google pubsub ruby publish example

require "base64"
require "google/api_client"

key_file = "./google.p12"
key_secret = 'notasecret'
key = Google::APIClient::KeyUtils.load_from_pkcs12(key_file, key_secret)
service_account_email = '@developer.gserviceaccount.com'

auth_params = {
  token_credential_uri: "https://accounts.google.com/o/oauth2/token",
  audience: "https://accounts.google.com/o/oauth2/token",
  scope: "https://www.googleapis.com/auth/pubsub",
  issuer: service_account_email,
  signing_key: key
}
client = Google::APIClient.new(
  application_name: "pubsubtest", application_version: "v1",
  authorization: Signet::OAuth2::Client.new(auth_params)
)

client.authorization.fetch_access_token!

pubsub_api = client.discovered_api("pubsub", "v1beta2")

r = client.execute(
  api_method: pubsub_api.projects.topics.publish,
  parameters: {
    topic: "projects/xxx/topics/topic1"
  },
  body_object: { messages: [{ data: Base64.strict_encode64("hi simon, how is it hanging?") }] }
)

if r.error?
  p r.inspect
  raise "fail to publish"
end