Use ENV with precedence over YAML configuration (#39)

Author: mullermp

CHANGELOG.md

@@ -1,6 +1,8 @@
 Unreleased Changes
 ------------------
 
+* Issue - `Configuration` now takes environment variables with precedence over YAML configuration.
+
 3.0.0 (2024-10-29)
 ------------------
 

README.md

@@ -37,18 +37,13 @@ gem 'aws-sdk-rails', '~> 4'
 
 A number of options are available to be set in
 `Aws::SessionStore::DynamoDB::Configuration`, which is used throughout the
-application. These options can be set directly by Ruby code, through
-a YAML configuration file, or Environment variables, in order of precedence.
+application. These options can be set directly in Ruby code, in ENV variables,
+or in a YAML configuration file, in order of precedence.
 
 The full set of options along with defaults can be found in the
 [Configuration](https://docs.aws.amazon.com/sdk-for-ruby/aws-sessionstore-dynamodb/api/Aws/SessionStore/DynamoDB/Configuration.html)
 documentation.
 
-### YAML Configuration
-
-You can create a YAML configuration file to set the options. The file must be
-passed into Configuration as the `:config_file` option.
-
 ### Environment Options
 
 All Configuration options can be loaded from the environment except for
@@ -62,6 +57,12 @@ The example below would be a valid way to set the session table name:
 
     export DYNAMO_DB_SESSION_TABLE_NAME='your-table-name'
 
+### YAML Configuration
+
+You can create a YAML configuration file to set the options. The file must be
+passed into Configuration as the `:config_file` option or with the
+`DYNAMO_DB_SESSION_CONFIG_FILE` environment variable.
+
 ## Creating the session table
 
 After installation and configuration, you must create the session table using

lib/aws/session_store/dynamo_db/configuration.rb

@@ -4,7 +4,7 @@
 
 module Aws::SessionStore::DynamoDB
   # This class provides a Configuration object for all DynamoDB session store operations
-  # by pulling configuration options from Runtime, a YAML file, the ENV, and default
+  # by pulling configuration options from Runtime, the ENV, a YAML file, and default
   # settings, in that order.
   #
   # == Environment Variables
@@ -63,7 +63,7 @@ class Configuration
     }.freeze
 
     # Provides configuration object that allows access to options defined
-    # during Runtime, in a YAML file, in the ENV, and by default.
+    # during Runtime, in the ENV, in a YAML file, and by default.
     #
     # @option options [String] :table_name ("sessions") Name of the session table.
     # @option options [String] :table_key ("session_id") The hash key of the session table.
@@ -99,8 +99,9 @@ class Configuration
     # @option options [Aws::DynamoDB::Client] :dynamo_db_client (Aws::DynamoDB::Client.new)
     #   DynamoDB client used to perform database operations inside of the rack application.
     def initialize(options = {})
-      opts = file_options(options).merge(options)
+      opts = options
       opts = env_options.merge(opts)
+      opts = file_options(opts).merge(opts)
       MEMBERS.each_pair do |opt_name, default_value|
         opts[opt_name] = default_value unless opts.key?(opt_name)
       end
@@ -145,13 +146,10 @@ def env_options
     end
 
     def parse_env_value(key)
-      Integer(ENV.fetch(key, nil))
+      val = ENV.fetch(key, nil)
+      Integer(val)
     rescue ArgumentError
-      if ENV[key] == 'true' || ENV[key] == 'false'
-        ENV[key] == 'true'
-      else
-        ENV.fetch(key, nil)
-      end
+      %w[true false].include?(val) ? val == 'true' : val
     end
 
     # @return [Hash] File options.
@@ -168,7 +166,8 @@ def load_from_file(file_path)
       require 'erb'
       require 'yaml'
       opts = YAML.safe_load(ERB.new(File.read(file_path)).result) || {}
-      opts.transform_keys(&:to_sym)
+      unsupported_keys = %i[dynamo_db_client error_handler config_file]
+      opts.transform_keys(&:to_sym).reject { |k, _| unsupported_keys.include?(k) }
     end
 
     def set_attributes(options)

spec/aws/session_store/dynamo_db/configuration_spec.rb

@@ -25,13 +25,13 @@
     }
   end
 
-  def setup_env
+  def setup_env(options)
     options.each do |k, v|
       ENV["DYNAMO_DB_SESSION_#{k.to_s.upcase}"] = v.to_s
     end
   end
 
-  def teardown_env
+  def teardown_env(options)
     options.each_key { |k| ENV.delete("DYNAMO_DB_SESSION_#{k.to_s.upcase}") }
   end
 
@@ -41,44 +41,75 @@ def teardown_env
     allow(Aws::DynamoDB::Client).to receive(:new).and_return(client)
   end
 
