FFM-12088 Retry on HTTP status code 0 / add optional timeout to wait_for_initialization (#44)

* FFM-12088 Retry on http code 0

* FFM-12088 Return http code if it is there

* FFM-12088 Bump version

* FFM-12088 Add wait_for_init timeout + sdk code

* FFM-12088 Update docs

* FFM-12088 Update log

* FFM-12088 Change timeout param name

* FFM-12088 Remove commented out code

* FFM-12088 Bump minor version

Author: erdirowlands

docs/further_reading.md

@@ -24,6 +24,50 @@ client.init(apiKey, ConfigBuilder
 | enableStream    | analytics_enabled(false)                           | Enable streaming mode.                                                                                                                           | true                                 |
 | enableAnalytics | stream_enabled(true)                               | Enable analytics.  Metrics data is posted every 60s                                                                                              | true                                 |
 
+## Client Initialization Options
+The Harness Feature Flags SDK for Ruby provides flexible initialization strategies to accommodate various application requirements. You can choose between an asynchronous (non-blocking) or synchronous (blocking) approach to initialize the SDK.
+
+### Asynchronous (Non-Blocking) Initialization
+The SDK can be initialized asynchronously without blocking the main thread or requiring a callback. In this case, defaults will be served until the SDK completes the initialization process.
+
+```ruby
+client = CfClient.instance
+client.init(api_key, config)
+
+# Will serve default until the SDK completes initialization
+result = client.bool_variation("bool_flag", target, false)
+```
+
+### Synchronous (Blocking) Initialization
+
+In cases where it's critical to ensure the SDK is initialized before evaluating flags, the SDK offers a synchronous initialization method. This approach blocks the current thread until the SDK is fully initialized or the optional specified timeout (in milliseconds) period elapses.
+
+The synchronous method is useful for environments where feature flag decisions are needed before continuing, such as during application startup.
+
+You can use the `wait_for_initialization` method, optionally providing a timeout in milliseconds to prevent waiting indefinitely in case of unrecoverable isues, e.g. incorrect API key used.
+
+**Usage with a timeout**
+
+```ruby
+client = CfClient.instance
+client.init(api_key, config)
+
+client.wait_for_initialization
+
+result = client.bool_variation("bool_flag", target, false)
+```
+
+**Usage without a timeout**
+
+```ruby
+client = CfClient.instance
+client.init(api_key, config)
+
+client.wait_for_initialization(timeout_ms: 3000)
+
+result = client.bool_variation("bool_flag", target, false)
+```
+
 ## Logging Configuration
 You can provide your own logger to the SDK i.e. using the moneta logger we can do this
 

lib/ff/ruby/server/sdk/api/auth_service.rb

@@ -89,8 +89,9 @@ def should_retry_http_code(code)
     # 503 service unavailable
     # 504 gateway timeout
     #  -1 OpenAPI error (timeout etc)
+    # 0 Un-categorised typhoeus error
     case code
-    when 408,425,429,500,502,503,504,-1
+    when 408,425,429,500,502,503,504,-1, 0
       return true
     else
       return false

lib/ff/ruby/server/sdk/api/cf_client.rb

@@ -50,11 +50,9 @@ def init(api_key = nil, config = nil, connector = nil)
     end
   end
 
-  def wait_for_initialization
-
+  def wait_for_initialization(timeout_ms: nil)
     if @client != nil
-
-      @client.wait_for_initialization
+      @client.wait_for_initialization(timeout: timeout_ms)
     end
   end
 

lib/ff/ruby/server/sdk/api/inner_client.rb

@@ -231,28 +231,41 @@ def on_processor_ready(processor)
     @initialized = true
   end
 
-  def wait_for_initialization
-
+  def wait_for_initialization(timeout: nil)
     synchronize do
+      SdkCodes::info_sdk_waiting_to_initialize(@config.logger, timeout)
 
-      @config.logger.debug "Waiting for initialization to finish"
+      start_time = Time.now
 
       until @initialized
+        # Check if a timeout is specified and has been exceeded
+        if timeout && (Time.now - start_time) > (timeout / 1000.0)
+          @config.logger.warn "The SDK has timed out waiting to initialize with supplied timeout #{timeout} ms"
+          handle_initialization_failure
+        end
 
         sleep(1)
       end
 
       if @failure
-
         raise "Initialization failed"
       end
 
       @config.logger.debug "Waiting for initialization has completed"
     end
   end
 
+
   protected
 
+  def handle_initialization_failure
+    @auth_service.close
+    @poll_processor.stop
+    @update_processor.stop
+    @metrics_processor.stop
+    on_auth_failed
+  end
+
   def setup
 
     @repository = StorageRepository.new(@config.cache, @repository_callback, @config.store, @config.logger)

lib/ff/ruby/server/sdk/common/sdk_codes.rb

@@ -14,6 +14,17 @@ def self.info_sdk_init_ok(logger)
     logger.info SdkCodes.sdk_err_msg(1000)
   end
 
+  def self.info_sdk_waiting_to_initialize(logger, timeout)
+    if timeout
+      message = "with timeout: #{timeout} ms"
+    else
+
+      message = "with no timeout"
+
+    end
+    logger.info SdkCodes.sdk_err_msg(1003, message)
+  end
+
   def self.info_sdk_auth_ok(logger)
     logger.info SdkCodes.sdk_err_msg(2000)
   end
@@ -76,6 +87,7 @@ def self.warn_bucket_by_attr_not_found(logger, attr_name, new_value)
       1000 => "The SDK has successfully initialized",
       1001 => "The SDK has failed to initialize due to the following authentication error:",
       1002 => "The SDK has failed to initialize due to a missing or empty API key",
+      1003 => "The SDK is waiting for initialzation to complete",
       # SDK_AUTH_2xxx
       2000 => "Authenticated ok",
       2001 => "Authentication failed with a non-recoverable error - defaults will be served",

lib/ff/ruby/server/sdk/connector/harness_connector.rb

@@ -46,6 +46,11 @@ def authenticate
         # determine if a timeout has occurred. This is fixed in 6.3.0 but requires Ruby version to be increased to 2.7
         # https://github.com/OpenAPITools/openapi-generator/releases/tag/v6.3.0
         @config.logger.warn "OpenapiClient::ApiError [\n\n#{e}\n]"
+
+        if e.code
+          return e.code
+        end
+
         return -1
       end
 

lib/ff/ruby/server/sdk/version.rb

@@ -5,7 +5,7 @@ module Ruby
     module Server
       module Sdk
 
-        VERSION = "1.3.2"
+        VERSION = "1.4.0"
       end
     end
   end

scripts/sdk_specs.sh

@@ -1,4 +1,4 @@
 #!/bin/bash
 
 export ff_ruby_sdk="ff-ruby-server-sdk"
-export ff_ruby_sdk_version="1.3.2"
+export ff_ruby_sdk_version="1.4.0"