Support sending logs to Datadog v2 endpoints.

This PR is also adding a public variable containing current Gem version.

.gitignore

@@ -40,5 +40,4 @@ foo/
 *.iml
 .idea/
 
-fluent/
 Gemfile.lock

fluent-plugin-datadog.gemspec

@@ -7,16 +7,18 @@
 lib = File.expand_path('../lib', __FILE__)
 $LOAD_PATH.unshift(lib) unless $LOAD_PATH.include?(lib)
 
+require "fluent/plugin/version.rb"
+
 Gem::Specification.new do |spec|
   spec.name          = "fluent-plugin-datadog"
-  spec.version       = "0.13.0"
+  spec.version       = Datadog::FluentPlugin::GEM_VERSION
   spec.authors       = ["Datadog Solutions Team"]
   spec.email         = ["support@datadoghq.com"]
   spec.summary       = "Datadog output plugin for Fluent event collector"
   spec.homepage      = "http://datadoghq.com"
   spec.license       = "Apache-2.0"
 
-  spec.files         = [".gitignore", "Gemfile", "LICENSE", "README.md", "Rakefile", "fluent-plugin-datadog.gemspec", "lib/fluent/plugin/out_datadog.rb"]
+  spec.files         = [".gitignore", "Gemfile", "LICENSE", "README.md", "Rakefile", "fluent-plugin-datadog.gemspec", "lib/fluent/plugin/version.rb", "lib/fluent/plugin/out_datadog.rb"]
   spec.executables   = spec.files.grep(%r{^bin/}) { |f| File.basename(f) }
   spec.test_files    = spec.files.grep(%r{^(test|spec|features)/})
   spec.require_paths = ["lib"]

lib/fluent/plugin/out_datadog.rb

@@ -9,6 +9,8 @@
 require "zlib"
 require "fluent/plugin/output"
 
+require_relative "version"
+
 class Fluent::DatadogOutput < Fluent::Plugin::Output
   class RetryableError < StandardError;
   end
@@ -50,6 +52,7 @@ class RetryableError < StandardError;
   config_param :compression_level, :integer, :default => 6
   config_param :no_ssl_validation, :bool, :default => false
   config_param :http_proxy, :string, :default => nil
+  config_param :force_v1_routes, :bool, :default => false
 
   # Format settings
   config_param :use_json, :bool, :default => true
@@ -89,7 +92,7 @@ def formatted_to_msgpack_binary?
 
   def start
     super
-    @client = new_client(log, @api_key, @use_http, @use_ssl, @no_ssl_validation, @host, @ssl_port, @port, @http_proxy, @use_compression)
+    @client = new_client(log, @api_key, @use_http, @use_ssl, @no_ssl_validation, @host, @ssl_port, @port, @http_proxy, @use_compression, @force_v1_routes)
   end
 
   def shutdown
@@ -261,9 +264,9 @@ def gzip_compress(payload, compression_level)
   end
 
   # Build a new transport client
-  def new_client(logger, api_key, use_http, use_ssl, no_ssl_validation, host, ssl_port, port, http_proxy, use_compression)
+  def new_client(logger, api_key, use_http, use_ssl, no_ssl_validation, host, ssl_port, port, http_proxy, use_compression, force_v1_routes)
     if use_http
-      DatadogHTTPClient.new logger, use_ssl, no_ssl_validation, host, ssl_port, port, http_proxy, use_compression, api_key
+      DatadogHTTPClient.new logger, use_ssl, no_ssl_validation, host, ssl_port, port, http_proxy, use_compression, api_key, force_v1_routes
     else
       DatadogTCPClient.new logger, use_ssl, no_ssl_validation, host, ssl_port, port
     end
@@ -301,20 +304,29 @@ class DatadogHTTPClient < DatadogClient
     require 'net/http'
     require 'net/http/persistent'
 
-    def initialize(logger, use_ssl, no_ssl_validation, host, ssl_port, port, http_proxy, use_compression, api_key)
+    def initialize(logger, use_ssl, no_ssl_validation, host, ssl_port, port, http_proxy, use_compression, api_key, force_v1_routes = false)
       @logger = logger
       protocol = use_ssl ? "https" : "http"
       port = use_ssl ? ssl_port : port
-      @uri = URI("#{protocol}://#{host}:#{port.to_s}/v1/input/#{api_key}")
+      if force_v1_routes
+        @uri = URI("#{protocol}://#{host}:#{port.to_s}/v1/input/#{api_key}")
+      else
+        @uri = URI("#{protocol}://#{host}:#{port.to_s}/api/v2/logs")
+      end
       proxy_uri = :ENV
       if http_proxy
         proxy_uri = URI.parse(http_proxy)
       elsif ENV['HTTP_PROXY'] || ENV['http_proxy']
         logger.info("Using HTTP proxy defined in `HTTP_PROXY`/`http_proxy` env vars")
       end
-      logger.info("Starting HTTP connection to #{protocol}://#{host}:#{port.to_s} with compression " + (use_compression ? "enabled" : "disabled"))
+      logger.info("Starting HTTP connection to #{protocol}://#{host}:#{port.to_s} with compression " + (use_compression ? "enabled" : "disabled") + (force_v1_routes ? " using v1 routes" : " using v2 routes"))
       @client = Net::HTTP::Persistent.new name: "fluent-plugin-datadog-logcollector", proxy: proxy_uri
       @client.verify_mode = OpenSSL::SSL::VERIFY_NONE if no_ssl_validation
+      unless force_v1_routes
+        @client.override_headers["DD-API-KEY"] = api_key
+        @client.override_headers["DD-EVP-ORIGIN"] = "fluent"
+        @client.override_headers["DD-EVP-ORIGIN-VERSION"] = Datadog::FluentPlugin::GEM_VERSION
+      end
       @client.override_headers["Content-Type"] = "application/json"
       if use_compression
         @client.override_headers["Content-Encoding"] = "gzip"

lib/fluent/plugin/version.rb

@@ -0,0 +1,7 @@
+# frozen_string_literal: true
+
+module Datadog
+  class FluentPlugin
+    GEM_VERSION = '0.14.0'
+  end
+end