Route Firebase Realtime Database events to GKE

Console

1. In the Google Cloud console, on the project selector page, select or create a Google Cloud project.

   Go to project selector

2. Enable the Eventarc, Eventarc Publishing, Google Kubernetes Engine, and Resource Manager APIs.

   Enable the APIs

3. If applicable, enable the API related to the direct events. For example, for Firebase Realtime Database events, enable the Firebase Realtime Database API.

4. If you don't already have one, create a user-managed service account, then grant it the roles and permissions necessary so that Eventarc can manage events for your target service.

   1. In the Google Cloud console, go to the Create service account page.

      Go to Create service account

   2. Select your project.

   3. In the Service account name field, enter a name. The Google Cloud console fills in the Service account ID field based on this name.

      In the Service account description field, enter a description. For example, Service account for event trigger.

   4. Click Create and continue.

   5. To provide appropriate access, in the Select a role list, select the required Identity and Access Management (IAM) roles to grant to your service account. For more information, see Roles and permissions for GKE targets.

      For additional roles, click add Add another role and add each additional role.

   6. Click Continue.

   7. To finish creating the account, click Done.

gcloud

1. In the Google Cloud console, activate Cloud Shell.

   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.

2. Enable the Eventarc, Eventarc Publishing, Google Kubernetes Engine, and Resource Manager APIs.

   gcloud services enable eventarc.googleapis.com \
       eventarcpublishing.googleapis.com \
       container.googleapis.com \
       cloudresourcemanager.googleapis.com

3. If applicable, enable the API related to the direct events. For example, for Firebase Realtime Database events, enable firebasedatabase.googleapis.com.

4. If you don't already have one, create a user-managed service account, then grant it the roles and permissions necessary so that Eventarc can manage events for your target GKE destination.

   1. Create the service account:

      gcloud iam service-accounts create SERVICE_ACCOUNT_NAME

      Replace SERVICE_ACCOUNT_NAME with the name of the service account. It must be between 6 and 30 characters, and can contain lowercase alphanumeric characters and dashes. After you create a service account, you cannot change its name.

   2. Grant the required Identity and Access Management (IAM) roles or permissions. For more information, see Roles and permissions for GKE targets.

Console

1. In the Google Cloud console, go to the Eventarc Triggers page.

   Go to Triggers

2. Click add_box Create trigger.
3. Type a Trigger name.

   This is the ID of the trigger and it must start with a letter. It can contain up to 63 lowercase letters, numbers, or hyphens.

4. For the Trigger type, select Google sources.
5. In the Event provider list, select Firebase Realtime Database.

   Note that the event provider name used in the associated Google Cloud documentation might not have a prefix of Cloud or Google Cloud. For example, on the console, Memorystore for Redis is referred to as Google Cloud Memorystore for Redis.

6. In the Event type list, from the Direct events, select an event type.
7. In the Event data content type list, select the encoding of the event payload.

   For direct events from Firebase Realtime Database, this must be application/json.

8. In the Region list, select the same region as the Google Cloud service that is generating events.

   For more information, see Eventarc locations.

9. In the Attribute 1 field, the instance resource ID acts as an event filter. Select an operator for this filter:
   • Equal
   • Path pattern

     For more information, see Understand path patterns.

10. In the Attribute value 1 field, enter the name of the database instance to receive events from. Depending on the operator that you chose in the previous step, the attribute value should be the exact name or a path pattern format.
11. For the ref attribute, select the Path pattern operator.
12. In the Attribute value 2 field, enter the database instance path to receive events from if data is created, updated, or deleted in that path or any child path.
13. Select the Service account that will invoke your service or workflow.

    Or, you can create a new service account.

    This specifies the Identity and Access Management (IAM) service account email associated with the trigger and to which you previously granted specific roles required by Eventarc.

14. In the Event destination list, select Kubernetes Engine.
15. Select a service.
    

    This is the name of the service that receives the events for the trigger. The service must be in the same project as the trigger and will receive events as HTTP POST requests sent to its root URL path (/), whenever the event is generated.

16. Optionally, you can specify the Service URL path to send the incoming request to.

    This is the relative path on the destination service to which the events for the trigger should be sent. For example: /, /route, route, route/subroute.

