Ability to embed custom images in notifications

README.md

@@ -16,7 +16,7 @@ The project is currently in alpha status, but will soon be used in a productive
 * BeautifulSoup <https://www.crummy.com/software/BeautifulSoup/>
 
 ## Configuration
-The pyquarantine module uses an INI-style configuration file. The sections are described below.
+The pyquarantine module uses an INI-style configuration file. The sections are described below. If you have to specify a path in the config, you can always use a relative path to the last loaded config file.
 
 ### Section "global"
 Any available configuration option can be set in the global section as default instead of in a quarantine section.  
@@ -85,10 +85,12 @@ The following configuration options are mandatory in each quarantine section:
   * **notification_email_subject**  
     Notification e-mail subject.
   * **notification_email_template**  
-    Notification e-mail template to use.
+    Path to the notification e-mail template. It is hold in memory during runtime.
   * **notification_email_replacement_img**  
-    An image to replace images in e-mail.
+    Path to the image to replace images in e-mails. It is hold in memory during runtime. Leave it empty to disable.
-
+  * **notification_email_embedded_imgs**  
+    Comma-separated list of images to attach to the notification e-mail. The Content-ID of each image will be set to the filename, so you can reference it from the e-mail template. All images are hold in memory during runtime. 
+    Leave empty to disable.
 
 ### Actions
 Every quarantine responds with a milter-action if an e-mail header matches the configured regular expression.  

docs/pyquarantine.conf.example

@@ -94,18 +94,26 @@ notification_email_subject = Spam Quarantine Notification
 # Notes:  Set the template used when sending notification emails.
 #         A relative path to this config file can be used.
 #         This option is needed by notification type 'email'.
-# Values: [ TEMPLATE_FILE ]
+# Values: [ TEMPLATE_PATH ]
 #
 notification_email_template = templates/notification.template
 
 # Option: notification_email_replacement_img
-# Notes:  Set the replacement image for images within emails.
+# Notes:  Set the path to the replacement image for img tags within emails.
 #         A relative path to this config file can be used.
 #         This option is needed by notification type 'email'.
-# Values: [ IMAGE_FILE ]
+# Values: [ IMAGE_PATH ]
 #
 notification_email_replacement_img = templates/removed.png
 
+# Option: notification_email_embedded_imgs
+# Notes:  Set a list of paths to images to embed in e-mails (comma-separated).
+#         Relative paths to this config file can be used.
+#         This option is needed by notification type 'email'.
+# Values: [ IMAGE_PATH ]
+#
+notification_email_embedded_imgs = templates/logo.png
+
 # Option: whitelist_type
 # Notes:  Set the whitelist type.
 # Values: [ db | none ]

pyquarantine/notifications.py

@@ -21,6 +21,7 @@ from cgi import escape
 from email.mime.multipart import MIMEMultipart
 from email.mime.text import MIMEText
 from email.mime.image import MIMEImage
+from os.path import basename
 
 from pyquarantine import mailer
 
@@ -105,7 +106,7 @@ class EMailNotification(BaseNotification):
         super(EMailNotification, self).__init__(global_config, config, configtest)
 
         # check if mandatory options are present in config
-        for option in ["smtp_host", "smtp_port", "notification_email_from", "notification_email_subject", "notification_email_template", "notification_email_replacement_img"]:
+        for option in ["smtp_host", "smtp_port", "notification_email_from", "notification_email_subject", "notification_email_template", "notification_email_replacement_img", "notification_email_embedded_imgs"]:
             if option not in self.config.keys() and option in self.global_config.keys():
                 self.config[option] = self.global_config[option]
             if option not in self.config.keys():
@@ -122,13 +123,31 @@ class EMailNotification(BaseNotification):
         except IOError as e:
             raise RuntimeError("error reading template: {}".format(e))
 
-        # read email replacement image
+        # read email replacement image if specified
+        replacement_img_path = self.config["notification_email_replacement_img"].strip()
+        if replacement_img_path:
             try:
-            self.replacement_img = MIMEImage(open(self.config["notification_email_replacement_img"], "rb").read())
+                self.replacement_img = MIMEImage(open(replacement_img_path, "rb").read())
             except IOError as e:
                 raise RuntimeError("error reading replacement image: {}".format(e))
             else:
                 self.replacement_img.add_header("Content-ID", "<removed_for_security_reasons>")
+        else:
+            self.replacement_img = None
+
+        # read images to embed if specified
+        embedded_img_paths = [ p.strip() for p in self.config["notification_email_embedded_imgs"].split(",") if p]
+        self.embedded_imgs = []
+        for img_path in embedded_img_paths:
+            # read image
+            try:
+                img = MIMEImage(open(img_path, "rb").read())
+            except IOError as e:
+                raise RuntimeError("error reading image: {}".format(e))
+            else:
+                img.add_header("Content-ID", "<{}>".format(basename(img_path)))
+                self.embedded_imgs.append(img)
+
 
     def get_text(self, queueid, part):
         "Get the mail text in html form from email part."
@@ -214,12 +233,13 @@ class EMailNotification(BaseNotification):
         soup = self.get_html_text_part(queueid, email.message_from_binary_file(fp))
 
         # replace picture sources
-        picture_replaced = False
+        image_replaced = False
+        if self.replacement_img:
             for element in soup("img"):
                 if "src" in element.attrs.keys():
                     self.logger.debug("{}: replacing image: {}".format(queueid, element["src"]))
                 element["src"] = "cid:removed_for_security_reasons"
-            picture_replaced = True
+                image_replaced = True
 
         # sanitizing email text of original email
         sanitized_text = self.sanitize(queueid, soup)
@@ -247,10 +267,14 @@ class EMailNotification(BaseNotification):
             msg["Date"] = email.utils.formatdate()
             msg.attach(MIMEText(htmltext, "html", 'UTF-8'))
 
-            if picture_replaced:
+            if image_replaced:
                 self.logger.debug("{}: attaching notification_replacement_img".format(queueid))
                 msg.attach(self.replacement_img)
 
+            for img in self.embedded_imgs:
+                self.logger.debug("{}: attaching imgage".format(queueid))
+                msg.attach(img)
+
             self.logger.debug("{}: sending notification email to: {}".format(queueid, recipient))
             if synchronous:
                 try: