module Google::Cloud::PubSub

# Google Cloud Pub/Sub

Google Cloud Pub/Sub is designed to provide reliable, many-to-many, asynchronous messaging between applications. Publisher applications can send messages to a “topic” and other applications can subscribe to that topic to receive the messages. By decoupling senders and receivers, Google Cloud Pub/Sub allows developers to communicate between independently written applications.

See {file:OVERVIEW.md Google Cloud Pub/Sub Overview}.

Constants

VERSION

Public Class Methods

configure() { |configure.pubsub| ... } click to toggle source

Configure the Google Cloud PubSub library.

The following PubSub configuration parameters are supported:

  • `project_id` - (String) Identifier for a PubSub project. (The parameter `project` is considered deprecated, but may also be used.)

  • `credentials` - (String, Hash, Google::Auth::Credentials) The path to the keyfile as a String, the contents of the keyfile as a Hash, or a Google::Auth::Credentials object. (See {PubSub::Credentials}) (The parameter `keyfile` is considered deprecated, but may also be used.)

  • `scope` - (String, Array<String>) The OAuth 2.0 scopes controlling the set of resources and operations that the connection can access.

  • `retries` - (Integer) Number of times to retry requests on server error.

  • `timeout` - (Integer) Default timeout to use in requests.

  • `endpoint` - (String) Override of the endpoint host name, or `nil` to use the default endpoint.

  • `emulator_host` - (String) Host name of the emulator. Defaults to `ENV`

  • `on_error` - (Proc) A Proc to be run when an error is encountered on a background thread. The Proc must take the error object as the single argument. (See {Subscriber.on_error}.)

@return [Google::Cloud::Config] The configuration object the

Google::Cloud::PubSub library uses.
# File lib/google/cloud/pubsub.rb, line 138
def self.configure
  yield Google::Cloud.configure.pubsub if block_given?

  Google::Cloud.configure.pubsub
end
default_credentials(scope: nil) click to toggle source

@private Default credentials.

# File lib/google/cloud/pubsub.rb, line 154
def self.default_credentials scope: nil
  Google::Cloud.configure.pubsub.credentials ||
    Google::Cloud.configure.credentials ||
    PubSub::Credentials.default(scope: scope)
end
default_project_id() click to toggle source

@private Default project.

# File lib/google/cloud/pubsub.rb, line 146
def self.default_project_id
  Google::Cloud.configure.pubsub.project_id ||
    Google::Cloud.configure.project_id ||
    Google::Cloud.env.project_id
end
new(project_id: nil, credentials: nil, scope: nil, timeout: nil, endpoint: nil, emulator_host: nil, project: nil, keyfile: nil) click to toggle source

Creates a new object for connecting to the Pub/Sub service. Each call creates a new connection.

For more information on connecting to Google Cloud see the {file:AUTHENTICATION.md Authentication Guide}.

@param [String] project_id Project identifier for the Pub/Sub service

you are connecting to. If not present, the default project for the
credentials is used.

@param [String, Hash, Google::Auth::Credentials] credentials The path to

the keyfile as a String, the contents of the keyfile as a Hash, or a
Google::Auth::Credentials object. (See {PubSub::Credentials})

@param [String, Array<String>] scope The OAuth 2.0 scopes controlling

the set of resources and operations that the connection can access.
See [Using OAuth 2.0 to Access Google
APIs](https://developers.google.com/identity/protocols/OAuth2).

The default scope is:

* `https://www.googleapis.com/auth/pubsub`

@param [Integer] timeout Default timeout to use in requests. Optional. @param [String] endpoint Override of the endpoint host name. Optional.

If the param is nil, uses the default endpoint.

@param [String] emulator_host Pub/Sub emulator host. Optional.

If the param is nil, uses the value of the `emulator_host` config.

@param [String] project Alias for the `project_id` argument. Deprecated. @param [String] keyfile Alias for the `credentials` argument.

Deprecated.

@return [Google::Cloud::PubSub::Project]

@example

require "google/cloud/pubsub"

pubsub = Google::Cloud::PubSub.new

topic = pubsub.topic "my-topic"
topic.publish "task completed"
# File lib/google/cloud/pubsub.rb, line 76
def self.new project_id: nil,
             credentials: nil,
             scope: nil,
             timeout: nil,
             endpoint: nil,
             emulator_host: nil,
             project: nil,
             keyfile: nil
  project_id    ||= (project || default_project_id)
  scope         ||= configure.scope
  timeout       ||= configure.timeout
  endpoint      ||= configure.endpoint
  emulator_host ||= configure.emulator_host

  if emulator_host
    project_id = project_id.to_s # Always cast to a string
    raise ArgumentError, "project_id is missing" if project_id.empty?

    service = PubSub::Service.new project_id, :this_channel_is_insecure, host: emulator_host, timeout: timeout
    return PubSub::Project.new service
  end

  credentials ||= (keyfile || default_credentials(scope: scope))
  unless credentials.is_a? Google::Auth::Credentials
    credentials = PubSub::Credentials.new credentials, scope: scope
  end

  project_id ||= credentials.project_id if credentials.respond_to? :project_id
  project_id = project_id.to_s # Always cast to a string
  raise ArgumentError, "project_id is missing" if project_id.empty?

  service = PubSub::Service.new project_id, credentials, host: endpoint, timeout: timeout
  PubSub::Project.new service
end