chore(fluentd): resolve rubocop failures

clients/cmd/fluentd/.rubocop.yml

@@ -1,6 +1,7 @@
 require: rubocop-rspec
 
 AllCops:
+  TargetRubyVersion: 2.7
   NewCops: disable
   Exclude:
     - 'bin/**'

clients/cmd/fluentd/docker/Gemfile

@@ -2,5 +2,5 @@
 
 source 'https://rubygems.org'
 
-gem 'fluent-plugin-multi-format-parser', '~>1.0.0'
 gem 'fluentd', '1.9.0'
+gem 'fluent-plugin-multi-format-parser', '~>1.0.0'

clients/cmd/fluentd/fluent-plugin-grafana-loki.gemspec

@@ -13,10 +13,12 @@ Gem::Specification.new do |spec|
   spec.homepage      = 'https://github.com/grafana/loki/'
   spec.license       = 'Apache-2.0'
 
+  spec.required_ruby_version = '~> 2.7'
+
   # test_files, files  = `git ls-files -z`.split("\x0").partition do |f|
   #   f.match(%r{^(test|spec|features)/})
   # end
-  spec.files         = Dir.glob('{bin,lib}/**/*') + %w[LICENSE README.md]
+  spec.files         = Dir['{bin,lib}/**/*'] + %w[LICENSE README.md]
   spec.executables   = spec.files.grep(%r{^exe/}) { |f| File.basename(f) }
   spec.require_paths = ['lib']
 

clients/cmd/fluentd/lib/fluent/plugin/out_loki.rb

@@ -81,10 +81,11 @@ class LogPostError < StandardError; end
         config_set_default :chunk_keys, []
       end
 
-      def configure(conf) # rubocop:disable Metrics/CyclomaticComplexity
+      # rubocop:disable Metrics/AbcSize, Metrics/CyclomaticComplexity, Metrics/PerceivedComplexity
+      def configure(conf)
         compat_parameters_convert(conf, :buffer)
         super
-        @uri = URI.parse(@url + '/loki/api/v1/push')
+        @uri = URI.parse("#{@url}/loki/api/v1/push")
         unless @uri.is_a?(URI::HTTP) || @uri.is_a?(URI::HTTPS)
           raise Fluent::ConfigError, 'URL parameter must have HTTP/HTTPS scheme'
         end
@@ -108,25 +109,24 @@ def configure(conf) # rubocop:disable Metrics/CyclomaticComplexity
           validate_client_cert_key
         end
 
-        raise "bearer_token_file #{@bearer_token_file} not found" if !@bearer_token_file.nil? && !File.exist?(@bearer_token_file)
+        if !@bearer_token_file.nil? && !File.exist?(@bearer_token_file)
+          raise "bearer_token_file #{@bearer_token_file} not found"
+        end
 
         @auth_token_bearer = nil
-        if !@bearer_token_file.nil?
-          if !File.exist?(@bearer_token_file)
-            raise "bearer_token_file #{@bearer_token_file} not found"
-          end
+        unless @bearer_token_file.nil?
+          raise "bearer_token_file #{@bearer_token_file} not found" unless File.exist?(@bearer_token_file)
 
           # Read the file once, assume long-lived authentication token.
           @auth_token_bearer = File.read(@bearer_token_file)
-          if @auth_token_bearer.empty?
-            raise "bearer_token_file #{@bearer_token_file} is empty"
-          end
+          raise "bearer_token_file #{@bearer_token_file} is empty" if @auth_token_bearer.empty?
+
           log.info "will use Bearer token from bearer_token_file #{@bearer_token_file} in Authorization header"
         end
 
-
         raise "CA certificate file #{@ca_cert} not found" if !@ca_cert.nil? && !File.exist?(@ca_cert)
       end
+      # rubocop:enable Metrics/AbcSize, Metrics/CyclomaticComplexity, Metrics/PerceivedComplexity
 
       def client_cert_configured?
         !@key.nil? && !@cert.nil?
@@ -204,8 +204,7 @@ def http_request_opts(uri)
       def generic_to_loki(chunk)
         # log.debug("GenericToLoki: converting #{chunk}")
         streams = chunk_to_loki(chunk)
-        payload = payload_builder(streams)
-        payload
+        payload_builder(streams)
       end
 
       private
@@ -215,7 +214,7 @@ def loki_http_request(body, tenant)
           @uri.request_uri
         )
         req.add_field('Content-Type', 'application/json')
-        req.add_field('Authorization', "Bearer #{@auth_token_bearer}") if !@auth_token_bearer.nil?
+        req.add_field('Authorization', "Bearer #{@auth_token_bearer}") unless @auth_token_bearer.nil?
         req.add_field('X-Scope-OrgID', tenant) if tenant
         req.body = Yajl.dump(body)
         req.basic_auth(@username, @password) if @username
@@ -241,7 +240,7 @@ def format_labels(data_labels)
         data_labels = {} if data_labels.nil?
         data_labels = data_labels.merge(@extra_labels)
         # sanitize label values
-        data_labels.each { |k, v| formatted_labels[k] = v.gsub('"', '\\"') if v && v&.is_a?(String) }
+        data_labels.each { |k, v| formatted_labels[k] = v.gsub('"', '\\"') if v.is_a?(String) }
         formatted_labels
       end
 
