Content-Type can now be set for email-ext publisher

The email-ext publisher was always sending email using the default
content type which is server wide.  This tiny patch let us overwrite the
content-type on a job basis.

The YAML possible values are 'html' or 'text' to force the content-type
to one of the two modes.

Change-Id: Id66bc3369332c389dfb6318113392694a4f98aad

jenkins_jobs/modules/publishers.py

@@ -1382,6 +1382,9 @@ def email_ext(parser, xml_parent, data):
     :arg str recipients: Comma separated list of emails
     :arg str reply-to: Comma separated list of emails that should be in
         the Reply-To header for this project (default is $DEFAULT_RECIPIENTS)
+    :arg str content-type: The content type of the emails sent. If not set, the
+        Jenkins plugin uses the value set on the main configuration page.
+        Possible values: 'html', 'text' or 'default' (default 'default')
     :arg str subject: Subject for the email, can include variables like
         ${BUILD_NUMBER} or even groovy or javascript code
     :arg str body: Content for the body of the email, can include variables
@@ -1447,7 +1450,18 @@ def email_ext(parser, xml_parent, data):
         base_email_ext(parser, ctrigger, data, 'StillUnstableTrigger')
     if data.get('pre-build', False):
         base_email_ext(parser, ctrigger, data, 'PreBuildTrigger')
-    XML.SubElement(emailext, 'contentType').text = 'default'
+
+    content_type_mime = {
+        'text': 'text/plain',
+        'html': 'text/html',
+        'default': 'default',
+    }
+    ctype = data.get('content-type', 'default')
+    if ctype not in content_type_mime:
+        raise JenkinsJobsException('email-ext content type must be one of: %s'
+                                   % ', '.join(content_type_mime.keys()))
+    XML.SubElement(emailext, 'contentType').text = content_type_mime[ctype]
+
     XML.SubElement(emailext, 'defaultSubject').text = data.get(
         'subject', '$DEFAULT_SUBJECT')
     XML.SubElement(emailext, 'defaultContent').text = data.get(

tests/publishers/fixtures/email-ext001.xml

@@ -137,7 +137,7 @@
           </email>
         </hudson.plugins.emailext.plugins.trigger.PreBuildTrigger>
       </configuredTriggers>
-      <contentType>default</contentType>
+	  <contentType>text/html</contentType>
       <defaultSubject>Subject for Build ${BUILD_NUMBER}</defaultSubject>
       <defaultContent>The build has finished</defaultContent>
       <attachmentsPattern>*/foo*.log</attachmentsPattern>

tests/publishers/fixtures/email-ext001.yaml

@@ -2,6 +2,7 @@ publishers:
   - email-ext:
       recipients: foo@example.com, bar@example.com
       reply-to: foo@example.com
+      content-type: html
       subject: Subject for Build ${BUILD_NUMBER}
       body: The build has finished
       attach-build-log: false