Clarify the `account_validity` and `email` sections of the sample configuration. (#6685)

Generally try to make this more comprehensible, and make it match the
conventions.

I've removed the documentation for all the settings which allow you to change
the names of the template files, because I can't really see why they are
useful.

3 files changed, 167 insertions, 140 deletions

diff --git a/synapse/config/emailconfig.py b/synapse/config/emailconfig.py
index 35756bed87..74853f9faa 100644
--- a/synapse/config/emailconfig.py
+++ b/synapse/config/emailconfig.py
@@ -37,10 +37,12 @@ class EmailConfig(Config):
 
         self.email_enable_notifs = False
 
-        email_config = config.get("email", {})
+        email_config = config.get("email")
+        if email_config is None:
+            email_config = {}
 
-        self.email_smtp_host = email_config.get("smtp_host", None)
-        self.email_smtp_port = email_config.get("smtp_port", None)
+        self.email_smtp_host = email_config.get("smtp_host", "localhost")
+        self.email_smtp_port = email_config.get("smtp_port", 25)
         self.email_smtp_user = email_config.get("smtp_user", None)
         self.email_smtp_pass = email_config.get("smtp_pass", None)
         self.require_transport_security = email_config.get(
@@ -74,9 +76,9 @@ class EmailConfig(Config):
         self.email_template_dir = os.path.abspath(template_dir)
 
         self.email_enable_notifs = email_config.get("enable_notifs", False)
-        account_validity_renewal_enabled = config.get("account_validity", {}).get(
-            "renew_at"
-        )
+
+        account_validity_config = config.get("account_validity") or {}
+        account_validity_renewal_enabled = account_validity_config.get("renew_at")
 
         self.threepid_behaviour_email = (
             # Have Synapse handle the email sending if account_threepid_delegates.email
@@ -278,7 +280,9 @@ class EmailConfig(Config):
             self.email_notif_for_new_users = email_config.get(
                 "notif_for_new_users", True
             )
-            self.email_riot_base_url = email_config.get("riot_base_url", None)
+            self.email_riot_base_url = email_config.get(
+                "client_base_url", email_config.get("riot_base_url", None)
+            )
 
         if account_validity_renewal_enabled:
             self.email_expiry_template_html = email_config.get(
@@ -294,107 +298,111 @@ class EmailConfig(Config):
                     raise ConfigError("Unable to find email template file %s" % (p,))
 
