Add email provider for sending emails.

r2/example.ini

@@ -269,6 +269,15 @@ statsd_sample_rate = 1.0
 # percentage of stats for sampling (0-100)
 stats_sample_rate = 1
 
+############################################ EMAIL
+# which email provider to use
+# options are:
+#  null - no email
+#  mailgun - use mailgun as configured for reddit.com
+#  or write your own!
+email_provider = null
+mailgun_domain =
+mailgun_api_base_url =
 
 ############################################ MEDIA STORAGE
 # which backend provider to use for media (thumbnails, subreddit stylesheets,

r2/r2/lib/app_globals.py

@@ -534,6 +534,12 @@ class Globals(object):
             "r2.provider.image_resizing",
             self.image_resizing_provider,
         )
+        self.email_provider = select_provider(
+            self.config,
+            self.pkg_resources_working_set,
+            "r2.provider.email",
+            self.email_provider,
+        )
         self.startup_timer.intermediate("providers")
 
         ################# CONFIGURATION

r2/r2/lib/providers/email/__init__.py

@@ -0,0 +1,55 @@
+# The contents of this file are subject to the Common Public Attribution
+# License Version 1.0. (the "License"); you may not use this file except in
+# compliance with the License. You may obtain a copy of the License at
+# http://code.reddit.com/LICENSE. The License is based on the Mozilla Public
+# License Version 1.1, but Sections 14 and 15 have been added to cover use of
+# software over a computer network and provide for limited attribution for the
+# Original Developer. In addition, Exhibit A has been modified to be consistent
+# with Exhibit B.
+#
+# Software distributed under the License is distributed on an "AS IS" basis,
+# WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License for
+# the specific language governing rights and limitations under the License.
+#
+# The Original Code is reddit.
+#
+# The Original Developer is the Initial Developer.  The Initial Developer of
+# the Original Code is reddit Inc.
+#
+# All portions of the code written by reddit are Copyright (c) 2006-2015 reddit
+# Inc. All Rights Reserved.
+###############################################################################
+
+class EmailProvider(object):
+    """Provider for sending emails.
+
+    """
+    def send_email(self, to_address, from_address, subject, text, reply_to,
+                       parent_email_id=None, other_email_ids=None):
+        """Send an email.
+
+        `to_address` is a string or list of string email addresses.
+
+        `from_address` is a email address.
+
+        `subject` is the email's subject.
+
+        `text` is the text of the email.
+
+        `reply_to` is the reply-to address, which will be sent as the "Reply-To"
+        email header.
+
+        `parent_email_id` is the Message-Id of the email this is a reply to (if
+        any). This is sent as the "In-Reply-To" email header.
+
+        `other_email_ids` is a list of Message-Ids of emails in the conversation
+        and including `parent_email_id`. This will be converted to a space
+        delimited string and sent as the "References" email header.
+
+        The return value is the Message-Id of the sent email.
+
+        """
+        raise NotImplementedError
+
+
+class EmailSendError(Exception): pass

r2/r2/lib/providers/email/mailgun.py

@@ -0,0 +1,85 @@
+# The contents of this file are subject to the Common Public Attribution
+# License Version 1.0. (the "License"); you may not use this file except in
+# compliance with the License. You may obtain a copy of the License at
+# http://code.reddit.com/LICENSE. The License is based on the Mozilla Public
+# License Version 1.1, but Sections 14 and 15 have been added to cover use of
+# software over a computer network and provide for limited attribution for the
+# Original Developer. In addition, Exhibit A has been modified to be consistent
+# with Exhibit B.
+#
+# Software distributed under the License is distributed on an "AS IS" basis,
+# WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License for
+# the specific language governing rights and limitations under the License.
+#
+# The Original Code is reddit.
+#
+# The Original Developer is the Initial Developer.  The Initial Developer of
+# the Original Code is reddit Inc.
+#
+# All portions of the code written by reddit are Copyright (c) 2006-2015 reddit
+# Inc. All Rights Reserved.
+###############################################################################
+
+
+import json
+
+import requests
+
+from r2.lib.configparse import ConfigValue
+from r2.lib.providers.email import (
+    EmailProvider,
+    EmailSendError,
+)
+from r2.lib.utils import tup
+
+
+class MailgunEmailProvider(EmailProvider):
+    """A provider that uses mailgun to send emails."""
+
+    config = {
+        ConfigValue.str: [
+            "mailgun_api_base_url",
+        ],
+        # This also requires the secret "mailgun_api_key"
+    }
+
+    def send_email(self, to_address, from_address, subject, text, reply_to,
+                   parent_email_id=None, other_email_ids=None):
+        from pylons import app_globals as g
+
+        message_post_url = "/".join((
+            g.mailgun_api_base_url, g.mailgun_domain, "messages"))
+
+        to_address = tup(to_address)
+        parent_email_id = parent_email_id or ''
+        other_email_ids = other_email_ids or []
+
+        response = requests.post(
+            message_post_url,
+            auth=("api", g.secrets['mailgun_api_key']),
+            data={
+                "from": from_address,
+                "to": to_address,
+                "subject": subject,
+                "text": text,
+                "o:tracking": False,    # disable link rewriting
+                "h:Reply-To": reply_to,
+                "h:In-Reply-To": parent_email_id,
+                "h:References": " ".join(other_email_ids),
+            },
+        )
+
+        if response.status_code != 200:
+            msg = "mailgun sending email failed {status}: {text}".format(
+                status=response.status_code, text=response.text)
+            raise EmailSendError(msg)
+
+        try:
+            body = json.loads(response.text)
+        except ValueError:
+            msg = "mailgun sending email bad response {status}: {text}".format(
+                status=response.status_code, text=response.text)
+            raise EmailSendError(msg)
+
+        email_id = body["id"]
+        return email_id

r2/r2/lib/providers/email/null.py

@@ -0,0 +1,33 @@
+# The contents of this file are subject to the Common Public Attribution
+# License Version 1.0. (the "License"); you may not use this file except in
+# compliance with the License. You may obtain a copy of the License at
+# http://code.reddit.com/LICENSE. The License is based on the Mozilla Public
+# License Version 1.1, but Sections 14 and 15 have been added to cover use of
+# software over a computer network and provide for limited attribution for the
+# Original Developer. In addition, Exhibit A has been modified to be consistent
+# with Exhibit B.
+#
+# Software distributed under the License is distributed on an "AS IS" basis,
+# WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License for
+# the specific language governing rights and limitations under the License.
+#
+# The Original Code is reddit.
+#
+# The Original Developer is the Initial Developer.  The Initial Developer of
+# the Original Code is reddit Inc.
+#
+# All portions of the code written by reddit are Copyright (c) 2006-2015 reddit
+# Inc. All Rights Reserved.
+###############################################################################
+
+from r2.lib.providers.email import EmailProvider
+
+
+class NullEmailProvider(EmailProvider):
+    """A no-op email provider.
+
+    """
+
+    def send_email(self, to_address, from_address, subject, text, reply_to,
+                       parent_email_id=None, other_email_ids=None):
+        return None

r2/setup.py

@@ -131,5 +131,8 @@ setup(
     imgix = r2.lib.providers.image_resizing.imgix:ImgixImageResizingProvider
     no_op = r2.lib.providers.image_resizing.no_op:NoOpImageResizingProvider
     unsplashit = r2.lib.providers.image_resizing.unsplashit:UnsplashitImageResizingProvider
+    [r2.provider.email]
+    null = r2.lib.providers.email.null:NullEmailProvider
+    mailgun = r2.lib.providers.email.mailgun:MailgunEmailProvider
     """,
 )