mr.scripty 1.0b1

Supported options

The recipe supports the any number of options which are python functions. Since the ini parser used with buildout doesn’t preserve initial whitespace each line of your method should start with a … followed by the whitespace as per normal python. They will look like this

[myscripts]
recipe = mr.scripty
function1 =
  ... x = range(1,10)
  ... return ' '.join(x)

The return value will be stored as a value in the buildout parts options which is available for replacement in other buildout parts. What is returned is always converted to a string.

These functions are actually instance methods of the instance of the scripty recipe. Methods are evaluated during the initialization of the Recipe instance, i.e. after the cfg is read but before any install or ‘update` recipe methods have been called. Method names of install, update are treated specially and not evaluated during initialization but rather during the install and update phases of building this recipe instance. These can be used as quick inplace replacement for creating a real recipe and have the same semantics as detailed in http://pypi.python.org/pypi/zc.buildout#id3. In addition any option beggining with _ is not evaluated so can be used as a private method. Since these are methods self is an available local variable which refers to the recipe instance. self.options, self.buildout and self.name are also available.

Example usage

Let’s say you want to transform the a varnish:backends value to what can be used inside haproxy:

>>> write('buildout.cfg',
... """
... [buildout]
... parts = scripty echobackends echorepeat
...
... [varnish]
... backends =
...         myhost.com:255.255.255.1
...     myhost2.com:125.125.125.1
...
... [scripty]
... recipe = mr.scripty
... backends =
...   ... res = ""
...   ... for line in self.buildout['varnish']['backends'].splitlines():
...   ...    if ':' not in line:
...   ...      continue
...   ...    host,dest = line.split(':')
...   ...    host = host.split('.')[0]
...   ...    res += "acl %s url_sub VirtualHostRoot/%s\\n" % (dest,host)
...   ... return res
... repeat =
...   ... opt_repeatx = int(self.options['repeatx'])
...   ... fun_repeatx = self.repeatx()
...   ... return '\\n'.join(["this is line %s"%i for i in range(1,opt_repeatx+1)])
... repeatx = return '10'
...
... [echobackends]
... recipe = mr.scripty
... install = print self.buildout['scripty']['backends']; return []
...
... [echorepeat]
... recipe = mr.scripty
... install =
...   ... script = self.buildout['scripty']
...   ... print script['repeat']
...   ... return []
... """)

Running the buildout gives us:

>>> print 'start', system(buildout)
start...
Installing echobackends.
acl host url_sub VirtualHostRoot/255.255.255.1
acl host2 url_sub VirtualHostRoot/125.125.125.1
<BLANKLINE>
Installing echorepeat.
this is line 1
this is line 2
this is line 3
this is line 4
this is line 5
this is line 6
this is line 7
this is line 8
this is line 9
this is line 10
<BLANKLINE>

From this example you’ll notice several things. Options that are part of a mr.scripty part are turned into methods of the part instance and can call each other. In addition, each method can be called from other buildout recipes by accessing the option via ${part:method} or in code via self.buildout[part][method].