Convert additional templates to Jinja (#8444)

This converts a few more of our inline HTML templates to Jinja. This is somewhat part of #7280 and should make it a bit easier to customize these in the future.

synapse/config/_base.py

@@ -242,12 +242,11 @@ class Config:
         env = jinja2.Environment(loader=loader, autoescape=autoescape)
 
         # Update the environment with our custom filters
-        env.filters.update(
-            {
-                "format_ts": _format_ts_filter,
-                "mxc_to_http": _create_mxc_to_http_filter(self.public_baseurl),
-            }
-        )
+        env.filters.update({"format_ts": _format_ts_filter})
+        if self.public_baseurl:
+            env.filters.update(
+                {"mxc_to_http": _create_mxc_to_http_filter(self.public_baseurl)}
+            )
 
         for filename in filenames:
             # Load the template

synapse/config/captcha.py

@@ -28,6 +28,9 @@ class CaptchaConfig(Config):
             "recaptcha_siteverify_api",
             "https://www.recaptcha.net/recaptcha/api/siteverify",
         )
+        self.recaptcha_template = self.read_templates(
+            ["recaptcha.html"], autoescape=True
+        )[0]
 
     def generate_config_section(self, **kwargs):
         return """\

synapse/config/consent_config.py

@@ -89,6 +89,8 @@ class ConsentConfig(Config):
 
     def read_config(self, config, **kwargs):
         consent_config = config.get("user_consent")
+        self.terms_template = self.read_templates(["terms.html"], autoescape=True)[0]
+
         if consent_config is None:
             return
         self.user_consent_version = str(consent_config["version"])

synapse/config/registration.py

@@ -187,6 +187,11 @@ class RegistrationConfig(Config):
             session_lifetime = self.parse_duration(session_lifetime)
         self.session_lifetime = session_lifetime
 
+        # The success template used during fallback auth.
+        self.fallback_success_template = self.read_templates(
+            ["auth_success.html"], autoescape=True
+        )[0]
+
     def generate_config_section(self, generate_secrets=False, **kwargs):
         if generate_secrets:
             registration_shared_secret = 'registration_shared_secret: "%s"' % (