Server Source code Package

GCP Cloud Functions

Google Cloud Functions source for walkerOS. Lightweight runtime adapter with plug-and-play assignment to a Cloud Functions handler, support for the shared event envelope including batches, a GET tracking pixel, and configurable CORS. The @walkeros/server-source-gcp package also ships sourcePubSubPull and sourcePubSubPush for ingesting from Pub/Sub topics; this page covers the Cloud Functions handler only.

Where this fits

The GCP Cloud Functions source is a server source in the walkerOS flow:

It receives events via HTTP and forwards them to your destinations.

Installation

npm install @walkeros/server-source-gcp @google-cloud/functions-framework

Integrated

import { sourceCloudFunction } from '@walkeros/server-source-gcp';
import { startFlow } from '@walkeros/collector';
import { http } from '@google-cloud/functions-framework';

const { sources } = await startFlow({
  sources: {
    gcp: {
      code: sourceCloudFunction,
      config: {
        settings: { cors: true },
      },
    },
  },
  destinations: {
    // Your destinations
  },
});

// Plug-and-play: source.push IS the Cloud Function handler
http('walkerHandler', sources.gcp.push);

Bundled

Add to your flow.json sources:

"sources": {
  "gcp": {
    "package": "@walkeros/server-source-gcp",
    "config": {
      "settings": {
        "cors": true,
      }
    }
  }
}

Server sources require platform-specific handlers. For containerized deployments, see Docker.

See bundled mode setup | CLI reference

Configuration

This source uses the standard source config wrapper (consent, data, env, id, ...). For the shared fields see source configuration. Package-specific fields live under config.settings and are listed below.

Settings

Property	Type	Description	More
cors	boolean | object	CORS configuration: false = disabled, true = allow all origins, object = custom configuration
maxBatchSize	integer	Maximum number of events accepted in a single batch request
enablePixelTracking	boolean	Serve a tracking pixel for GET requests
timeout	integer	Request timeout in milliseconds (max: 540000 for GCP)

Mapping

This package does not define custom rule-level settings. For the standard rule fields (consent, condition, data, batch, name, policy) see mapping.

Examples

POST with provenance

A POST body carrying a source map is forwarded in full, so release and trace provenance survive the crossing.

Event

{
  "method": "POST",
  "body": {
    "name": "page view",
    "data": {
      "title": "Home"
    },
    "source": {
      "release": {
        "web": "r1"
      }
    }
  },
  "headers": {
    "content-type": "application/json"
  }
}

Out

elb({
  "name": "page view",
  "data": {
    "title": "Home"
  },
  "source": {
    "release": {
      "web": "r1"
    }
  }
})

Order POST

A Cloud Function HTTP POST carrying an order payload becomes a walker order complete event.

Event

{
  "method": "POST",
  "body": {
    "name": "order complete",
    "data": {
      "id": "ORD-700",
      "total": 99.99,
      "currency": "EUR"
    }
  },
  "headers": {
    "content-type": "application/json"
  }
}

Out

elb({
  "name": "order complete",
  "data": {
    "id": "ORD-700",
    "total": 99.99,
    "currency": "EUR"
  }
})

POST event

A GCP Cloud Function HTTP POST with a JSON body becomes a single walker elb event.

Event

{
  "method": "POST",
  "body": {
    "name": "page view",
    "data": {
      "title": "Home",
      "url": "https://example.com/"
    }
  },
  "headers": {
    "content-type": "application/json"
  }
}

Out

elb({
  "name": "page view",
  "data": {
    "title": "Home",
    "url": "https://example.com/"
  }
})

Request format

The event name field is name. Every other field of the body is forwarded to the collector as-is, so source (carrying release and trace provenance) rides through instead of being dropped.

Single event

{
  "name": "page view",
  "data": {
    "title": "Home Page",
    "path": "/"
  }
}

Batch events

Send several events in one request with the shared envelope. See Event Envelope for the accepted forms, the maxBatchSize cap and the 207 partial-failure response.

{
  "batch": [
    { "name": "page view", "data": { "title": "Page 1" } },
    { "name": "button click", "data": { "id": "btn1" } }
  ]
}

Responses

Status	Meaning
200	Event processed
400	Rejected client input: the pipeline declared the event invalid. The body echoes the validation message, for example Event name is required
500	The pipeline failed to process a valid event, or an unexpected server fault

Invalid input is counted on collector.status.sources.<id>.rejected rather than inflating status.failed, and is logged at warn with the reason instead of as an error with a stack trace.

Ingest metadata

Extract request metadata and forward it through the pipeline.

config.ingest must use the map operator. Keys are output field names; values are direct field paths on the request scope (no req. prefix). A bare object like { ip: 'ip' } is silently inert: without the map operator the source passes the whole request through and no field is extracted.

const { sources } = await startFlow({
  sources: {
    gcp: {
      code: sourceCloudFunction,
      config: {
        settings: { cors: true },
        ingest: {
          map: {
            ip: { key: 'ip' },
            ua: { key: 'headers.user-agent' },
            origin: { key: 'headers.origin' },
          },
        },
      },
    },
  },
});

Available ingest paths

Path	Description
ip	Client IP address
headers.*	HTTP headers (user-agent, origin, etc.)
method	HTTP method
hostname	Request hostname

Pub/Sub

The same @walkeros/server-source-gcp package also exports sourcePubSubPull (streaming pull subscriber) and sourcePubSubPush (HTTP webhook handler) for ingesting events from a Pub/Sub topic. See the Pub/Sub source page for full settings, lifecycle, decoders, OIDC verification, and setup reference.