     def generate_config_section(self, config_dir_path, server_name, **kwargs):
-        return """
-        # Enable sending emails for password resets, notification events or
-        # account expiry notices
-        #
-        # If your SMTP server requires authentication, the optional smtp_user &
-        # smtp_pass variables should be used
-        #
-        #email:
-        #   enable_notifs: false
-        #   smtp_host: "localhost"
-        #   smtp_port: 25 # SSL: 465, STARTTLS: 587
-        #   smtp_user: "exampleusername"
-        #   smtp_pass: "examplepassword"
-        #   require_transport_security: false
-        #
-        #   # notif_from defines the "From" address to use when sending emails.
-        #   # It must be set if email sending is enabled.
-        #   #
-        #   # The placeholder '%(app)s' will be replaced by the application name,
-        #   # which is normally 'app_name' (below), but may be overridden by the
-        #   # Matrix client application.
-        #   #
-        #   # Note that the placeholder must be written '%(app)s', including the
-        #   # trailing 's'.
-        #   #
-        #   notif_from: "Your Friendly %(app)s homeserver <noreply@example.com>"
-        #
-        #   # app_name defines the default value for '%(app)s' in notif_from. It
-        #   # defaults to 'Matrix'.
-        #   #
-        #   #app_name: my_branded_matrix_server
-        #
-        #   # Enable email notifications by default
-        #   #
-        #   notif_for_new_users: true
-        #
-        #   # Defining a custom URL for Riot is only needed if email notifications
-        #   # should contain links to a self-hosted installation of Riot; when set
-        #   # the "app_name" setting is ignored
-        #   #
-        #   riot_base_url: "http://localhost/riot"
-        #
-        #   # Configure the time that a validation email or text message code
-        #   # will expire after sending
-        #   #
-        #   # This is currently used for password resets
-        #   #
-        #   #validation_token_lifetime: 1h
-        #
-        #   # Template directory. All template files should be stored within this
-        #   # directory. If not set, default templates from within the Synapse
-        #   # package will be used
-        #   #
-        #   # For the list of default templates, please see
-        #   # https://github.com/matrix-org/synapse/tree/master/synapse/res/templates
-        #   #
-        #   #template_dir: res/templates
-        #
-        #   # Templates for email notifications
-        #   #
-        #   notif_template_html: notif_mail.html
-        #   notif_template_text: notif_mail.txt
-        #
-        #   # Templates for account expiry notices
-        #   #
-        #   expiry_template_html: notice_expiry.html
-        #   expiry_template_text: notice_expiry.txt
-        #
-        #   # Templates for password reset emails sent by the homeserver
-        #   #
-        #   #password_reset_template_html: password_reset.html
-        #   #password_reset_template_text: password_reset.txt
-        #
-        #   # Templates for registration emails sent by the homeserver
-        #   #
-        #   #registration_template_html: registration.html
-        #   #registration_template_text: registration.txt
-        #
-        #   # Templates for validation emails sent by the homeserver when adding an email to
-        #   # your user account
-        #   #
-        #   #add_threepid_template_html: add_threepid.html
-        #   #add_threepid_template_text: add_threepid.txt
-        #
-        #   # Templates for password reset success and failure pages that a user
-        #   # will see after attempting to reset their password
-        #   #
-        #   #password_reset_template_success_html: password_reset_success.html
-        #   #password_reset_template_failure_html: password_reset_failure.html
-        #
-        #   # Templates for registration success and failure pages that a user
-        #   # will see after attempting to register using an email or phone
-        #   #
-        #   #registration_template_success_html: registration_success.html
-        #   #registration_template_failure_html: registration_failure.html
+        return """\
+        # Configuration for sending emails from Synapse.
         #
-        #   # Templates for success and failure pages that a user will see after attempting
-        #   # to add an email or phone to their account
-        #   #
-        #   #add_threepid_success_html: add_threepid_success.html
-        #   #add_threepid_failure_html: add_threepid_failure.html
+        email:
+          # The hostname of the outgoing SMTP server to use. Defaults to 'localhost'.
+          #
+          #smtp_host: mail.server
+
+          # The port on the mail server for outgoing SMTP. Defaults to 25.
+          #
+          #smtp_port: 587
+
+          # Username/password for authentication to the SMTP server. By default, no
+          # authentication is attempted.
+          #
+          # smtp_user: "exampleusername"
+          # smtp_pass: "examplepassword"
+
+          # Uncomment the following to require TLS transport security for SMTP.
+          # By default, Synapse will connect over plain text, and will then switch to
+          # TLS via STARTTLS *if the SMTP server supports it*. If this option is set,
+          # Synapse will refuse to connect unless the server supports STARTTLS.
+          #
+          #require_transport_security: true
+
+          # Enable sending emails for messages that the user has missed
+          #
+          #enable_notifs: false
+
+          # notif_from defines the "From" address to use when sending emails.
+          # It must be set if email sending is enabled.
+          #
+          # The placeholder '%(app)s' will be replaced by the application name,
+          # which is normally 'app_name' (below), but may be overridden by the
+          # Matrix client application.
+          #
+          # Note that the placeholder must be written '%(app)s', including the
+          # trailing 's'.
+          #
+          #notif_from: "Your Friendly %(app)s homeserver <noreply@example.com>"
+
+          # app_name defines the default value for '%(app)s' in notif_from. It
+          # defaults to 'Matrix'.
+          #
+          #app_name: my_branded_matrix_server
+
+          # Uncomment the following to disable automatic subscription to email
+          # notifications for new users. Enabled by default.
+          #
+          #notif_for_new_users: false
+
+          # Custom URL for client links within the email notifications. By default
+          # links will be based on "https://matrix.to".
+          #
+          # (This setting used to be called riot_base_url; the old name is still
+          # supported for backwards-compatibility but is now deprecated.)
+          #
+          #client_base_url: "http://localhost/riot"
+
+          # Configure the time that a validation email will expire after sending.
+          # Defaults to 1h.
+          #
+          #validation_token_lifetime: 15m
+
+          # Directory in which Synapse will try to find the template files below.
+          # If not set, default templates from within the Synapse package will be used.
+          #
+          # DO NOT UNCOMMENT THIS SETTING unless you want to customise the templates.
+          # If you *do* uncomment it, you will need to make sure that all the templates
+          # below are in the directory.
+          #
+          # Synapse will look for the following templates in this directory:
+          #
+          # * The contents of email notifications of missed events: 'notif_mail.html' and
+          #   'notif_mail.txt'.
+          #
+          # * The contents of account expiry notice emails: 'notice_expiry.html' and
+          #   'notice_expiry.txt'.
+          #
+          # * The contents of password reset emails sent by the homeserver:
+          #   'password_reset.html' and 'password_reset.txt'
+          #
+          # * HTML pages for success and failure that a user will see when they follow
+          #   the link in the password reset email: 'password_reset_success.html' and
+          #   'password_reset_failure.html'
+          #
+          # * The contents of address verification emails sent during registration:
+          #   'registration.html' and 'registration.txt'
+          #
+          # * HTML pages for success and failure that a user will see when they follow
+          #   the link in an address verification email sent during registration:
+          #   'registration_success.html' and 'registration_failure.html'
+          #
+          # * The contents of address verification emails sent when an address is added
+          #   to a Matrix account: 'add_threepid.html' and 'add_threepid.txt'
+          #
+          # * HTML pages for success and failure that a user will see when they follow
+          #   the link in an address verification email sent when an address is added
+          #   to a Matrix account: 'add_threepid_success.html' and
+          #   'add_threepid_failure.html'
+          #
+          # You can see the default templates at:
+          # https://github.com/matrix-org/synapse/tree/master/synapse/res/templates
+          #
+          #template_dir: "res/templates"
         """
 
 
diff --git a/synapse/config/push.py b/synapse/config/push.py
index 0910958649..6f2b3a7faa 100644
--- a/synapse/config/push.py
+++ b/synapse/config/push.py
@@ -35,7 +35,7 @@ class PushConfig(Config):
 
