Ship the email templates as package_data

move the example email templates into the synapse package so that they can be
used as package data, which should mean that all of the packaging mechanisms
(pip, docker, debian, arch, etc) should now come with the example templates.

In order to grandfather in people who relied on the templates being in the old
place, check for that situation and fall back to using the defaults if the
templates directory does not exist.

MANIFEST.in

@@ -12,12 +12,12 @@ recursive-include synapse/storage/schema *.sql
 recursive-include synapse/storage/schema *.py
 
 recursive-include docs *
-recursive-include res *
 recursive-include scripts *
 recursive-include scripts-dev *
 recursive-include synapse *.pyi
 recursive-include tests *.py
 
+recursive-include synapse/res *
 recursive-include synapse/static *.css
 recursive-include synapse/static *.gif
 recursive-include synapse/static *.html

changelog.d/4052.feature

@@ -0,0 +1,12 @@
+Ship the example email templates as part of the package
+
+**Note**: if you deploy your Synapse instance from a git checkout or a github
+snapshot URL, then this means that the example email templates will no longer
+be installed in `res/templates`. If you have email notifications enabled, you
+should ensure that `email.template_dir` is either configured to point at a
+directory where you have installed customised templates, or leave it unset to
+use the default templates.
+
+The configuration parser will try to detect the situation where
+`email.template_dir` is incorrectly set to `res/templates` and do the right
+thing, but will warn about this.

docker/conf/homeserver.yaml

@@ -211,7 +211,9 @@ email:
    require_transport_security: False
    notif_from: "{{ SYNAPSE_SMTP_FROM or "hostmaster@" + SYNAPSE_SERVER_NAME }}"
    app_name: Matrix
-   template_dir: res/templates
+   # if template_dir is unset, uses the example templates that are part of
+   # the Synapse distribution.
+   #template_dir: res/templates
    notif_template_html: notif_mail.html
    notif_template_text: notif_mail.txt
    notif_for_new_users: True

synapse/config/emailconfig.py

@@ -13,11 +13,19 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+from __future__ import print_function
+
 # This file can't be called email.py because if it is, we cannot:
 import email.utils
+import logging
+import os
+import sys
+import textwrap
 
 from ._base import Config
 
+logger = logging.getLogger(__name__)
+
 
 class EmailConfig(Config):
     def read_config(self, config):
@@ -38,7 +46,6 @@ class EmailConfig(Config):
                 "smtp_host",
                 "smtp_port",
                 "notif_from",
-                "template_dir",
                 "notif_template_html",
                 "notif_template_text",
             ]
@@ -62,9 +69,27 @@ class EmailConfig(Config):
             self.email_smtp_host = email_config["smtp_host"]
             self.email_smtp_port = email_config["smtp_port"]
             self.email_notif_from = email_config["notif_from"]
-            self.email_template_dir = email_config["template_dir"]
             self.email_notif_template_html = email_config["notif_template_html"]
             self.email_notif_template_text = email_config["notif_template_text"]
+
+            self.email_template_dir = email_config.get("template_dir")
+
+            # backwards-compatibility hack
+            if (
+                self.email_template_dir == "res/templates"
+                and not os.path.isfile(
+                    os.path.join(self.email_template_dir, self.email_notif_template_text)
+                )
+            ):
+                t = """\
+WARNING: The email notifier is configured to look for templates in '%s', but no templates
+could be found there. We will fall back to using the example templates; to get rid of this
+warning, leave 'email.template_dir' unset.
+""" % (self.email_template_dir,)
+
+                print(textwrap.fill(t, width=80) + "\n", file=sys.stderr)
+                self.email_template_dir = None
+
             self.email_notif_for_new_users = email_config.get(
                 "notif_for_new_users", True
             )
@@ -113,7 +138,9 @@ class EmailConfig(Config):
         #   require_transport_security: False
         #   notif_from: "Your Friendly %(app)s Home Server <noreply@example.com>"
         #   app_name: Matrix
-        #   template_dir: res/templates
+        #   # if template_dir is unset, uses the example templates that are part of
+        #   # the Synapse distribution.
+        #   #template_dir: res/templates
         #   notif_template_html: notif_mail.html
         #   notif_template_text: notif_mail.txt
         #   notif_for_new_users: True

synapse/push/mailer.py

@@ -528,7 +528,10 @@ def load_jinja2_templates(config):
     """
     logger.info("loading jinja2")
 
-    loader = jinja2.FileSystemLoader(config.email_template_dir)
+    if config.email_template_dir:
+        loader = jinja2.FileSystemLoader(config.email_template_dir)
+    else:
+        loader = jinja2.PackageLoader('synapse', 'res/templates')
     env = jinja2.Environment(loader=loader)
     env.filters["format_ts"] = format_ts_filter
     env.filters["mxc_to_http"] = _create_mxc_to_http_filter(config)