Cloud Spanner API - Class Google::Cloud::Spanner::Policy (v2.18.0)

Reference documentation and code samples for the Cloud Spanner API class Google::Cloud::Spanner::Policy.

Policy

Represents a Cloud IAM Policy for the Spanner service.

A common pattern for updating a resource's metadata, such as its Policy, is to read the current data from the service, update the data locally, and then send the modified data for writing. This pattern may result in a conflict if two or more processes attempt the sequence simultaneously. IAM solves this problem with the #etag property, which is used to verify whether the policy has changed since the last request. When you make a request to with an etag value, Cloud IAM compares the etag value in the request with the existing etag value associated with the policy. It writes the policy only if the etag values match.

When you update a policy, first read the policy (and its current etag) from the service, then modify the policy locally, and then write the modified policy to the service. See Instance#policy and Instance#policy= and Database#policy and Database#policy=.

Inherits

  • Object

Example

require "google/cloud/spanner"

spanner = Google::Cloud::Spanner.new
instance = spanner.instance "my-instance"

policy = instance.policy do |p|
  p.remove "roles/owner", "user:owner@example.com"
  p.add "roles/owner", "user:newowner@example.com"
  p.roles["roles/viewer"] = ["allUsers"]
end

Methods

#add

def add(role_name, member)

Convenience method for adding a member to a binding on this policy. See Understanding Roles for a listing of primitive and curated roles. See Binding for a listing of values and patterns for members.

Parameters
  • role_name (String) — A Cloud IAM role, such as "roles/spanner.admin".
  • member (String) — A Cloud IAM identity, such as "user:owner@example.com".
Example 
require "google/cloud/spanner"

spanner = Google::Cloud::Spanner.new
instance = spanner.instance "my-instance"

policy = instance.policy do |p|
  p.add "roles/owner", "user:newowner@example.com"
end

#etag

def etag() -> String

Used to verify whether the policy has changed since the last request. The policy will be written only if the etag values match.

Returns
  • (String) — the current value of etag

#etag=

def etag=(value) -> String

Used to verify whether the policy has changed since the last request. The policy will be written only if the etag values match.

Parameter
  • value (String) — the newly set value
Returns
  • (String) — the newly set value

#remove

def remove(role_name, member)

Convenience method for removing a member from a binding on this policy. See Understanding Roles for a listing of primitive and curated roles. See Binding for a listing of values and patterns for members.

Parameters
  • role_name (String) — A Cloud IAM role, such as "roles/spanner.admin".
  • member (String) — A Cloud IAM identity, such as "user:owner@example.com".
Example 
require "google/cloud/spanner"

spanner = Google::Cloud::Spanner.new
instance = spanner.instance "my-instance"

policy = instance.policy do |p|
  p.remove "roles/owner", "user:owner@example.com"
end

#role

def role(role_name) -> Array<String>

Convenience method returning the array of members bound to a role in this policy, or an empty array if no value is present for the role in #roles. See Understanding Roles for a listing of primitive and curated roles. See Binding for a listing of values and patterns for members.

Returns
  • (Array<String>) — The members strings, or an empty array.
Example 
require "google/cloud/spanner"

spanner = Google::Cloud::Spanner.new
instance = spanner.instance "my-instance"

policy = instance.policy do |p|
  p.role("roles/viewer") << "user:viewer@example.com"
end

#roles

def roles() -> Hash{String => Array<String>}

The bindings that associate roles with an array of members. See Understanding Roles for a listing of primitive and curated roles. See Binding for a listing of values and patterns for members.

Returns
  • (Hash{String => Array<String>}) — the current value of roles

#roles=

def roles=(value) -> Hash{String => Array<String>}

The bindings that associate roles with an array of members. See Understanding Roles for a listing of primitive and curated roles. See Binding for a listing of values and patterns for members.

Parameter
  • value (Hash{String => Array<String>}) — the newly set value
Returns
  • (Hash{String => Array<String>}) — the newly set value