feat: Add compress_events option to support gzipping event payload

contract-tests/client_entity.rb

@@ -35,6 +35,7 @@ def initialize(log, config)
  opts[:all_attributes_private] = !!events[:allAttributesPrivate]
  opts[:private_attributes] = events[:globalPrivateAttributes]
  opts[:flush_interval] = (events[:flushIntervalMs] / 1_000) unless events[:flushIntervalMs].nil?
+ opts[:compress_events] = !!events[:enableGzip]
  else
  opts[:send_events] = false
  end

contract-tests/service.rb

@@ -35,6 +35,7 @@
  'tags',
  'migrations',
  'event-gzip',
+ 'optional-event-gzip',
  'event-sampling',
  'context-comparison',
  'polling-gzip',

lib/ldclient-rb/config.rb

@@ -64,6 +64,7 @@ def initialize(opts = {})
  @all_attributes_private = opts[:all_attributes_private] || false
  @private_attributes = opts[:private_attributes] || []
  @send_events = opts.has_key?(:send_events) ? opts[:send_events] : Config.default_send_events
+ @compress_events = opts.has_key?(:compress_events) ? opts[:compress_events] : Config.default_compress_events
  @context_keys_capacity = opts[:context_keys_capacity] || Config.default_context_keys_capacity
  @context_keys_flush_interval = opts[:context_keys_flush_interval] || Config.default_context_keys_flush_interval
  @data_source = opts[:data_source]
@@ -252,6 +253,17 @@ def offline?
  #
  attr_reader :send_events
 
+ #
+ # Should the event payload sent to LaunchDarkly use gzip compression. By default this is false to prevent backward
+ # breaking compatibility issues with older versions of the relay proxy.
+ #
+ # Customers not using the relay proxy are strongly encouraged to enable this feature to reduce egress bandwidth
+ # cost.
+ #
+ # @return [Boolean]
+ #
+ attr_reader :compress_events
+
  #
  # The number of context keys that the event processor can remember at any one time. This reduces the
  # amount of duplicate context details sent in analytics events.
@@ -528,6 +540,14 @@ def self.default_send_events
  true
  end
 
+ #
+ # The default value for {#compress_events}.
+ # @return [Boolean] false
+ #
+ def self.default_compress_events
+ false
+ end
+
  #
  # The default value for {#context_keys_capacity}.
  # @return [Integer] 1000

lib/ldclient-rb/impl/event_sender.rb

@@ -44,17 +44,24 @@ def send_event_data(event_data, description, is_diagnostic)
  @logger.debug { "[LDClient] sending #{description}: #{event_data}" }
  headers = {}
  headers["content-type"] = "application/json"
- headers["content-encoding"] = "gzip"
+ headers["content-encoding"] = "gzip" if @config.compress_events
  Impl::Util.default_http_headers(@sdk_key, @config).each { |k, v| headers[k] = v }
  unless is_diagnostic
  headers["X-LaunchDarkly-Event-Schema"] = CURRENT_SCHEMA_VERSION.to_s
  headers["X-LaunchDarkly-Payload-ID"] = payload_id
  end
- gzip = Zlib::GzipWriter.new(StringIO.new)
- gzip << event_data
+
+ body = event_data
+ if @config.compress_events
+ gzip = Zlib::GzipWriter.new(StringIO.new)
+ gzip << event_data
+
+ body = gzip.close.string
+ end
+
  response = http_client.request("POST", uri, {
  headers: headers,
- body: gzip.close.string,
+ body: body,
  })
  rescue StandardError => exn
  @logger.warn { "[LDClient] Error sending events: #{exn.inspect}." }

spec/http_util.rb

@@ -9,8 +9,9 @@ class StubHTTPServer
 
  @@next_port = 50000
 
- def initialize
+ def initialize(enable_compression = false)
  @port = StubHTTPServer.next_port
+ @enable_compression = enable_compression
  begin
  base_opts = {
  BindAddress: '127.0.0.1',
@@ -77,11 +78,13 @@ def record_request(req, res)
 
  def await_request_with_body
  r = @requests_queue.pop
- body = r[1]
+ request, body = r[0], r[1]
+
+ return [request, body] unless @enable_compression
 
  gz = Zlib::GzipReader.new(StringIO.new(body.to_s))
 
- [r[0], gz.read]
+ [request, gz.read]
  end
 end
 
@@ -91,8 +94,8 @@ def method_missing(*)
  end
 end
 
-def with_server(server = nil)
- server = StubHTTPServer.new if server.nil?
+def with_server(enable_compression = false)
+ server = StubHTTPServer.new(enable_compression)
  begin
  server.start
  yield server

spec/impl/event_sender_spec.rb

@@ -13,17 +13,38 @@ module Impl
  let(:sdk_key) { "sdk_key" }
  let(:fake_data) { '{"things":[]}' }
 
- def make_sender(server)
- make_sender_with_events_uri(server.base_uri.to_s)
+ def make_sender_with_config(config = Config.new(logger: $null_log))
+ subject.new(sdk_key, config, nil, 0.1)
  end
 
- def make_sender_with_events_uri(events_uri)
- subject.new(sdk_key, Config.new(events_uri: events_uri, logger: $null_log, application: {id: "id", version: "version"}), nil, 0.1)
+ def with_sender_and_server(enable_compression = false)
+ with_server(enable_compression) do |server|
+ config = Config.new(events_uri: server.base_uri.to_s, logger: $null_log)
+ yield make_sender_with_config(config), server
+ end
  end
 
- def with_sender_and_server
- with_server do |server|
- yield make_sender(server), server
+ it "sends analytic data with gzip compression" do
+ with_sender_and_server(true) do |es, server|
+ server.setup_ok_response("/bulk", "")
+
+ result = es.send_event_data(fake_data, "", false)
+
+ expect(result.success).to be true
+ expect(result.must_shutdown).to be false
+ expect(result.time_from_server).not_to be_nil
+
+ req, body = server.await_request_with_body
+ expect(body).to eq fake_data
+ expect(req.header).to include({
+ "authorization" => [ sdk_key ],
+ "content-type" => [ "application/json" ],
+ "user-agent" => [ "RubyClient/" + LaunchDarkly::VERSION ],
+ "x-launchdarkly-event-schema" => [ "4" ],
+ "x-launchdarkly-tags" => [ "application-id/id application-version/version" ],
+ "connection" => [ "Keep-Alive" ],
+ })
+ expect(req.header['x-launchdarkly-payload-id']).not_to eq []
  end
  end
 
@@ -123,7 +144,9 @@ def with_sender_and_server
  begin
  ENV["http_proxy"] = proxy.base_uri.to_s
 
- es = make_sender_with_events_uri(fake_target_uri)
+ config = Config.default
+ config.events_uri = fake_target_uri
+ es = make_sender_with_config(config)
 
  result = es.send_event_data(fake_data, "", false)