collective.recipe.zopeinstancemultiplier 0.1.0

概述

本食谱使配置多个Zope实例变得更容易。

示例用法

我们将从创建一个使用本食谱的buildout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
... """)

配置的 instance-multiplier 部分被设置为生成两个额外的部分，使用 instance 部分作为模型。将创建两个新的部分： instance-1 和 instance-2。这些部分将完全复制模型部分，除了 http-address 选项，该选项将针对每个部分递增。因此我们将有

• instance 的 http-address 等于 8080。

• instance-1 的 http-address 等于 8081。

• instance-2 的 http-address 等于 8082。

:printer 食谱仅在安装时打印出部分选项。我们不希望在测试时生成真实的Zope实例。在实际生活中，您将使用 plone.recipe.zope2instance。

运行buildout将给出

>>> 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

在 http-address 选项中支持“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buildout将给出

>>> 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

有时您想在集群中拥有一个自定义实例。为了简化配置，"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。您可以使用此选项如下

>>> 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buildout将给出

>>> 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

根据部分名称（支持 ${:_buildout_section_name}）

有时选项值必须包含部分名称。Buildout通过提供特殊值 _buildout_section_name_ 来支持这种情况。

以下示例展示了在多个Zope实例场景中，如何通常使用此特殊值，而不使用此食谱

[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

尝试将先前示例适配到此食谱的工作方式如下

[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，这会 失败。因为Buildout的工作方式，在食谱可以访问用于乘以其实例部分的实例部分时，变量替换已经发生。

为了使其工作，需要进行简单适配。只需包含一个额外的美元符号以转义变量。以下是一个示例

>>> 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buildout将给出

>>> 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
...

变更日志