Class: ConfigurationService::Base

Inherits:
Object
  • Object
show all
Defined in:
lib/configuration_service/base.rb

Overview

The configuration service API

The service provides authorized publication and consumption of identified configuration data with metadata.

It is recommended that consumers use a Factory to create and configure the service.

Instance Method Summary collapse

Constructor Details

#initialize(identifier, token, provider) ⇒ Base

Creates a new API instance for the service provider

The identifier is a string that uniquely identifies some configuration data and associated metadata. It might be the name of a service or service component. It might include an environment label (e.g. production, staging, etc.) For example:

  • billing.acme.com

  • billing-web1.acme.com

  • billing/production/web1

The token is a string that authorizes the client to access the configuration data and associated metadata. Interpretation of the token is provider-dependent; it is opaque to the API and client.

The provider is a configured service provider instance.



33
34
35
36
37
 
# File 'lib/configuration_service/base.rb', line 33

def initialize(identifier, token, provider)
  @identifier = identifier
  @token = token
  @provider = provider
end

Instance Method Details

#publish_configuration(data, metadata = {}) ⇒ Object

Publishes configuration data and optional metadata

The data and the metadata (if specified) must be dictionaries (responding to #to_hash or #to_h). The provider receives a a Configuration object, whose metadata is decorated with the following keys:

  • “timestamp” - the current UTC time in ISO8601 format

  • “revision” - a UUID for this publication

Returns a Configuration object or raises an Error on failure. When a Configuration object is returned, its metadata is the decorated copy, allowing access to additional metadata added by the API or the provider.



66
67
68
69
70
71
72
73
 
# File 'lib/configuration_service/base.rb', line 66

def publish_configuration(data, metadata = {})
  dictionary?(data) or raise ConfigurationService::Error, "data must be a dictionary"
  dictionary?(metadata) or raise ConfigurationService::Error, "metadata must be a dictionary"

  metadata = decorate(metadata)
  configuration = Configuration.new(@identifier, data, metadata)
  @provider.publish_configuration(configuration, @token)
end

#request_configuration ⇒ Object

Requests the configuration data and metadata for the identifier

Delegates the request to the provider.

Returns a Configuration object or raises an Error on failure. Raises ConfigurationNotFoundError if no matching configuration was found.



48
49
50
51
 
# File 'lib/configuration_service/base.rb', line 48

def request_configuration
  @provider.request_configuration(@identifier, @token) or
    raise ConfigurationNotFoundError, "configuration not found for identifier: #{@identifier}"
end