remote_settings: delete the code for config dumping/loading

Some of our users complain that our airbrake-ruby notifier tries to dump the
remote config that we pull from S3 to the gem directory. The OS user that is
running the code may not have write access to that directory and therefore
writing the remote config will fail.

There's no good universal location to keep persistent remote config, so it's
easier just to delete the config.

lib/airbrake-ruby/remote_settings.rb

@@ -8,22 +8,11 @@ module Airbrake
   #     config.error_notifications = data.error_notifications?
   #   end
   #
-  # When {#poll} is called, it will try to load remote settings from disk, so
-  # that it doesn't wait on the result from the API call.
-  #
-  # When {#stop_polling} is called, the current config will be dumped to disk.
-  #
   # @since 5.0.0
   # @api private
   class RemoteSettings
     include Airbrake::Loggable
 
-    # @return [String] the path to the persistent config
-    CONFIG_DUMP_PATH = File.join(
-      File.expand_path(__dir__),
-      '../../config/config.json',
-    ).freeze
-
     # @return [Hash{Symbol=>String}] metadata to be attached to every GET
     #   request
     QUERY_PARAMS = URI.encode_www_form(
@@ -54,18 +43,11 @@ def initialize(project_id, host, &block)
       @poll = nil
     end
 
-    # Polls remote config of the given project in background. Loads local config
-    # first (if exists).
+    # Polls remote config of the given project in background.
     #
     # @return [self]
     def poll
       @poll ||= Thread.new do
-        begin
-          load_config
-        rescue StandardError => ex
-          logger.error("#{LOG_LABEL} config loading failed: #{ex}")
-        end
-
         @block.call(@data)
 
         loop do
@@ -77,17 +59,11 @@ def poll
       self
     end
 
-    # Stops the background poller thread. Dumps current config to disk.
+    # Stops the background poller thread.
     #
     # @return [void]
     def stop_polling
       @poll.kill if @poll
-
-      begin
-        dump_config
-      rescue StandardError => ex
-        logger.error("#{LOG_LABEL} config dumping failed: #{ex}")
-      end
     end
 
     private
@@ -124,22 +100,5 @@ def build_config_uri
       uri.query = QUERY_PARAMS
       uri
     end
-
-    def load_config
-      config_dir = File.dirname(CONFIG_DUMP_PATH)
-      Dir.mkdir(config_dir) unless File.directory?(config_dir)
-
-      return unless File.exist?(CONFIG_DUMP_PATH)
-
-      config = File.read(CONFIG_DUMP_PATH)
-      @data.merge!(JSON.parse(config))
-    end
-
-    def dump_config
-      config_dir = File.dirname(CONFIG_DUMP_PATH)
-      Dir.mkdir(config_dir) unless File.directory?(config_dir)
-
-      File.write(CONFIG_DUMP_PATH, JSON.dump(@data.to_h))
-    end
   end
 end

spec/remote_settings_spec.rb

@@ -22,42 +22,19 @@
     }
   end
 
-  let(:config_path) { described_class::CONFIG_DUMP_PATH }
-  let(:config_dir) { File.dirname(config_path) }
-
   let!(:stub) do
     stub_request(:get, Regexp.new(endpoint))
       .to_return(status: 200, body: body.to_json)
   end
 
-  before do
-    # Do not create config dumps on disk.
-    allow(Dir).to receive(:mkdir).with(config_dir)
-    allow(File).to receive(:write).with(config_path, anything)
-  end
-
   describe ".poll" do
     describe "config loading" do
       let(:settings_data) { described_class::SettingsData.new(project_id, body) }
 
       before do
-        allow(File).to receive(:exist?).with(config_path).and_return(true)
-        allow(File).to receive(:read).with(config_path).and_return(body.to_json)
-
         allow(described_class::SettingsData).to receive(:new).and_return(settings_data)
       end
 
-      it "loads the config from disk" do
-        expect(File).to receive(:read).with(config_path)
-        expect(settings_data).to receive(:merge!).with(body).twice
-
-        remote_settings = described_class.poll(project_id, host) {}
-        sleep(0.2)
-        remote_settings.stop_polling
-
-        expect(stub).to have_been_requested.once
-      end
-
       it "yields the config to the block twice" do
         block = proc {}
         expect(block).to receive(:call).twice
@@ -68,21 +45,6 @@
 
         expect(stub).to have_been_requested.once
       end
-
-      context "when config loading fails" do
-        it "logs an error" do
-          expect(File).to receive(:read).and_raise(StandardError)
-          expect(Airbrake::Loggable.instance).to receive(:error).with(
-            '**Airbrake: config loading failed: StandardError',
-          )
-
-          remote_settings = described_class.poll(project_id, host) {}
-          sleep(0.2)
-          remote_settings.stop_polling
-
-          expect(stub).to have_been_requested.once
-        end
-      end
     end
 
     context "when no errors are raised" do
@@ -199,32 +161,4 @@
       end
     end
   end
-
-  describe "#stop_polling" do
-    it "dumps config data to disk" do
-      expect(Dir).to receive(:mkdir).with(config_dir)
-      expect(File).to receive(:write).with(config_path, body.to_json)
-
-      remote_settings = described_class.poll(project_id, host) {}
-      sleep(0.2)
-      remote_settings.stop_polling
-
-      expect(stub).to have_been_requested.once
-    end
-
-    context "when config dumping fails" do
-      it "logs an error" do
-        expect(File).to receive(:write).and_raise(StandardError)
-        expect(Airbrake::Loggable.instance).to receive(:error).with(
-          '**Airbrake: config dumping failed: StandardError',
-        )
-
-        remote_settings = described_class.poll(project_id, host) {}
-        sleep(0.2)
-        remote_settings.stop_polling
-
-        expect(stub).to have_been_requested.once
-      end
-    end
-  end
 end