Configuring Google Pub/Sub Operations

To use the Google Pub/Sub connector, add the <googlepubsub.init> element in your configuration before any other Google Pub/Sub operation. 

Google Pub/Sub uses the OAuth 2.0 protocol for authentication and authorization. All requests to the Google Cloud Pub/Sub API must be authorized by an authenticated user. For information on how to obtain authentication and authorization user credentials, see Obtaining user credentials.

<googlepubsub.init>
    <apiUrl>{$ctx:apiUrl}</apiUrl>
    <apiVersion>{$ctx:apiVersion}</apiVersion>
    <accessToken>{$ctx:accessToken}</accessToken>
    <clientId>{$ctx:clientId}</clientId>
    <clientSecret>{$ctx:clientSecret}</clientSecret>
    <refreshToken>{$ctx:refreshToken}</refreshToken>
    <blocking>{$ctx:blocking}</blocking>
</googlepubsub.init>

Properties 

• apiUrl: The application URL of Google Pub/Sub.
• apiVersion: The version of the Google Pub/Sub API.
• accessToken: The access token that grants access to the Google Pub/Sub API on behalf of a user.
• clientId: The client id provided by the Google developer console.
• clientSecret: The client secret provided by the Google developer console.
• refreshToken: The refresh token provided by the Google developer console, which can be used to obtain new access tokens.
• blocking: This is a boolean type property. Set this to true if you want the connector to perform blocking invocations to Google Pub/Sub.

Obtaining user credentials

• Follow the steps below to obtain a client ID and client secret:

  1. Go to https://console.developers.google.com/projectselector/apis/credentials, and sign in to your Google account.

  2. If you do not already have a project, create a new project, click Create credentials, and then select OAuth client ID.

  3. Next, select Web Application, and create a client.

  4. Provide https://developers.google.com/oauthplayground as the redirect URL under Authorized redirect URIs, and then click Create. This displays the client ID and client secret.

  5. Make a note of the client ID and client secret that is displayed, and then click OK.

  6. Click Library on the left navigation pane, and select Google Cloud Pub/Sub API under the Big data or Networking category.

  7. Click Enable. This enables the Google Cloud Pub/Sub API.

• Follow the steps below to obtain an access token and refresh token:

  1. Go to https://developers.google.com/oauthplayground, click the gear icon on the top right corner of the screen, and select Use your own OAuth credentials.
  2. Specify the client ID and client secret that you obtained in step 3 above, and click Close.
  3. Under Step 1 on the screen, select Google Cloud Pub/Sub API from the list of APIs, and then select all the scopes that are listed under Google Cloud Pub/Sub API.
  4. Click Authorize APIs. This requests for permission to access your profile details.
  5. Click ALLOW.
  6. In Step 2 on the screen, click Exchange authorization code for tokens to generate and view the access token and refresh token.

Now that you have connected to Google pub sub, use the information in the following topics to perform various operations with the connector:

• Working with Project Subscriptions in Google Pub/Sub
• Working with Project Topics in Google Pub/Sub