Implement XRD host-meta generator

federation/hostmeta/generators.py

@@ -0,0 +1,46 @@
+from xrd import XRD, Link
+
+
+def generate_host_meta(template=None, *args, **kwargs):
+    """Generate a host-meta XRD document.
+
+    Args:
+        template (str, optional)    - Ready template to fill with args, for example "diaspora".
+        **kwargs                    - Template specific key-value pairs to fill in, see classes.
+
+    Returns:
+        str                         - XRD document
+    """
+    if template == "diaspora":
+        hostmeta = DiasporaHostMeta(*args, **kwargs)
+    else:
+        hostmeta = BaseHostMeta(*args, **kwargs)
+    return hostmeta.render()
+
+
+class BaseHostMeta(object):
+    def __init__(self, *args, **kwargs):
+        self.xrd = XRD()
+
+    def render(self):
+        return self.xrd.to_xml()
+
+
+class DiasporaHostMeta(BaseHostMeta):
+    """Diaspora host-meta.
+
+    NOTE! Diaspora .well-known/host-meta seems to define 'encoding="UTF-8"' from server implementation.
+    The xrd.XRD module does not define this or allow defining it when rendering the XML. This will need to be
+    fixed if that is a problem to Diaspora or other servers.
+
+    Requires keyword args:
+        webfinger_host (str)
+    """
+    def __init__(self, *args, **kwargs):
+        super(DiasporaHostMeta, self).__init__(*args, **kwargs)
+        link = Link(
+            rel='lrdd',
+            type_='application/xrd+xml',
+            template='%s/webfinger?q={uri}' % kwargs["webfinger_host"]
+        )
+        self.xrd.links.append(link)

federation/tests/hostmeta/test_generators.py

@@ -0,0 +1,20 @@
+import pytest
+from federation.hostmeta.generators import generate_host_meta
+
+
+DIASPORA_HOSTMETA = """<?xml version="1.0" ?>
+<XRD xmlns="http://docs.oasis-open.org/ns/xri/xrd-1.0">
+  <Link rel="lrdd" template="https://example.com/webfinger?q={uri}" type="application/xrd+xml"/>
+</XRD>
+"""
+
+
+class TestDiasporaHostMetaGenerator(object):
+
+    def test_generate_valid_host_meta(self):
+        hostmeta = generate_host_meta("diaspora", webfinger_host="https://example.com")
+        assert hostmeta.toprettyxml(indent="  ") == DIASPORA_HOSTMETA
+
+    def test_generate_host_meta_requires_webfinger_host(self):
+        with pytest.raises(KeyError):
+            generate_host_meta("diaspora")

setup.py

@@ -16,6 +16,7 @@ setup(
         "lxml==3.4.4",
         "pycrypto==2.6.1",
         "python-dateutil==2.4.2",
+        "python-xrd==0.1",
     ],
     test_require=[
         "pytest==2.7.2",