Support adding custom headers

CHANGELOG.md

@@ -1,3 +1,8 @@
+## 4.2.0
+  - Support adding custom headers [#57](https://github.com/logstash-plugins/logstash-output-email/pull/57)
+  - Update 'mail' dependency to ~> 2 and 'mustache' to ~> 1
+  - Remove constraint on 'mime-types'
+
 ## 4.1.1
   - Docs: Set the default_codec doc attribute.
 

docs/index.asciidoc

@@ -60,6 +60,7 @@ This plugin supports the following configuration options plus the <<plugins-{typ
 | <<plugins-{type}s-{plugin}-debug>> |<<boolean,boolean>>|No
 | <<plugins-{type}s-{plugin}-domain>> |<<string,string>>|No
 | <<plugins-{type}s-{plugin}-from>> |<<string,string>>|No
+| <<plugins-{type}s-{plugin}-custom_headers>> |<<hash,hash>>|No
 | <<plugins-{type}s-{plugin}-htmlbody>> |<<string,string>>|No
 | <<plugins-{type}s-{plugin}-password>> |<<string,string>>|No
 | <<plugins-{type}s-{plugin}-port>> |<<number,number>>|No
@@ -165,6 +166,14 @@ actual hostname of the connecting client.
 
 The fully-qualified email address for the From: field in the email.
 
+[id="plugins-{type}s-{plugin}-custom_headers"]
+===== `custom_headers` 
+
+  * Value type is <<hash,hash>>
+  * Default value is `{}`
+
+Custom headers to attach to the email.
+
 [id="plugins-{type}s-{plugin}-htmlbody"]
 ===== `htmlbody` 
 
@@ -256,4 +265,4 @@ Can be used with `body` to send multi-part emails. Takes precedence over `htmlBo
 [id="plugins-{type}s-{plugin}-common-options"]
 include::{include_path}/{type}.asciidoc[]
 
-:default_codec!:
+:default_codec!:

lib/logstash/outputs/email.rb

@@ -96,6 +96,9 @@ class LogStash::Outputs::Email < LogStash::Outputs::Base
   # NOTE: this may not be functional (KH)
   config :contenttype, :validate => :string, :default => "text/html; charset=UTF-8"
 
+  # Custom headers to attach to the email
+  config :custom_headers, :validate => :hash, :default => {}
+
   public
   def register
     require "mail"
@@ -133,7 +136,7 @@ def register
   def receive(event)
 
 
-      @logger.debug? and @logger.debug("Creating mail with these settings : ", :via => @via, :options => @options, :from => @from, :to => @to, :cc => @cc, :bcc => @bcc, :subject => @subject, :body => @body, :content_type => @contenttype, :htmlbody => @htmlbody, :attachments => @attachments)
+      @logger.debug? and @logger.debug("Creating mail with these settings : ", :via => @via, :options => @options, :from => @from, :to => @to, :cc => @cc, :bcc => @bcc, :subject => @subject, :body => @body, :content_type => @contenttype, :htmlbody => @htmlbody, :attachments => @attachments, :custom_headers => @custom_headers)
       formatedSubject = event.sprintf(@subject)
       formattedBody = event.sprintf(@body)
       formattedHtmlBody = event.sprintf(@htmlbody)
@@ -148,6 +151,10 @@ def receive(event)
       mail.bcc = event.sprintf(@bcc)
       mail.subject = formatedSubject
 
+      @custom_headers.each do |key, value|
+        mail.header[event.sprintf(key)] = event.sprintf(value)
+      end
+
       if @htmlbody.empty? and @template_file.nil?
         formattedBody.gsub!(/\\n/, "\n") # Take new line in the email
         mail.body = formattedBody

logstash-output-email.gemspec

@@ -1,7 +1,7 @@
 Gem::Specification.new do |s|
 
   s.name            = 'logstash-output-email'
-  s.version         = '4.1.1'
+  s.version         = '4.2.0'
   s.licenses        = ['Apache License (2.0)']
   s.summary         = "Sends email to a specified address when output is received"
   s.description     = "This gem is a Logstash plugin required to be installed on top of the Logstash core pipeline using $LS_HOME/bin/logstash-plugin install gemname. This gem is not a stand-alone program"
@@ -22,11 +22,8 @@ Gem::Specification.new do |s|
   # Gem dependencies
   s.add_runtime_dependency "logstash-core-plugin-api", ">= 1.60", "<= 2.99"
 
-  s.add_runtime_dependency 'mail', '~> 2.6.3'
-  # mime-types >= 3 require ruby 2.0 support
-  s.add_runtime_dependency 'mime-types', '< 3'
-
-  s.add_runtime_dependency 'mustache', '>= 0.99.8'
+  s.add_runtime_dependency 'mail', '~> 2'
+  s.add_runtime_dependency 'mustache', '~> 1'
 
   s.add_development_dependency 'logstash-devutils'
   s.add_development_dependency 'rumbster'

spec/outputs/email_spec.rb

@@ -104,5 +104,22 @@
         expect(message_observer.messages[0].body.decoded).to eq(craft_multi_part_email('', '<h1>hello</h1>', message_observer.messages[0].content_type))
       end
     end
+
+    context  "custom headers for email" do
+      it "adds custom headers" do
+        headers = { "header_1" => "header_1_value", "header_2" => "header_2_value" } 
+        subject = plugin.new("to" => "me@host",
+                     "subject" => "Hello World",
+                     "body" => "Line1\\nLine2\\nLine3",
+                     "port" => port,
+                     "custom_headers" => headers )
+        subject.register
+        subject.receive(LogStash::Event.new("message" => "hello"))
+        expect(message_observer.messages.size).to eq(1)
+        headers.each do |key, value|
+          expect(message_observer.messages[0].header[key].value).to eq(value)
+        end
+      end
+    end
   end
 end