Class: DevCycle::ConfigManager

Inherits:
Object
  • Object
show all
Extended by:
T::Sig
Defined in:
lib/devcycle-ruby-server-sdk/localbucketing/config_manager.rb

Instance Method Summary collapse

Constructor Details

#initialize(sdkKey, local_bucketing, wait_for_init) ⇒ ConfigManager

Returns a new instance of ConfigManager.



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# File 'lib/devcycle-ruby-server-sdk/localbucketing/config_manager.rb', line 18

def initialize(sdkKey, local_bucketing, wait_for_init)
  @first_load = true
  @config_version = "v2"
  @local_bucketing = local_bucketing
  @sdkKey = sdkKey
  @sse_url = ""
  @sse_polling = false
  @config_e_tag = ""
  @config_last_modified = ""
  @logger = local_bucketing.options.logger
  @enable_sse = local_bucketing.options.enable_beta_realtime_updates
  @polling_enabled = true
  @sse_active = false
  @max_config_retries = 2
  @config_poller = Concurrent::TimerTask.new({
                                               execution_interval: @local_bucketing.options.config_polling_interval_ms.fdiv(1000)
                                             }) do |_|
    fetch_config
  end

  t = Thread.new { initialize_config }
  t.join if wait_for_init
end

Instance Method Details

#close ⇒ Object 



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# File 'lib/devcycle-ruby-server-sdk/localbucketing/config_manager.rb', line 186

def close
  @config_poller.shutdown if @config_poller.running?
  nil
end

#fetch_config(min_last_modified: -1)) ⇒ Object 



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# File 'lib/devcycle-ruby-server-sdk/localbucketing/config_manager.rb', line 53

def fetch_config(min_last_modified: -1)
  return unless @polling_enabled || (@sse_active && @enable_sse)

  req = Typhoeus::Request.new(
    get_config_url,
    headers: {
      Accept: "application/json",
    })

  begin
    # Blind parse the lastmodified string to check if it's a valid date.
    # This short circuits the rest of the checks if it's not set
    if @config_last_modified != ""
      if min_last_modified != -1
        stored_date = Date.parse(@config_last_modified)
        parsed_sse_ts = Time.at(min_last_modified)
        if parsed_sse_ts.utc > stored_date.utc
          req.options[:headers]["If-Modified-Since"] = parsed_sse_ts.utc.httpdate
        else
          req.options[:headers]["If-Modified-Since"] = @config_last_modified
        end
      else
        req.options[:headers]["If-Modified-Since"] = @config_last_modified
      end
    end
  rescue
  end

  if @config_e_tag != ""
    req.options[:headers]['If-None-Match'] = @config_e_tag
  end

  @max_config_retries.times do
    @logger.debug("Requesting new config from #{get_config_url}, current etag: #{@config_e_tag}, last modified: #{@config_last_modified}")
    resp = req.run
    @logger.debug("Config request complete, status: #{resp.code}")
    case resp.code
    when 304
      @logger.debug("Config not modified, using cache, etag: #{@config_e_tag}, last modified: #{@config_last_modified}")
      break
    when 200
      @logger.debug("New config received, etag: #{resp.headers['Etag']} LastModified:#{resp.headers['Last-Modified']}")
      begin
        if @config_last_modified == ""
          set_config(resp.body, resp.headers['Etag'], resp.headers['Last-Modified'])
          return
        end

        lm_timestamp = Time.rfc2822(resp.headers['Last-Modified'])
        current_lm = Time.rfc2822(@config_last_modified)
        if lm_timestamp == "" && @config_last_modified == "" || (current_lm.utc < lm_timestamp.utc)
          set_config(resp.body, resp.headers['Etag'], resp.headers['Last-Modified'])
        else
          @logger.warn("Config last-modified was an older date than currently stored config.")
        end
      rescue
        @logger.warn("Failed to parse last modified header, setting config anyway.")
        set_config(resp.body, resp.headers['Etag'], resp.headers['Last-Modified'])
      end
      break
    when 403
      stop_polling
      stop_sse
      @logger.error("Failed to download DevCycle config; Invalid SDK Key.")
      break
    when 404
      stop_polling
      stop_sse
      @logger.error("Failed to download DevCycle config; Config not found.")
      break
    when 500...599
      @logger.error("Failed to download DevCycle config. Status: #{resp.code}")
    else
      @logger.error("Unexpected response from DevCycle CDN")
      @logger.error("Response code: #{resp.code}")
      @logger.error("Response body: #{resp.body}")
      break
    end
  end
  nil
end

