Merge pull request #7 from amaabca/ado4905-cloudwatchlogs-rate-limit

Version 0.5.0 | CloudWatchLogs API Rate Limits

spec/subscribe/lambda/function_spec.rb

@@ -4,7 +4,7 @@
   let(:tags) { { 'test' => 'true' } }
   let(:destination_arn) { ENV.fetch('DESTINATION_ARN') }
   let(:lambda) { described_class.build_lambda_client(stub_responses: true) }
-  let(:cloudwatch) { Aws::CloudWatchLogs::Client.new(stub_responses: true) }
+  let(:cloudwatch) { described_class.build_cloudwatchlogs_client(stub_responses: true) }
   let(:tags_stub) { lambda.stub_data(:list_tags, tags: tags) }
   let(:function_one_arn) { 'arn:aws:lambda:us-west-2:123456789012:function:One' }
   let(:function_two_arn) { 'arn:aws:lambda:us-west-2:123456789012:function:Two' }
@@ -263,5 +263,33 @@
       expect(value.fetch(:changed)).to eq(['two'])
       expect(value.fetch(:skipped)).to eq(['one'])
     end
+
+    context 'when hitting an API rate limit for DescribeSubscriptionFilters' do
+      before(:each) do
+        cloudwatch.handlers.add(Aws::Plugins::RetryErrors::Handler)
+        cloudwatch.stub_responses(
+          :describe_subscription_filters,
+          [
+            'ThrottlingException',
+            'ThrottlingException',
+            'ThrottlingException',
+            log_group_one_subscription
+          ]
+        )
+      end
+
+      it 'sleeps with exponential backoff' do
+        # 1 -> throttle
+        # wait 1s
+        # 2 -> throttle
+        # wait 2s
+        # 3 -> throttle
+        # wait 2s
+        # 4 -> success
+        # >= 5s total
+        time = Benchmark.measure { described_class.subscribe_all!(lambda, cloudwatch) }
+        expect(time.real >= 5).to be true
+      end
+    end
   end
 end

subscribe/lambda/function.rb

@@ -8,7 +8,7 @@ class Function
       attr_accessor :name, :arn, :tags, :lambda, :cloudwatch
 
       class << self
-        def all(lambda = build_lambda_client, cloudwatch = Aws::CloudWatchLogs::Client.new)
+        def all(lambda = build_lambda_client, cloudwatch = build_cloudwatchlogs_client)
           all_functions(lambda).map do |function|
             new(
               name: function.function_name,
@@ -19,7 +19,7 @@ def all(lambda = build_lambda_client, cloudwatch = Aws::CloudWatchLogs::Client.n
           end
         end
 
-        def subscribe_all!(lambda = build_lambda_client, cloudwatch = Aws::CloudWatchLogs::Client.new)
+        def subscribe_all!(lambda = build_lambda_client, cloudwatch = build_cloudwatchlogs_client)
           data = {
             timestamp: Time.now.iso8601,
             event: 'log.info',
@@ -36,15 +36,17 @@ def subscribe_all!(lambda = build_lambda_client, cloudwatch = Aws::CloudWatchLog
           end
         end
 
-        def build_lambda_client(opts = {})
+        def retry_opts
           # retries: 1s -> 2s -> 2s -> fail
-          Aws::Lambda::Client.new(
-            {
-              retry_limit: 3,
-              retry_base_delay: 1,
-              retry_max_delay: 2
-            }.merge(opts)
-          )
+          { retry_limit: 3, retry_base_delay: 1, retry_max_delay: 2 }
+        end
+
+        def build_lambda_client(opts = {})
+          Aws::Lambda::Client.new(retry_opts.merge(opts))
+        end
+
+        def build_cloudwatchlogs_client(opts = {})
+          Aws::CloudWatchLogs::Client.new(retry_opts.merge(opts))
         end
 
         private

template.yml

@@ -19,7 +19,7 @@ Metadata:
       - forwarder
       - lambda
     HomePageUrl: https://github.com/amaabca/cloudwatch_loggly
-    SemanticVersion: 0.4.0
+    SemanticVersion: 0.5.0
     SourceCodeUrl: https://github.com/amaabca/cloudwatch_loggly
 
 Parameters: