How to trigger Slack notifications as an Action

This guide will help you trigger Slack notifications as an ActionA Python class with a run method that takes a Validation Result and does something with it. It will allow you to send a Slack message including information about a Validation ResultGenerated when data is Validated against an Expectation or Expectation Suite., including whether or not the ValidationThe act of applying an Expectation Suite to a Batch. succeeded.

Great Expectations is able to use a Slack webhook or Slack app to send notifications.

Prerequisites

For webhook

Prerequisites: This how-to guide assumes you have:

• Completed the Getting Started Tutorial
• Have a working installation of Great Expectations
• Configured a Slack app with the Webhook function enabled (See Additional Resources below for more information on setting up a new Slack app).
• Obtained the Webhook address for your Slack app.
• Identified the Slack channel that messages will be sent to.

For Slack app

Prerequisites: This how-to guide assumes you have:

• Completed the Getting Started Tutorial
• Have a working installation of Great Expectations
• Configure a Slack app with a Bot Token (See Additional Resources below for more information on setting up a new Slack app)
• Obtain the Bot Token for your Slack app.
• Identified the Slack channel that the messages will be sent to.

Steps

1. Edit your configuration variables to include the Slack webhook

Open uncommitted/config_variables.yml file and add validation_notification_slack_webhook variable by adding the following line:

validation_notification_slack_webhook: [address to web hook]

2. Edit your validation_operators configuration to include the send_slack_notification_on_validation_result Action

Open great_expectations.yml and add send_slack_notification_on_validation_result Action to validation_operators. Make sure the following section exists in the great_expectations.yml file.

Webhook config

validation_operators:
    action_list_operator:
        # To learn how to configure sending Slack notifications during evaluation
        # (and other customizations), read: https://docs.greatexpectations.io/docs/guides/validation/validation_actions/how_to_trigger_slack_notifications_as_a_validation_action/#webhook-config
        class_name: ActionListValidationOperator
        action_list:
        #--------------------------------
        # here is what you will be adding
        #--------------------------------
        - name: send_slack_notification_on_validation_result # name can be set to any value
          action:
            class_name: SlackNotificationAction
            # put the actual webhook URL in the uncommitted/config_variables.yml file
            slack_webhook: ${validation_notification_slack_webhook}
            notify_on: all # possible values: "all", "failure", "success"
            notify_with: # optional list containing the DataDocs sites to include in the notification. Defaults to including links to all configured sites.
            renderer:
              module_name: great_expectations.render.renderer.slack_renderer
              class_name: SlackRenderer

Slack bot config

validation_operators:
    action_list_operator:
        # To learn how to configure sending Slack notifications during evaluation
        # (and other customizations), read: https://docs.greatexpectations.io/docs/guides/validation/validation_actions/how_to_trigger_slack_notifications_as_a_validation_action/#slack-bot-config
        class_name: ActionListValidationOperator
        action_list:
        #--------------------------------
        # here is what you will be adding
        #--------------------------------
        - name: send_slack_notification_on_validation_result # name can be set to any value
          action:
            class_name: SlackNotificationAction
            # put the actual bot token in the uncommitted/config_variables.yml file
            slack_token: {bot_token}
            slack_channel: <channel-name>
            notify_on: all # possible values: "all", "failure", "success"
            notify_with: # optional list containing the DataDocs sites to include in the notification. Defaults to including links to all configured sites.
            renderer:
              module_name: great_expectations.render.renderer.slack_renderer
              class_name: SlackRenderer

4. Test your Slack notifications

Run your action_list_operator, to Validate a BatchA selection of records from a Data Asset. of data and receive Slack notification on the success or failure of the Expectation Suite'sA collection of verifiable assertions about data. Validation.

context.run_validation_operator('action_list_operator', assets_to_validate=batch, run_name="slack_test")

If successful, you should receive a Slack message that looks like this:

Additional notes

• If your great_expectations.yml contains multiple configurations for Data DocsHuman readable documentation generated from Great Expectations metadata detailing Expectations, Validation Results, etc. sites, all of them will be included in the Slack notification by default. If you would like to be more specific, you can configure the notify_with variable in your great_expectations.yml.
• The following example will configure the Slack message to include links Data Docs at local_site and s3_site.

    # Example data_docs_sites configuration
    data_docs_sites:
      local_site:
        class_name: SiteBuilder
        show_how_to_buttons: true
        store_backend:
          class_name: TupleFilesystemStoreBackend
          base_directory: uncommitted/data_docs/local_site/
        site_index_builder:
          class_name: DefaultSiteIndexBuilder
      s3_site:  # this is a user-selected name - you may select your own
        class_name: SiteBuilder
        store_backend:
          class_name: TupleS3StoreBackend
          bucket: data-docs.my_org  # UPDATE the bucket name here to match the bucket you configured above.
        site_index_builder:
          class_name: DefaultSiteIndexBuilder
          show_cta_footer: true

    validation_operators:
        action_list_operator:
        ...
        - name: send_slack_notification_on_validation_result # name can be set to any value
              action:
                class_name: SlackNotificationAction
                # put the actual webhook URL in the uncommitted/config_variables.yml file
                slack_webhook: ${validation_notification_slack_webhook}
                notify_on: all # possible values: "all", "failure", "success"
                #--------------------------------
                # This is what was configured
                #--------------------------------
                notify_with:
                  - local_site
                  - s3_site
                renderer:
                  module_name: great_expectations.render.renderer.slack_renderer
                  class_name: SlackRenderer

Additional resources

• Instructions on how to set up a Slack app with webhook can be found in the documentation for the Slack API