File: MIGRATING — Documentation for google-cloud-bigquery-data

Migrating to google-cloud-bigquery-data_transfer 1.0

The 1.0 release of the google-cloud-bigquery-data_transfer client is a significant upgrade based on a next-gen code generator, and includes substantial interface changes. Existing code written for earlier versions of this library will likely require updates to use this version. This document describes the changes that have been made, and what you need to do to update your usage.

To summarize:

The library has been broken out into multiple libraries. The new gem google-cloud-bigquery-data_transfer-v1 contains the actual client classes for version V1 of the BigQuery DataTransfer service, and the gem google-cloud-bigquery-data_transfer now simply provides a convenience wrapper. See Library Structure for more info.
The library uses a new configuration mechanism giving you closer control over endpoint address, network timeouts, and retry. See Client Configuration for more info. Furthermore, when creating a client object, you can customize its configuration in a block rather than passing arguments to the constructor. See Creating Clients for more info.
Previously, positional arguments were used to indicate required arguments. Now, all method arguments are keyword arguments, with documentation that specifies whether they are required or optional. Additionally, you can pass a proto request object instead of separate arguments. See Passing Arguments for more info.
Previously, some client classes included class methods for constructing resource paths. These paths are now instance methods on the client objects, and are also available in a separate paths module. See Resource Path Helpers for more info.
Some classes have moved into different namespaces. See Class Namespaces for more info.

Library Structure

Older 0.x releases of the google-cloud-bigquery-data_transfer gem were all-in-one gems that included potentially multiple clients for multiple versions of the BigQuery DataTransfer service. The Google::Cloud::Bigquery::DataTransfer.new factory method would return you an instance of a Google::Cloud::Bigquery::DataTransfer::V1::DataTransferServiceClient object for the V1 version of the service. All these classes were defined in the same gem.

With the 1.0 release, the google-cloud-bigquery-data_transfer gem still provides factory methods for obtaining clients. (The method signatures will have changed. See Creating Clients for details.) However, the actual client classes have been moved into separate gems, one per service version. The Google::Cloud::Bigquery::DataTransfer::V1::DataTransferService::Client class, along with its helpers and data types, is now part of the google-cloud-bigquery-data_transfer-v1 gem. Future versions will similarly be located in additional gems.

For normal usage, you can continue to install the google-cloud-bigquery-data_transfer gem (which will bring in the versioned client gems as dependencies) and continue to use factory methods to create clients. However, you may alternatively choose to install only one of the versioned gems. For example, if you know you will only use V1 of the service, you can install google-cloud-bigquery-data_transfer-v1 by itself, and construct instances of the Google::Cloud::Bigquery::DataTransfer::V1::DataTransferService::Client client class directly.

Client Configuration

In older releases, if you wanted to customize performance parameters or low-level behavior of the client (such as credentials, timeouts, or instrumentation), you would pass a variety of keyword arguments to the client constructor. It was also extremely difficult to customize the default settings.

With the 1.0 release, a configuration interface provides control over these parameters, including defaults for all instances of a client, and settings for each specific client instance. For example, to set default credentials and timeout for all BigQuery DataTransfer V1 clients:

Google::Cloud::Bigquery::DataTransfer::V1::DataTransferService::Client.configure do |config|
  config.credentials = "/path/to/credentials.json"
  config.timeout = 10.0
end

Individual RPCs can also be configured independently. For example, to set the timeout for the get_data_source call:

Google::Cloud::Bigquery::DataTransfer::V1::DataTransferService::Client.configure do |config|
  config.rpcs.get_data_source.timeout = 20.0
end

Defaults for certain configurations can be set for all BigQuery DataTransfer versions and services globally:

Google::Cloud::Bigquery::DataTransfer.configure do |config|
  config.credentials = "/path/to/credentials.json"
  config.timeout = 10.0
end

Finally, you can override the configuration for each client instance. See the next section on Creating Clients for details.

Creating Clients

In older releases, to create a client object, you would use the Google::Cloud::Bigquery::DataTransfer.new class method. Keyword arguments were available to select a service version and to configure parameters such as credentials and timeouts.

With the 1.0 release, use the Google::Cloud::Bigquery::DataTransfer.data_transfer_service class method to create a client object. You may select a service version using the :version keyword argument. (Currently :v1 is the only supported version.) However, other configuration parameters should be set in a configuration block when you create the client.

Old:

client = Google::Cloud::Bigquery::DataTransfer.new credentials: "/path/to/credentials.json"

New:

client = Google::Cloud::Bigquery::DataTransfer.data_transfer_service do |config|
  config.credentials = "/path/to/credentials.json"
end

The configuration block is optional. If you do not provide it, or you do not set some configuration parameters, then the default configuration is used. See Client Configuration.

Passing Arguments

In older releases, required arguments would be passed as positional method arguments, while most optional arguments would be passed as keyword arguments.

