Prove that keys are passed to libnetworkcache.

src/zc/buildout/networkcache.txt

@@ -693,6 +693,97 @@ Of course eggs are also supported by networkcache:
    Uploading http://localhost/demoneeded-1.2c1.zip into network cache.
    Got demoneeded 1.2c1.
 
+It is possible to pass SSL certificates and key to be used by authentication.
+In order to do it NetworkcacheClient.upload method have to be patched to show
+that proper keys are used.
+
+   >>> mkdir(sample_buildout, 'ncpatch')
+   >>> write(sample_buildout, 'ncpatch', 'ncpatch.py',
+   ... """
+   ... def patched(self, *args, **kwargs):
+   ...     print 'shacache_cert_file', self.shacache_cert_file
+   ...     print 'shacache_key_file', self.shacache_key_file
+   ...     print 'shadir_cert_file', self.shadir_cert_file
+   ...     print 'shadir_key_file', self.shadir_key_file
+   ...     return False
+   ...
+   ... def ext(buildout):
+   ...     print 'Patching slapos.libnetworkcache'
+   ...     import slapos.libnetworkcache
+   ...     slapos.libnetworkcache.NetworkcacheClient.upload = patched
+   ... """)
+   >>> write(sample_buildout, 'ncpatch', 'setup.py',
+   ... """
+   ... from setuptools import setup
+   ...
+   ... setup(
+   ...     name = "ncpatch",
+   ...     entry_points = {'zc.buildout.extension': ['ncpatch = ncpatch:ext']},
+   ...     )
+   ... """)
+   >>> write(sample_buildout, 'ncpatch', 'README.txt', " ")
+
+Lets activiate this extension:
+
+    >>> write(sample_buildout, 'buildout.cfg',
+    ... """
+    ... [buildout]
+    ... develop = ncpatch
+    ... parts =
+    ... """)
+   >>> print system(buildout)
+   Develop: '/sample-buildout/ncpatch'
+   Uninstalling eggs.
+
+Lets clean networkcache:
+
+   >>> rmdir(nc_data)
+   >>> mkdir(nc_data)
+
+And see what happens:
+
+   >>> write(sample_buildout, 'buildout.cfg',
+   ... '''
+   ... [buildout]
+   ...
+   ... networkcache-section = networkcache
+   ... find-links = %(link_server)s
+   ... develop = ncpatch download
+   ... extensions = ncpatch
+   ... parts = download
+   ...
+   ... [download]
+   ... recipe = download
+   ... url = %(remote_server_url)shello.txt
+   ...
+   ... [networkcache]
+   ... download-cache-url = %(nc_url)sshacache
+   ... download-dir-url = %(nc_url)sshadir
+   ... upload-cache-url = %(nc_url)sshacache
+   ... upload-dir-url = %(nc_url)sshadir
+   ... shacache-cert-file = /path/to/shacache/cert/file
+   ... shacache-key-file = /path/to/shacache/key/file
+   ... shadir-cert-file = /path/to/shadir/cert/file
+   ... shadir-key-file = /path/to/shadir/key/file
+   ... ''' % globals())
+   >>> print system(buildout)
+   Networkcache enabled.
+   Networkcache download cache: 'http://localhost/shacache', directory 'http://localhost/shadir'
+   Networkcache upload cache: 'http://localhost/shacache', directory 'http://localhost/shadir'
+   Patching slapos.libnetworkcache
+   Develop: '/sample-buildout/ncpatch'
+   Develop: '/sample-buildout/download'
+   Installing download.
+   Downloading http://localhost/hello.txt
+   Downloading hello.txt from network cache.
+   Failed to download from network cache hello.txt:...404...
+   Uploading http://localhost/hello.txt into network cache.
+   shacache_cert_file /path/to/shacache/cert/file
+   shacache_key_file /path/to/shacache/key/file
+   shadir_cert_file /path/to/shadir/cert/file
+   shadir_key_file /path/to/shadir/key/file
+   download: Downloaded http://localhost/hello.txt
+
 Lets clean networkcache:
 
    >>> rmdir(nc_data)