Adding custom header support

CHANGELOG.md

@@ -1,3 +1,6 @@
+## 4.1.0
+ - Added support for custom headers [#187](https://github.com/logstash-plugins/logstash-filter-elasticsearch/pull/187)
+
 ## 4.0.0
   - SSL settings that were marked deprecated in version `3.15.0` are now marked obsolete, and will prevent the plugin from starting.
   - These settings are:

docs/index.asciidoc

@@ -134,6 +134,7 @@ NOTE: As of version `4.0.0` of this plugin, a number of previously deprecated se
 | <<plugins-{type}s-{plugin}-ca_trusted_fingerprint>> |<<string,string>>|No
 | <<plugins-{type}s-{plugin}-cloud_auth>> |<<password,password>>|No
 | <<plugins-{type}s-{plugin}-cloud_id>> |<<string,string>>|No
+| <<plugins-{type}s-{plugin}-custom_headers>> |<<hash,hash>>|No
 | <<plugins-{type}s-{plugin}-docinfo_fields>> |<<hash,hash>>|No
 | <<plugins-{type}s-{plugin}-enable_sort>> |<<boolean,boolean>>|No
 | <<plugins-{type}s-{plugin}-fields>> |<<array,array>>|No
@@ -230,6 +231,16 @@ Cloud ID, from the Elastic Cloud web console. If set `hosts` should not be used.
 For more info, check out the
 {logstash-ref}/connecting-to-cloud.html[Logstash-to-Cloud documentation].
 
+
+[id="plugins-{type}s-{plugin}-custom_headers"]
+===== `custom_headers`
+
+  * Value type is <<hash,hash>>
+  * Default value is empty
+
+Pass a set of key value pairs as the headers sent in each request to Elasticsearch.
+These custom headers will override any headers previously set by the plugin such as the User Agent or Authorization headers.
+
 [id="plugins-{type}s-{plugin}-docinfo_fields"]
 ===== `docinfo_fields` 
 

lib/logstash/filters/elasticsearch.rb

@@ -32,6 +32,9 @@ class LogStash::Filters::Elasticsearch < LogStash::Filters::Base
   # Array of fields to copy from old event (found via elasticsearch) into new event
   config :fields, :validate => :array, :default => {}
 
+  # Custom headers for Elasticsearch requests
+  config :custom_headers, :validate => :hash, :default => {}
+
   # Hash of docinfo fields to copy from old event (found via elasticsearch) into new event
   config :docinfo_fields, :validate => :hash, :default => {}
 

lib/logstash/filters/elasticsearch/client.rb

@@ -20,13 +20,16 @@ def initialize(logger, hosts, options = {})
         api_key = options.fetch(:api_key, nil)
         proxy = options.fetch(:proxy, nil)
         user_agent = options[:user_agent]
+        custom_headers = options[:custom_headers]
+
 
         transport_options = { }
         transport_options[:headers] = options.fetch(:serverless, false) ?  DEFAULT_EAV_HEADER.dup : {}
         transport_options[:headers].merge!(setup_basic_auth(user, password))
         transport_options[:headers].merge!(setup_api_key(api_key))
         transport_options[:headers].merge!({ 'user-agent' => "#{user_agent}" })
         transport_options[:headers].merge!(INTERNAL_ORIGIN_HEADER)
+        transport_options[:headers].merge!(custom_headers) unless custom_headers.empty?
 
         transport_options[:pool_max] = 1000
         transport_options[:pool_max_per_route] = 100

logstash-filter-elasticsearch.gemspec

@@ -1,7 +1,7 @@
 Gem::Specification.new do |s|
 
   s.name            = 'logstash-filter-elasticsearch'
-  s.version         = '4.0.0'
+  s.version         = '4.1.0'
   s.licenses        = ['Apache License (2.0)']
   s.summary         = "Copies fields from previous log events in Elasticsearch to current events "
   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"

spec/filters/elasticsearch_spec.rb

@@ -333,6 +333,30 @@
       end
     end
 
+    context "with custom headers" do
+      let(:config) do
+        {
+          "query" => "*",
+          "custom_headers" => { "Custom-Header-1" => "Custom Value 1", "Custom-Header-2" => "Custom Value 2" }
+        }
+      end
+
+      let(:plugin) { LogStash::Filters::Elasticsearch.new(config) }
+      let(:client_double) { double("client") }
+      let(:transport_double) { double("transport", options: { transport_options: { headers: config["custom_headers"] } }) }
+
+      before do
+        allow(plugin).to receive(:get_client).and_return(client_double)
+        allow(client_double).to receive(:client).and_return(transport_double)
+      end
+
+      it "sets custom headers" do
+        plugin.register
+        client = plugin.send(:get_client).client
+        expect(client.options[:transport_options][:headers]).to match(hash_including(config["custom_headers"]))
+      end
+    end
+
     context "if query is on nested field" do
       let(:config) do
         {