17. Click Create.

After a trigger is created, the event source filters cannot be modified. Instead, create a new trigger and delete the old one. For more information, see Manage triggers.

gcloud

You can create a trigger by running a gcloud eventarc triggers create command along with required and optional flags.

gcloud eventarc triggers create TRIGGER \
    --location=LOCATION \
    --destination-gke-cluster=DESTINATION_GKE_CLUSTER \
    --destination-gke-location=DESTINATION_GKE_LOCATION \
    --destination-gke-namespace=DESTINATION_GKE_NAMESPACE \
    --destination-gke-service=DESTINATION_GKE_SERVICE \
    --destination-gke-path=DESTINATION_GKE_PATH \
    --event-filters="type=EVENT_FILTER_TYPE" \
    --event-filters="instance=INSTANCE" \
    --event-filters-path-pattern="ref=REF" \
    --service-account=SERVICE_ACCOUNT_NAME@PROJECT_ID.iam.gserviceaccount.com"

Replace the following:

• TRIGGER: the ID of the trigger or a fully qualified identifier

• LOCATION: the location of the Eventarc trigger. Alternatively, you can set the eventarc/location property; for example gcloud config set eventarc/location us-central1.

  Firebase Realtime Database triggers for Eventarc are only available in certain locations and the trigger must be in the same location as the Firebase Realtime Database instance. For more information, see Eventarc locations and Realtime Database locations.

• DESTINATION_GKE_CLUSTER: the name of the GKE cluster in which the target GKE service that receives events is running.
• DESTINATION_GKE_LOCATION: (optional) the Compute Engine region of the GKE cluster in which the destination GKE service is running in. If not specified, it is assumed that the cluster is a regional cluster and is in the same region as the trigger.
• DESTINATION_GKE_NAMESPACE: (optional) the namespace in which the destination GKE service is running. If not specified, the default namespace is used.
• DESTINATION_GKE_SERVICE: the name of the GKE service that receives the events for the trigger. The service can be in any of the GKE supported locations and does not need to be in the same location as the trigger. However, the service must be in the same project as the trigger and will receive events as HTTP POST requests sent to its root URL path (/), whenever the event is generated.
• DESTINATION_GKE_PATH: (optional) the relative path you specify on the destination GKE service to which the events for the trigger should be sent. For example: /, /route, route, route/subroute.

• EVENT_FILTER_TYPE: the identifier of the Firebase Realtime Database event and can be one of the following:

  • google.firebase.database.ref.v1.created: event is sent when data is created in the database
  • google.firebase.database.ref.v1.updated: event is sent when data is updated in the database
  • google.firebase.database.ref.v1.deleted: event is sent when data is deleted in the database
  • google.firebase.database.ref.v1.written: event is sent when data is created, updated, or deleted in the database

• INSTANCE: a single database instance and the operator can be one of the following:

  • Equal; for example, --event-filters="instance=INSTANCE"
  • Path pattern; for example, --event-filters-path-pattern="instance=INSTANCE". For more information, see Understand path patterns.

• REF: the path within the database instance for which you want to receive events from when data is created, updated, or deleted in that path, or any of its children.

• SERVICE_ACCOUNT_NAME: the name of your user-managed service account.
• PROJECT_ID: your Google Cloud project ID.

Notes:

• For direct events from Firebase Realtime Database, the encoding of the event payload is application/json.
• These flags are required:
  • --event-filters="type=EVENT_FILTER_TYPE"
  • --event-filters="instance=INSTANCE" or --event-filters-path-pattern="instance=INSTANCE"
  • --event-filters-path-pattern="ref=REF"
  • After a trigger is created, the event filter type can't be changed. For a different event type, you must create a new trigger and delete the old one.
  • The --service-account flag is used to specify the Identity and Access Management (IAM) service account email associated with the trigger.

Example:

gcloud eventarc triggers create helloworld-trigger \
    --location=us-central1 \
    --destination-gke-cluster=gke-events-cluster \
    --destination-gke-location=us-central1-a \
    --destination-gke-namespace=default \
    --destination-gke-service=helloworld-events \
    --destination-gke-path=/ \
    --event-filters="type=google.firebase.database.ref.v1.created" \
    --event-filters="instance=test-instance" \
    --event-filters-path-pattern="ref=users/*" \
    --service-account=${SERVICE_ACCOUNT_NAME}@${PROJECT_ID}.iam.gserviceaccount.com

This command creates a trigger called helloworld-trigger for the event identified as google.firebase.database.ref.v1.created and for the users/* path within the database instance identified as test-instance.

Terraform

You can create a trigger for a GKE destination using Terraform. For details, see Create a trigger using Terraform.

Console

1. In the Google Cloud console, go to the Eventarc Triggers page.

   Go to Triggers

   This page lists your triggers in all locations, and includes details such as names, regions, event providers, destinations, and more.

2. To filter your triggers:

   1. Click filter_list Filter or the Filter triggers field.
   2. In the Properties list, select an option to filter the triggers by.

   You can select a single property or use the logical operator OR to add more properties.

3. To sort your triggers, beside any supported column heading, click arrow_upward Sort.

gcloud

Run the following command to list your triggers:

gcloud eventarc triggers list --location=-

This command lists your triggers in all locations, and includes details such as names, types, destinations, and statuses.