This document shows you how to validate schemas for Pub/Sub topics.
You can validate that messages adhere to a certain schema, before or after you create a schema resource. This step ensures that the messages you intend to send through a topic associated with a schema actually match before applying the schema.
Before you begin
- Understand how Pub/Sub schemas work .
- Create a schema .
Required roles and permissions
To get the permissions that
you need to validate schema messages and manage them,
ask your administrator to grant you the Pub/Sub Editor
( roles/pubsub.editor
)
IAM role on your project.
For more information about granting roles, see Manage access to projects, folders, and organizations
.
This predefined role contains the permissions required to validate schema messages and manage them. To see the exact permissions that are required, expand the Required permissionssection:
Required permissions
The following permissions are required to validate schema messages and manage them:
- Create schema:
pubsub.schemas.create - Attach schema to topic:
pubsub.schemas.attach - Commit a schema revision:
pubsub.schemas.commit - Delete a schema or a schema revision:
pubsub.schemas.delete - Get a schema or schema revisions:
pubsub.schemas.get - List schemas:
pubsub.schemas.list - List schema revisions:
pubsub.schemas.listRevisions - Rollback a schema:
pubsub.schemas.rollback - Validate a message:
pubsub.schemas.validate - Get the IAM policy for a schema:
pubsub.schemas.getIamPolicy - Configure the IAM policy
for a schema:
pubsub.schemas.setIamPolicy
You might also be able to get these permissions with custom roles or other predefined roles .
You can grant roles and permissions to principals such as users, groups, domains, or service accounts. You can create a schema in one project and attach it to a topic located in a different project. Ensure that you have the required permissions for each project.
Validate a message for a schema
Console
-
In the Google Cloud console, go to the Pub/Sub schemaspage.
The list of schemas is displayed.
-
Click the Schema IDof an existing schema.
The Schema detailspage for the schema opens.
-
In the Revisionssection, click the revision for which you want to validate a message.
-
In the Detailssection, click Test message.
-
In the Test messagewindow, select a type of Message encoding.
-
In the Messagebody, enter a test message.
-
Click Test.
gcloud
-
In the Google Cloud console, activate Cloud Shell.
At the bottom of the Google Cloud console, a Cloud Shell session starts and displays a command-line prompt. Cloud Shell is a shell environment with the Google Cloud CLI already installed and with values already set for your current project. It can take a few seconds for the session to initialize.
- To validate a message against a schema use the gcloud pubsub schemas validate-message
command.
gcloud pubsub schemas validate-message --message= MESSAGE \ --message-encoding= MESSAGE_ENCODING \ (--schema-name= SCHEMA_NAME | \ --type= TYPE \ (--definition= DEFINITION | \ --definition-file= DEFINITION_FILE ))
Replace the following:
-
MESSAGE : message to validate against the schema
-
MESSAGE_ENCODING : encoding of the message. Specify one of the following values:
binaryorjson. -
SCHEMA_NAME : name or full path of an existing schema.
-
TYPE : type of inline schema. Specify one of the following values:
avroorprotocol-buffer. -
DEFINITION : inline schema definition.
-
DEFINITION_FILE : file containing the schema definition.
-