With the 1.0 release, all RPC arguments are passed as keyword arguments, regardless of whether they are required or optional. For example:

Old:

client = Google::Cloud::Bigquery::DataTransfer.new

name = "projects/my-project/dataSources/my-source"

# Name is a positional argument
response = client.get_data_source name

New:

client = Google::Cloud::Bigquery::DataTransfer.data_transfer_service

name = "projects/my-project/dataSources/my-source"

# Name is a keyword argument
response = client.get_data_source name: name

In the 1.0 release, it is also possible to pass a request object, either as a hash or as a protocol buffer.

New:

client = Google::Cloud::Bigquery::DataTransfer.data_transfer_service

request = Google::Cloud::Bigquery::DataTransfer::V1::GetDataSourceRequest.new(
  name: "projects/my-project/dataSources/my-source"
)

# Pass a request object as a positional argument:
response = client.get_data_source request

Finally, in older releases, to provide call options, you would pass a Google::Gax::CallOptions object with the :options keyword argument. In the 1.0 release, pass call options using a second set of keyword arguments.

Old:

client = Google::Cloud::Bigquery::DataTransfer.new

name = "projects/my-project/dataSources/my-source"

options = Google::Gax::CallOptions.new timeout: 10.0

response = client.get_data_source name, options: options

New:

client = Google::Cloud::Bigquery::DataTransfer.data_transfer_service

name = "projects/my-project/dataSources/my-source"

# Use a hash to wrap the normal call arguments (or pass a request object), and
# then add further keyword arguments for the call options.
response = client.get_data_source({ name: name }, timeout: 10.0)

Resource Path Helpers

The client library includes helper methods for generating the resource path strings passed to many calls. These helpers have changed in two ways:

In older releases, they are class methods on the client class. In the 1.0 release, they are instance methods on the client. They are also available on a separate paths module that you can include elsewhere for convenience.
In older releases, arguments to a resource path helper are passed as positional arguments. In the 1.0 release, they are passed as named keyword arguments. Some helpers also support different sets of arguments, each set corresponding to a different type of path.

Following is an example involving using a resource path helper.

Old:

client = Google::Cloud::Bigquery::DataTransfer.new

# Call the helper on the client class
name = Google::Cloud::Bigquery::DataTransfer::V1::DataTransferServiceClient.data_source_path(
  "my-project", "my-source"
)

response = client.get_data_source name

New:

client = Google::Cloud::Bigquery::DataTransfer.data_transfer_service

# Call the helper on the client instance, and use keyword arguments
name = client.data_source_path project: "my-project", data_source: "my-source"

response = client.get_data_source name: name

Because IDs are passed as keyword arguments, some closely related paths have been combined. For example, data_source_path and location_data_source_path used to be separate helpers, one that took a location argument and one that did not. In the 1.0 client, use data_source_path for both cases, and either pass or omit the location: keyword argument.

Old:

name1 = Google::Cloud::Bigquery::DataTransfer::V1::DataTransferServiceClient.data_source_path(
  "my-project", "my-source"
)
name2 = Google::Cloud::Bigquery::DataTransfer::V1::DataTransferServiceClient.location_data_source_path(
  "my-project", "my-location", "my-source"
)

New:

client = Google::Cloud::Dlp.dlp_service
name1 = client.data_source_path project: "my-project",
                                data_source: "my-source"
name2 = client.data_source_path project: "my-project",
                                location: "my-location",
                                data_source: "my-source"

Finally, in the 1.0 client, you can also use the paths module as a convenience module.

New:

# Bring the data_source_path method into the current class
include Google::Cloud::Bigquery::DataTransfer::V1::DataTransferService::Paths

def foo
  client = Google::Cloud::Bigquery::DataTransfer.data_transfer_service

  # Call the included helper method
  name = data_source_path project: "my-project", data_source: "my-source"

  response = client.get_data_source name: name

  # Do something with response...
end

Class Namespaces

In older releases, data type classes were generally located under the module Google::Cloud::Bigquery::Datatransfer::V1. (Note the lower-case "t" in "Datatransfer".) In the 1.0 release, these classes have been moved into the same Google::Cloud::Bigquery::DataTransfer::V1 (upper-case "T") module used by the client object, for consistency.

In older releases, the client object was of classes with names like: Google::Cloud::Bigquery::DataTransfer::V1::DataTransferServiceClient. In the 1.0 release, the client object is of a different class: Google::Cloud::Bigquery::DataTransfer::V1::DataTransferService::Client. Note that most users will use the factory methods such as Google::Cloud::Bigquery::DataTransfer.data_transfer_service to create instances of the client object, so you may not need to reference the actual class directly. See Creating Clients.

In older releases, the credentials object was of class Google::Cloud::Bigquery::DataTransfer::V1::Credentials. In the 1.0 release, each service has its own credentials class, e.g. Google::Cloud::Bigquery::DataTransfer::V1::DataTransferService::Credentials. Again, most users will not need to reference this class directly. See Client Configuration.