         # Now check for the one in the 'email' section and honour it,
         # with a warning.
-        push_config = config.get("email", {})
+        push_config = config.get("email") or {}
         redact_content = push_config.get("redact_content")
         if redact_content is not None:
             print(
diff --git a/synapse/config/registration.py b/synapse/config/registration.py
index ee9614c5f7..b873995a49 100644
--- a/synapse/config/registration.py
+++ b/synapse/config/registration.py
@@ -27,6 +27,8 @@ class AccountValidityConfig(Config):
     section = "accountvalidity"
 
     def __init__(self, config, synapse_config):
+        if config is None:
+            return
         self.enabled = config.get("enabled", False)
         self.renew_by_email_enabled = "renew_at" in config
 
@@ -159,23 +161,6 @@ class RegistrationConfig(Config):
         # Optional account validity configuration. This allows for accounts to be denied
         # any request after a given period.
         #
-        # ``enabled`` defines whether the account validity feature is enabled. Defaults
-        # to False.
-        #
-        # ``period`` allows setting the period after which an account is valid
-        # after its registration. When renewing the account, its validity period
-        # will be extended by this amount of time. This parameter is required when using
-        # the account validity feature.
-        #
-        # ``renew_at`` is the amount of time before an account's expiry date at which
-        # Synapse will send an email to the account's email address with a renewal link.
-        # This needs the ``email`` and ``public_baseurl`` configuration sections to be
-        # filled.
-        #
-        # ``renew_email_subject`` is the subject of the email sent out with the renewal
-        # link. ``%%(app)s`` can be used as a placeholder for the ``app_name`` parameter
-        # from the ``email`` section.
-        #
         # Once this feature is enabled, Synapse will look for registered users without an
         # expiration date at startup and will add one to every account it found using the
         # current settings at that time.
@@ -186,21 +171,55 @@ class RegistrationConfig(Config):
         # date will be randomly selected within a range [now + period - d ; now + period],
         # where d is equal to 10%% of the validity period.
         #
-        #account_validity:
-        #  enabled: true
-        #  period: 6w
-        #  renew_at: 1w
-        #  renew_email_subject: "Renew your %%(app)s account"
-        #  # Directory in which Synapse will try to find the HTML files to serve to the
-        #  # user when trying to renew an account. Optional, defaults to
-        #  # synapse/res/templates.
-        #  template_dir: "res/templates"
-        #  # HTML to be displayed to the user after they successfully renewed their
-        #  # account. Optional.
-        #  account_renewed_html_path: "account_renewed.html"
-        #  # HTML to be displayed when the user tries to renew an account with an invalid
-        #  # renewal token. Optional.
-        #  invalid_token_html_path: "invalid_token.html"
+        account_validity:
+          # The account validity feature is disabled by default. Uncomment the
+          # following line to enable it.
+          #
+          #enabled: true
+
+          # The period after which an account is valid after its registration. When
+          # renewing the account, its validity period will be extended by this amount
+          # of time. This parameter is required when using the account validity
+          # feature.
+          #
+          #period: 6w
+
+          # The amount of time before an account's expiry date at which Synapse will
+          # send an email to the account's email address with a renewal link. By
+          # default, no such emails are sent.
+          #
+          # If you enable this setting, you will also need to fill out the 'email' and
+          # 'public_baseurl' configuration sections.
+          #
+          #renew_at: 1w
+
+          # The subject of the email sent out with the renewal link. '%%(app)s' can be
+          # used as a placeholder for the 'app_name' parameter from the 'email'
+          # section.
+          #
+          # Note that the placeholder must be written '%%(app)s', including the
+          # trailing 's'.
+          #
+          # If this is not set, a default value is used.
+          #
+          #renew_email_subject: "Renew your %%(app)s account"
+
+          # Directory in which Synapse will try to find templates for the HTML files to
+          # serve to the user when trying to renew an account. If not set, default
+          # templates from within the Synapse package will be used.
+          #
+          #template_dir: "res/templates"
+
+          # File within 'template_dir' giving the HTML to be displayed to the user after
+          # they successfully renewed their account. If not set, default text is used.
+          #
+          #account_renewed_html_path: "account_renewed.html"
+
+          # File within 'template_dir' giving the HTML to be displayed when the user
+          # tries to renew an account with an invalid renewal token. If not set,
+          # default text is used.
+          #
+          #invalid_token_html_path: "invalid_token.html"
 
         # Time that a user's session remains valid for, after they log in.
         #