Add `federation.hostmeta` generators for Matrix client and server well-known files.

Django views and url configuration also included for convenience.

CHANGELOG.md

@@ -2,6 +2,11 @@
 
 ## [unreleased]
 
+### Added
+
+* Add `federation.hostmeta` generators for Matrix client and server well-known files. 
+  Django views and url configuration also included for convenience.
+
 ## [0.21.0] - 2020-12-20
 
 ### Added

docs/usage.rst

@@ -149,6 +149,8 @@ Generator classes
 .. autoclass:: federation.hostmeta.generators.DiasporaHostMeta
 .. autoclass:: federation.hostmeta.generators.DiasporaWebFinger
 .. autoclass:: federation.hostmeta.generators.DiasporaHCard
+.. autoclass:: federation.hostmeta.generators.MatrixClientWellKnown
+.. autoclass:: federation.hostmeta.generators.MatrixServerWellKnown
 .. autoclass:: federation.hostmeta.generators.NodeInfo
 .. autoclass:: federation.hostmeta.generators.RFC7033Webfinger
 .. autoclass:: federation.hostmeta.generators.SocialRelayWellKnown
@@ -189,6 +191,8 @@ It must be installed separately.
 
 .. autofunction:: federation.entities.activitypub.django.views.activitypub_object_view
 .. autofunction:: federation.hostmeta.django.generators.rfc7033_webfinger_view
+.. autofunction:: federation.hostmeta.django.generators.matrix_client_wellknown_view
+.. autofunction:: federation.hostmeta.django.generators.matrix_server_wellknown_view
 .. autofunction:: federation.hostmeta.django.generators.nodeinfo2_view
 
 Configuration
@@ -209,6 +213,7 @@ Some settings need to be set in Django settings. An example is below:
         "get_object_function": "myproject.utils.get_object",
         "get_private_key_function": "myproject.utils.get_private_key",
         "get_profile_function": "myproject.utils.get_profile",
+        "matrix_config_function": "myproject.utils.matrix_config_funct",
         "nodeinfo2_function": "myproject.utils.get_nodeinfo2_data",
         "process_payload_function": "myproject.utils.process_payload",
         "search_path": "/search/?q=",
@@ -219,6 +224,23 @@ Some settings need to be set in Django settings. An example is below:
 * ``get_object_function`` should be the full path to a function that will return the object matching the ActivityPub ID for the request object passed to this function.
 * ``get_private_key_function`` should be the full path to a function that will accept a federation ID (url, handle or guid) and return the private key of the user (as an RSA object). Required for example to sign outbound messages in some cases.
 * ``get_profile_function`` should be the full path to a function that should return a ``Profile`` entity. The function should take one or more keyword arguments: ``fid``, ``handle``, ``guid`` or ``request``. It should look up a profile with one or more of the provided parameters.
+* ``matrix_config_function`` (optional) function that returns a Matrix configuration dictionary, with the following objects:
+
+::
+
+    {
+      # Location of the homeserver (not server name)
+      "homeserver_base_url": "https://matrix.domain.tld",
+      # Homeserver domain and port (not server domain)
+      "homeserver_domain_with_port": "matrix.domain.tld:443",
+      # (Optional) location of identity server
+      "identity_server_base_url": "https://id.domain.tld",
+      # (Optional) other keys to include in the client well-known (must be a dictionary)
+      "client_wellknown_other_keys": {
+        "org.foo.key" "barfoo",
+      },
+    }
+
 * ``nodeinfo2_function`` (optional) function that returns data for generating a `NodeInfo2 document <https://github.com/jaywink/nodeinfo2>`_. Once configured the path ``/.well-known/x-nodeinfo2`` will automatically generate a NodeInfo2 document. The function should return a ``dict`` corresponding to the NodeInfo2 schema, with the following minimum items:
 
 ::

federation/hostmeta/django/generators.py

@@ -1,8 +1,11 @@
 import logging
 
+# noinspection PyPackageRequirements
 from django.http import HttpResponseBadRequest, JsonResponse, HttpResponseNotFound
 