-  it 'configures defaults without runtime, YAML or ENV options' do
+  it 'configures defaults without runtime, ENV, or YAML options' do
     cfg = Aws::SessionStore::DynamoDB::Configuration.new
     expect(cfg.to_hash).to include(defaults)
   end
 
-  it 'configures with ENV with precedence over defaults' do
-    setup_env
-    cfg = Aws::SessionStore::DynamoDB::Configuration.new
-    expect(cfg.to_hash).to include(options)
-    teardown_env
+  it 'configures with YAML with precedence over defaults' do
+    Tempfile.create('dynamo_db_session_store.yml') do |f|
+      f << options.transform_keys(&:to_s).to_yaml
+      f.rewind
+      cfg = Aws::SessionStore::DynamoDB::Configuration.new(config_file: f.path)
+      expect(cfg.to_hash).to include(options)
+    end
+  end
+
+  it 'configures with ENV with precedence over YAML' do
+    setup_env(options)
+    Tempfile.create('dynamo_db_session_store.yml') do |f|
+      f << { table_name: 'OldTable', table_key: 'OldKey' }.transform_keys(&:to_s).to_yaml
+      f.rewind
+      cfg = Aws::SessionStore::DynamoDB::Configuration.new(config_file: f.path)
+      expect(cfg.to_hash).to include(options)
+    ensure
+      teardown_env(options)
+    end
+  end
+
+  it 'configures in code with full precedence' do
+    old = { table_name: 'OldTable', table_key: 'OldKey' }
+    setup_env(options.merge(old))
+    Tempfile.create('dynamo_db_session_store.yml') do |f|
+      f << old.transform_keys(&:to_s).to_yaml
+      f.rewind
+      cfg = Aws::SessionStore::DynamoDB::Configuration.new(options.merge(config_file: f.path))
+      expect(cfg.to_hash).to include(options)
+    ensure
+      teardown_env(options.merge(old))
+    end
   end
 
-  it 'configs with YAML with precedence over ENV' do
-    setup_env
+  it 'allows for config file to be configured with ENV' do
     Tempfile.create('dynamo_db_session_store.yml') do |f|
       f << options.transform_keys(&:to_s).to_yaml
       f.rewind
       ENV['DYNAMO_DB_SESSION_CONFIG_FILE'] = f.path
       cfg = Aws::SessionStore::DynamoDB::Configuration.new
-      ENV.delete('DYNAMO_DB_SESSION_CONFIG_FILE')
       expect(cfg.to_hash).to include(options)
+    ensure
+      ENV.delete('DYNAMO_DB_SESSION_CONFIG_FILE')
     end
-    teardown_env
   end
 
-  it 'configures with runtime options with full precedence' do
-    setup_env
+  it 'ignores unsupported keys in ENV' do
+    ENV['DYNAMO_DB_SESSION_DYNAMO_DB_CLIENT'] = 'Client'
+    ENV['DYNAMO_DB_SESSION_ERROR_HANDLER'] = 'Handler'
+    cfg = Aws::SessionStore::DynamoDB::Configuration.new
+    expect(cfg.to_hash).to include(defaults)
+  ensure
+    ENV.delete('DYNAMO_DB_SESSION_DYNAMO_DB_CLIENT')
+    ENV.delete('DYNAMO_DB_SESSION_ERROR_HANDLER')
+  end
+
+  it 'ignores unsupported keys in YAML' do
     Tempfile.create('dynamo_db_session_store.yml') do |f|
-      f << { table_name: 'OldTable', table_key: 'OldKey' }.transform_keys(&:to_s).to_yaml
+      options = { dynamo_db_client: 'Client', error_handler: 'Handler', config_file: 'File' }
+      f << options.transform_keys(&:to_s).to_yaml
       f.rewind
-      cfg = Aws::SessionStore::DynamoDB::Configuration.new(
-        options.merge(
-          config_file: f.path
-        )
-      )
-      expect(cfg.to_hash).to include(options)
+      cfg = Aws::SessionStore::DynamoDB::Configuration.new(config_file: f.path)
+      expect(cfg.to_hash).to include(defaults.merge(config_file: f.path))
     end
-    teardown_env
   end
 
   it 'raises an exception when wrong path for file' do

spec/aws/session_store/dynamo_db/garbage_collection_spec.rb

@@ -4,17 +4,14 @@
 
 describe Aws::SessionStore::DynamoDB::GarbageCollection do
   def items(min, max)
-    items = []
-    (min..max).each do |i|
-      items << { 'session_id' => { s: i.to_s } }
+    (min..max).map do |i|
+      { 'session_id' => { s: i.to_s } }
     end
-    items
   end
 
   def format_scan_result
-    items = []
-    (31..49).each do |i|
-      items << { 'session_id' => { s: i.to_s } }
+    items = (31..49).map do |i|
+      { 'session_id' => { s: i.to_s } }
     end
 
     items.each_with_object([]) do |item, rqst_array|