Class: Aws::SessionStore::DynamoDB::Configuration

Inherits:
Object
  • Object
show all
Defined in:
lib/aws/session_store/dynamo_db/configuration.rb

Overview

This class provides a Configuration object for all DynamoDB session store operations by pulling configuration options from Runtime, the ENV, a YAML file, and default settings, in that order.

# Environment Variables The Configuration object can load default values from your environment. All configuration keys are supported except for ‘:dynamo_db_client` and `:error_handler`. The keys take the form of AWS_DYNAMO_DB_SESSION_<KEY_NAME>. Example:

export AWS_DYNAMO_DB_SESSION_TABLE_NAME='Sessions'
export AWS_DYNAMO_DB_SESSION_TABLE_KEY='id'

# Locking Strategy By default, locking is disabled for session store access. To enable locking, set the ‘:enable_locking` option to true. The locking strategy is pessimistic, meaning that only one read can be made on a session at once. While the session is being read by the process with the lock, other processes may try to obtain a lock on the same session but will be blocked. See the initializer for how to configure the pessimistic locking strategy to your needs.

# Handling Errors There are two configurable options for error handling: ‘:raise_errors` and `:error_handler`.

If you would like to use the Default Error Handler, you can decide to set ‘:raise_errors` to true or false depending on whether you want all errors, regardless of class, to be raised up the stack and essentially throw a 500.

If you decide to use your own Error Handler, you must implement the ‘BaseErrorHandler` class and pass it into the `:error_handler` option. # DynamoDB Specific Options You may configure the table name and table hash key value of your session table with the `:table_name` and `:table_key` options. You may also configure performance options for your table with the `:consistent_read`, `:read_capacity`, `:write_capacity`. For more information about these configurations see CreateTable method for Amazon DynamoDB.

See Also:

  • Interface for Error Handling for DynamoDB Session Store.

Constant Summary collapse

MEMBERS =

This constant is part of a private API. You should avoid using this constant if possible, as it may be removed or be changed in the future. 

{
  table_name: 'sessions',
  table_key: 'session_id',
  secret_key: nil,
  consistent_read: true,
  read_capacity: 10,
  write_capacity: 5,
  raise_errors: false,
  error_handler: nil,
  max_age: nil,
  max_stale: nil,
  enable_locking: false,
  lock_expiry_time: 500,
  lock_retry_delay: 500,
  lock_max_wait_time: 1,
  config_file: nil,
  dynamo_db_client: nil
}.freeze

Instance Method Summary collapse

Constructor Details

#initialize(options = {}) ⇒ Configuration

Provides configuration object that allows access to options defined during Runtime, in the ENV, in a YAML file, and by default.

Parameters:

  • options (Hash) (defaults to: {}) —

    a customizable set of options

Options Hash (options):

  • :table_name (String) — default: "sessions" —

    Name of the session table.

  • :table_key (String) — default: "session_id" —

    The hash key of the session table.

  • :secret_key (String) —

    Secret key for HMAC encryption.

  • :consistent_read (Boolean) — default: true —

    If true, a strongly consistent read is used. If false, an eventually consistent read is used. @see docs.aws.amazon.com/amazondynamodb/latest/developerguide/HowItWorks.ReadConsistency.html

  • :read_capacity (Integer) — default: 10 —

    The maximum number of strongly consistent reads consumed per second before DynamoDB raises a ThrottlingException. @see docs.aws.amazon.com/amazondynamodb/latest/developerguide/read-write-operations.html

  • :write_capacity (Integer) — default: 5 —

    The maximum number of writes consumed per second before DynamoDB returns a ThrottlingException. @see docs.aws.amazon.com/amazondynamodb/latest/developerguide/read-write-operations.html

  • :raise_errors (Boolean) — default: false —

    If true, all errors are raised up the stack when default ErrorHandler. If false, Only specified errors are raised up the stack when the default ErrorHandler is used.

  • :error_handler (#handle_error) — default: Errors::DefaultHandler —

    An error handling object that handles all exceptions thrown during execution of the rack application.

  • :max_age (Integer) — default: nil —

    Maximum number of seconds earlier from the current time that a session was created.

  • :max_stale (Integer) — default: nil —

    Maximum number of seconds before current time that session was last accessed.

  • :enable_locking (Integer) — default: false —

    If true, a pessimistic locking strategy will be used for all session accesses.

  • :lock_expiry_time (Integer) — default: 500 —

    Time in milliseconds after which the lock expires on session.

  • :lock_retry_delay (Integer) — default: 500 —

    Time in milliseconds to wait before retrying to obtain lock once an attempt to obtain the lock has been made and has failed.

  • :lock_max_wait_time (Integer) — default: 500 —

    Maximum time in seconds to wait to acquire the lock before giving up.

  • :config_file (String, Pathname) —

    Path to a YAML file that contains configuration options.

  • :dynamo_db_client (Aws::DynamoDB::Client) — default: Aws::DynamoDB::Client.new —

    DynamoDB client used to perform database operations inside of the rack application.



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# File 'lib/aws/session_store/dynamo_db/configuration.rb', line 101

def initialize(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
  opts = opts.merge(dynamo_db_client: default_dynamo_db_client(opts))
  opts = opts.merge(error_handler: default_error_handler(opts)) unless opts[:error_handler]

  set_attributes(opts)
end

Instance Method Details

#to_hash ⇒ Hash

Returns The merged configuration hash.

Returns:

  • (Hash) —

    The merged configuration hash.



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# File 'lib/aws/session_store/dynamo_db/configuration.rb', line 119

def to_hash
  MEMBERS.each_with_object({}) do |(key, _), hash|
    hash[key] = send(key)
  end
end