@@ -270,6 +269,7 @@ def to_nano(time)
         end
       end
 
+      # rubocop:disable Metrics/CyclomaticComplexity, Metrics/PerceivedComplexity
       def record_to_line(record)
         line = ''
         if @drop_single_key && record.keys.length == 1
@@ -282,11 +282,9 @@ def record_to_line(record)
             formatted_labels = []
             record.each do |k, v|
               # Remove non UTF-8 characters by force-encoding the string
-              if v.is_a?(String)
-                v = v.encode('utf-8', invalid: :replace, undef: :replace, replace: '?')
-              end
+              v = v.encode('utf-8', invalid: :replace, undef: :replace, replace: '?') if v.is_a?(String)
               # Escape double quotes and backslashes by prefixing them with a backslash
-              v = v.to_s.gsub(%r{(["\\])}, '\\\\\1')
+              v = v.to_s.gsub(/(["\\])/, '\\\\\1')
               if v.include?(' ') || v.include?('=')
                 formatted_labels.push(%(#{k}="#{v}"))
               else
@@ -298,25 +296,25 @@ def record_to_line(record)
         end
         line
       end
+      # rubocop:enable Metrics/CyclomaticComplexity, Metrics/PerceivedComplexity
 
       # convert a line to loki line with labels
+      # rubocop:disable Metrics/CyclomaticComplexity, Metrics/PerceivedComplexity
       def line_to_loki(record)
         chunk_labels = {}
         line = ''
         if record.is_a?(Hash)
           @record_accessors&.each do |name, accessor|
-            new_key = name.gsub(%r{[.\-\/]}, '_')
+            new_key = name.gsub(%r{[.\-/]}, '_')
             chunk_labels[new_key] = accessor.call(record)
             accessor.delete(record)
           end
 
           if @extract_kubernetes_labels && record.key?('kubernetes')
             kubernetes_labels = record['kubernetes']['labels']
-            if !kubernetes_labels.nil?
-              kubernetes_labels.each_key do |l|
-                new_key = l.gsub(%r{[.\-\/]}, '_')
-                chunk_labels[new_key] = kubernetes_labels[l]
-              end
+            kubernetes_labels&.each_key do |l|
+              new_key = l.gsub(%r{[.\-/]}, '_')
+              chunk_labels[new_key] = kubernetes_labels[l]
             end
           end
 
@@ -345,6 +343,7 @@ def line_to_loki(record)
           labels: chunk_labels
         }
       end
+      # rubocop:enable Metrics/CyclomaticComplexity, Metrics/PerceivedComplexity
 
       # iterate through each chunk and create a loki stream entry
       def chunk_to_loki(chunk)

clients/cmd/fluentd/spec/gems/fluent/plugin/loki_output_spec.rb

@@ -118,12 +118,12 @@
     driver = Fluent::Test::Driver::Output.new(described_class)
     driver.configure(config)
     content = File.readlines('spec/gems/fluent/plugin/data/non_utf8.log')[0]
-    chunk = [Time.at(1_546_270_458), {'message'=>content, 'number': 1.2345, 'stream'=>'stdout'}]
+    chunk = [Time.at(1_546_270_458), { 'message' => content, 'number': 1.2345, 'stream' => 'stdout' }]
     payload = driver.instance.generic_to_loki([chunk])
     expect(payload[0]['stream'].empty?).to eq true
     expect(payload[0]['values'].count).to eq 1
-    expect(payload[0]['values'][0][0]).to eq "1546270458000000000"
-    expect(payload[0]['values'][0][1]).to eq "message=\"? rest of line\" number=1.2345 stream=stdout"
+    expect(payload[0]['values'][0][0]).to eq '1546270458000000000'
+    expect(payload[0]['values'][0][1]).to eq 'message="? rest of line" number=1.2345 stream=stdout'
   end
 
   it 'handle non utf-8 characters from log lines in json format' do
@@ -134,12 +134,14 @@
     driver = Fluent::Test::Driver::Output.new(described_class)
     driver.configure(config)
     content = File.readlines('spec/gems/fluent/plugin/data/non_utf8.log')[0]
-    chunk = [Time.at(1_546_270_458), {'message'=>content, 'number': 1.2345, 'stream'=>'stdout'}]
+    chunk = [Time.at(1_546_270_458), { 'message' => content, 'number': 1.2345, 'stream' => 'stdout' }]
     payload = driver.instance.generic_to_loki([chunk])
     expect(payload[0]['stream'].empty?).to eq true
     expect(payload[0]['values'].count).to eq 1
-    expect(payload[0]['values'][0][0]).to eq "1546270458000000000"
-    expect(payload[0]['values'][0][1]).to eq "{\"message\":\"\xC1 rest of line\",\"number\":1.2345,\"stream\":\"stdout\"}"
+    expect(payload[0]['values'][0][0]).to eq '1546270458000000000'
+    expect(payload[0]['values'][0][1]).to eq(
+      "{\"message\":\"\xC1 rest of line\",\"number\":1.2345,\"stream\":\"stdout\"}"
+    )
   end
 
   it 'formats record hash as key_value' do
@@ -155,7 +157,7 @@
     expect(body[:streams][0]['stream'].empty?).to eq true
     expect(body[:streams][0]['values'].count).to eq 1
     expect(body[:streams][0]['values'][0][0]).to eq '1546270458000000000'
-    expect(body[:streams][0]['values'][0][1]).to eq 'message="' + content[0] + '" stream=stdout'
+    expect(body[:streams][0]['values'][0][1]).to eq "message=\"#{content[0]}\" stream=stdout"
   end
 
   it 'formats record hash as json' do