
option-bar = value-bar
option-foo = value-foo
Installing instance-2.
http-address = 8082
option-bar = value-bar
option-foo = value-foo
...

支持“ip:port”语法

还支持http-address选项中的“ip:port”语法：

>>> write('buildout.cfg',
... """
... [buildout]
... parts = my-instance my-instance-multiplier
...
... [my-instance]
... recipe = collective.recipe.zopeinstancemultiplier:printer
... http-address = 127.0.0.1:1234
...
... [my-instance-multiplier]
... recipe = collective.recipe.zopeinstancemultiplier
... instance-part = my-instance
... count = 2
... """)

运行构建会给我们带来：

>>> print 'start', system(buildout)
start...
Installing my-instance.
http-address = 127.0.0.1:1234
Installing my-instance-1.
http-address = 127.0.0.1:1235
Installing my-instance-2.
http-address = 127.0.0.1:1236
...

添加自定义实例

有时您希望在集群中有一个自定义实例。使配置更容易 “乘数”部分提供了一个包含下一个要使用的端口的特殊选项。你可以 像这样使用此选项：

>>> write('buildout.cfg',
... """
... [buildout]
... parts = instance instance-multiplier instance-custom
...
... [instance]
... recipe = collective.recipe.zopeinstancemultiplier:printer
... http-address = 8080
...
... [instance-multiplier]
... recipe = collective.recipe.zopeinstancemultiplier
... instance-part = instance
... count = 2
...
... [instance-custom]
... <= instance
... http-address = ${instance-multiplier:next-http-address}
... custom-option = custom-value
... """)

运行构建会给我们带来：

>>> print 'start', system(buildout)
start ...
Installing instance.
http-address = 8080
Installing instance-1.
http-address = 8081
Installing instance-2.
http-address = 8082
...
Installing instance-custom.
custom-option = custom-value
http-address = 8083

取决于部件的名称（${:_buildout_section_name}support）

有时选项值必须包含零件的名称。buildout通过 提供特殊值_buildout_section_name_。

下面的示例演示了如何在多个zope中使用此特殊值 实例场景，不使用此配方：

[instance]
...
http-address = 8080
special-log-path = /path/to/the/logs/${:_buildout_section_name}.log

[instance-1]
<= instance
http-address = 8081

[instance-2]
<= instance
http-address = 8082

尝试将上一个示例调整为使用此配方，如下所示：

[instance]
...
http-address = 8080
special-log-path = /path/to/the/logs/${:_buildout_section_name}.log

[instance-multiplier]
recipe = collective.recipe.zopeinstancemultiplier
instance-part = instance
count = 2

然而，这将失败。因为buildout的工作方式，在配方可以访问的时候 为了使instance部分相乘，变量替换已经发生。

要使它起作用，需要简单的适应。只需添加一个额外的美元符号，以便 退出变量。下面是一个示例：

>>> write('buildout.cfg',
... """
... [buildout]
... parts = instance instance-multiplier
...
... [instance]
... recipe = collective.recipe.zopeinstancemultiplier:printer
... http-address = 8080
... special-log-path = /path/to/the/logs/$${:_buildout_section_name_}.log
...
... [instance-multiplier]
... recipe = collective.recipe.zopeinstancemultiplier
... instance-part = instance
... count = 2
... """)

运行构建会给我们带来：

>>> print 'start', system(buildout)
start ...
Installing instance.
http-address = 8080
special-log-path = /path/to/the/logs/instance.log
Installing instance-1.
http-address = 8081
special-log-path = /path/to/the/logs/instance-1.log
Installing instance-2.
http-address = 8082
special-log-path = /path/to/the/logs/instance-2.log
...

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