feat: allow payload compression in POST requests

- only done if custom_http_headers config includes {'Content-Encoding' => 'gzip'}
- only allow gzip.
- 'Content-Encoding' header will get dropped in GET requests.
- undocumented feature.

lib/unleash/util/http.rb

@@ -1,5 +1,7 @@
 require 'net/http'
 require 'uri'
+require 'zlib'
+require 'stringio'
 
 module Unleash
  module Util
@@ -8,6 +10,7 @@ def self.get(uri, etag = nil, headers_override = nil)
  http = http_connection(uri)
 
  request = Net::HTTP::Get.new(uri.request_uri, http_headers(etag, headers_override))
+ request.delete('Content-Encoding')
 
  http.request(request)
  end
@@ -16,7 +19,15 @@ def self.post(uri, body)
  http = http_connection(uri)
 
  request = Net::HTTP::Post.new(uri.request_uri, http_headers)
- request.body = body
+ request_body =
+ if request['Content-Encoding'] == 'gzip'
+ request_body_writer = Zlib::GzipWriter.new(StringIO.new)
+ request_body_writer << body
+ request_body_writer.close.string
+ else
+ body
+ end
+ request.body = request_body
 
  http.request(request)
  end
@@ -32,6 +43,7 @@ def self.http_connection(uri)
 
  # @param etag [String, nil]
  # @param headers_override [Hash, nil]
+ # @return [Hash]
  def self.http_headers(etag = nil, headers_override = nil)
  Unleash.logger.debug "ETag: #{etag}" unless etag.nil?
 

spec/unleash/client_spec.rb

@@ -1,3 +1,6 @@
+require 'stringio'
+require 'zlib'
+
 RSpec.describe Unleash::Client do
  after do
  WebMock.reset!
@@ -108,6 +111,107 @@
  ).to have_been_made.once
  end
 
+ it "The compress http header compresses post requests when initializing client" do
+ WebMock.stub_request(:post, "http://test-url/client/register")
+ .with(
+ headers: {
+ 'Accept' => '*/*',
+ 'Content-Type' => 'application/json',
+ 'Content-Encoding' => 'gzip',
+ 'Accept-Encoding' => 'gzip;q=1.0,deflate;q=0.6,identity;q=0.3',
+ 'User-Agent' => 'Ruby',
+ 'X-Api-Key' => '123'
+ }
+ )
+ .to_return(status: 200, body: "", headers: {})
+ WebMock.stub_request(:post, "http://test-url/client/metrics")
+ .with(
+ headers: {
+ 'Accept' => '*/*',
+ 'Accept-Encoding' => 'gzip;q=1.0,deflate;q=0.6,identity;q=0.3',
+ 'Content-Type' => 'application/json',
+ 'Content-Encoding' => 'gzip',
+ 'User-Agent' => 'Ruby'
+ }
+ )
+ .to_return(status: 200, body: "", headers: {})
+
+ simple_features = {
+ "version": 1,
+ "features": [
+ {
+ "name": "Feature.A",
+ "description": "Enabled toggle",
+ "enabled": true,
+ "strategies": [{ "name": "default" }]
+ }
+ ]
+ }
+ WebMock.stub_request(:get, "http://test-url/client/features")
+ .with(
+ headers: {
+ 'Accept' => '*/*',
+ 'Accept-Encoding' => 'gzip;q=1.0,deflate;q=0.6,identity;q=0.3',
+ 'Content-Type' => 'application/json',
+ 'Unleash-Appname' => 'my-test-app',
+ 'Unleash-Instanceid' => 'rspec/test',
+ 'User-Agent' => 'Ruby',
+ 'X-Api-Key' => '123'
+ }
+ )
+ .to_return(status: 200, body: simple_features.to_json, headers: {})
+
+ unleash_client = Unleash::Client.new(
+ url: 'http://test-url/',
+ app_name: 'my-test-app',
+ instance_id: 'rspec/test',
+ custom_http_headers: { 'X-API-KEY' => '123', 'Content-Encoding' => 'gzip' }
+ )
+
+ expect(unleash_client).to be_a(Unleash::Client)
+
+ expect(
+ a_request(:post, "http://test-url/client/register")
+ .with(headers: {
+ 'Content-Type': 'application/json',
+ 'Content-Encoding': 'gzip',
+ 'X-API-KEY': '123',
+ 'UNLEASH-APPNAME': 'my-test-app',
+ 'UNLEASH-INSTANCEID': 'rspec/test'
+ })
+ ).to have_been_made.once
+
+ expect(
+ a_request(:get, "http://test-url/client/features")
+ .with(headers: {
+ 'Content-Type': 'application/json',
+ 'X-API-KEY': '123',
+ 'UNLEASH-APPNAME': 'my-test-app',
+ 'UNLEASH-INSTANCEID': 'rspec/test'
+ })
+ ).to have_been_made.once
+
+ # Test now sending of metrics
+ # Sending metrics, if they have been evaluated:
+ unleash_client.is_enabled?("Feature.A")
+ unleash_client.get_variant("Feature.A")
+ Unleash.reporter.post
+ expect(
+ a_request(:post, "http://test-url/client/metrics")
+ .with(headers: {
+ 'Content-Type': 'application/json',
+ 'Content-Encoding': 'gzip',
+ 'X-API-KEY': '123',
+ 'UNLEASH-APPNAME': 'my-test-app',
+ 'UNLEASH-INSTANCEID': 'rspec/test'
+ })
+ .with do |request|
+ uncompressed_request_body = Zlib::GzipReader.wrap(StringIO.new(request.body), &:read)
+ JSON.parse(uncompressed_request_body)['bucket']['toggles']['Feature.A']['yes'] == 2
+ end
+ ).to have_been_made.once
+ end
+
  it "should load/use correct variants from the unleash server" do
  WebMock.stub_request(:post, "http://test-url/client/register")
  .with(