-from federation.hostmeta.generators import RFC7033Webfinger, generate_nodeinfo2_document
+from federation.hostmeta.generators import (
+    RFC7033Webfinger, generate_nodeinfo2_document, MatrixClientWellKnown, MatrixServerWellKnown,
+)
 from federation.utils.django import get_configuration, get_function_from_config
 from federation.utils.text import get_path_from_url
 
@@ -19,6 +22,34 @@ def nodeinfo2_view(request, *args, **kwargs):
     return JsonResponse(generate_nodeinfo2_document(**nodeinfo2))
 
 
+def matrix_client_wellknown_view(request, *args, **kwargs):
+    try:
+        matrix_config_func = get_function_from_config("matrix_config_function")
+    except AttributeError:
+        return HttpResponseBadRequest("Not configured")
+    matrix_config = matrix_config_func()
+
+    wellknown = MatrixClientWellKnown(
+        homeserver_base_url=matrix_config["homeserver_base_url"],
+        identity_server_base_url=matrix_config.get("identity_server_base_url"),
+        other_keys=matrix_config.get("client_wellknown_other_keys"),
+    )
+    return JsonResponse(wellknown.render())
+
+
+def matrix_server_wellknown_view(request, *args, **kwargs):
+    try:
+        matrix_config_func = get_function_from_config("matrix_config_function")
+    except AttributeError:
+        return HttpResponseBadRequest("Not configured")
+    matrix_config = matrix_config_func()
+
+    wellknown = MatrixServerWellKnown(
+        homeserver_domain_with_port=matrix_config["homeserver_domain_with_port"],
+    )
+    return JsonResponse(wellknown.render())
+
+
 def rfc7033_webfinger_view(request, *args, **kwargs):
     """
     Django view to generate an RFC7033 webfinger.

federation/hostmeta/django/urls.py

@@ -1,9 +1,14 @@
+# noinspection PyPackageRequirements
 from django.conf.urls import url
 
 from federation.hostmeta.django import rfc7033_webfinger_view
-from federation.hostmeta.django.generators import nodeinfo2_view
+from federation.hostmeta.django.generators import (
+    nodeinfo2_view, matrix_client_wellknown_view, matrix_server_wellknown_view,
+)
 
 urlpatterns = [
+    url(r'^.well-known/matrix/client$', matrix_client_wellknown_view, name="matrix-client-wellknown"),
+    url(r'^.well-known/matrix/server$', matrix_server_wellknown_view, name="matrix-server-wellknown"),
     url(r'^.well-known/webfinger$', rfc7033_webfinger_view, name="rfc7033-webfinger"),
     url(r'^.well-known/x-nodeinfo2$', nodeinfo2_view, name="nodeinfo2"),
 ]

federation/hostmeta/generators.py

@@ -3,6 +3,7 @@ import os
 import warnings
 from base64 import b64encode
 from string import Template
+from typing import Dict
 
 from jsonschema import validate
 from jsonschema.exceptions import ValidationError
@@ -331,6 +332,43 @@ def get_nodeinfo_well_known_document(url, document_path=None):
     }
 
 
+class MatrixClientWellKnown:
+    """
+    Matrix Client well-known as per https://matrix.org/docs/spec/client_server/r0.6.1#server-discovery
+    """
+    def __init__(self, homeserver_base_url: str, identity_server_base_url: str = None, other_keys: Dict = None):
+        self.homeserver_base_url = homeserver_base_url
+        self.identity_server_base_url = identity_server_base_url
+        self.other_keys = other_keys
+
+    def render(self):
+        doc = {
+            "m.homeserver": {
+                "base_url": self.homeserver_base_url,
+            }
+        }
+        if self.identity_server_base_url:
+            doc["m.identity_server"] = {
+                "base_url": self.identity_server_base_url,
+            }
+        if self.other_keys:
+            doc.update(self.other_keys)
+        return doc
+
+
+class MatrixServerWellKnown:
+    """
+    Matrix Server well-known as per https://matrix.org/docs/spec/server_server/r0.1.4#server-discovery
+    """
+    def __init__(self, homeserver_domain_with_port: str):
+        self.homeserver_domain_with_port = homeserver_domain_with_port
+
+    def render(self):
+        return {
+            "m.server": self.homeserver_domain_with_port,
+        }
+
+
 class RFC7033Webfinger:
     """
     RFC 7033 webfinger - see https://tools.ietf.org/html/rfc7033