#get_config_url ⇒ Object 



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# File 'lib/devcycle-ruby-server-sdk/localbucketing/config_manager.rb', line 156

def get_config_url
  configBasePath = @local_bucketing.options.config_cdn_uri
  "#{configBasePath}/config/#{@config_version}/server/#{@sdkKey}.json"
end

#handle_sse(event_data) ⇒ Object 



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# File 'lib/devcycle-ruby-server-sdk/localbucketing/config_manager.rb', line 207

def handle_sse(event_data)
  unless @sse_polling
    stop_polling
    start_polling(true)
  end
  if event_data["data"] == nil
    return
  end
  @logger.debug("SSE: Message received: #{event_data["data"]}")
  parsed_event_data = JSON.parse(event_data["data"])

  last_modified = parsed_event_data["lastModified"]
  event_type = parsed_event_data["type"]

  if event_type == "refetchConfig" || event_type == nil
    @logger.debug("SSE: Re-fetching new config with TS: #{last_modified}")
    fetch_config(min_last_modified: last_modified / 1000)
  end
end

#init_sse(path) ⇒ Object 



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# File 'lib/devcycle-ruby-server-sdk/localbucketing/config_manager.rb', line 191

def init_sse(path)
  return unless @enable_sse
  @logger.debug("Initializing SSE with url: #{path}")
  @sse_active = true
  @sse_client = SSE::Client.new(path) do |client|
    client.on_event do |event|

      parsed_json = JSON.parse(event.data)
      handle_sse(parsed_json)
    end
    client.on_error do |error|
      @logger.debug("SSE Error: #{error.message}")
    end
  end
end

#initialize_config ⇒ Object 



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# File 'lib/devcycle-ruby-server-sdk/localbucketing/config_manager.rb', line 42

def initialize_config
  begin
    fetch_config
    start_polling(false)
  rescue => e
    @logger.error("DevCycle: Error Initializing Config: #{e.message}")
  ensure
    @local_bucketing.initialized = true
  end
end

#set_config(config, etag, lastmodified) ⇒ Object 



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# File 'lib/devcycle-ruby-server-sdk/localbucketing/config_manager.rb', line 135

def set_config(config, etag, lastmodified)
  if !JSON.parse(config).is_a?(Hash)
    raise("Invalid JSON body parsed from Config Response")
  end
  parsed_config = JSON.parse(config)

  if parsed_config['sse'] != nil
    raw_url = "#{parsed_config['sse']['hostname']}#{parsed_config['sse']['path']}"
    if @sse_url != raw_url && raw_url != ""
      stop_sse
      @sse_url = raw_url
      init_sse(@sse_url)
    end
  end
  @local_bucketing.store_config(config)
  @config_e_tag = etag
  @config_last_modified = lastmodified
  @local_bucketing.has_config = true
  @logger.debug("New config stored, etag: #{@config_e_tag}, last modified: #{@config_last_modified}")
end

#start_polling(sse) ⇒ Object 



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# File 'lib/devcycle-ruby-server-sdk/localbucketing/config_manager.rb', line 161

def start_polling(sse)
  if sse
    @config_poller.shutdown if @config_poller.running?
    @config_poller = Concurrent::TimerTask.new({ execution_interval: 60 * 10 }) do |_|
      fetch_config
    end
    @sse_polling = sse
  end
  @polling_enabled = true
  @config_poller.execute if @polling_enabled && (!@sse_active || sse)
end

#stop_polling ⇒ Object 



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# File 'lib/devcycle-ruby-server-sdk/localbucketing/config_manager.rb', line 173

def stop_polling()
  @polling_enabled = false
  @config_poller.shutdown if @config_poller.running?
end

#stop_sse ⇒ Object 



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# File 'lib/devcycle-ruby-server-sdk/localbucketing/config_manager.rb', line 178

def stop_sse
  return unless @enable_sse
  @sse_active = false
  @sse_polling = false
  @sse_client.close if @sse_client
  start_polling(@sse_polling)
end