Cloud Functions OpenTelemetry Tracing

This guide shows you how to send traces from a Google Cloud Function to SigNoz using OpenTelemetry. The default path uses zero-code auto instrumentation through environment variables. If you need deeper control, use the optional code-based setup section.

Prerequisites

A Google Cloud project with billing enabled.
Cloud Functions API enabled in your project.
A 2nd gen Cloud Function using Node.js 20.
A SigNoz Cloud account or self-hosted SigNoz instance.

Send traces to SigNoz

Step 1. Create an HTTP Cloud Function

In Google Cloud Console:

Open Cloud Functions and click Create function.
Select 2nd gen.
Set Runtime to Node.js 20.
Set Trigger to HTTP.

You will add runtime environment variables and code in the next steps.

Step 2. Configure OpenTelemetry environment variables.

In Runtime, build, connections and security settings -> Runtime environment variables, add:

OTEL_TRACES_EXPORTER=otlp
OTEL_EXPORTER_OTLP_PROTOCOL=http/json
OTEL_EXPORTER_OTLP_TRACES_ENDPOINT=https://ingest.<region>.signoz.cloud/v1/traces
OTEL_EXPORTER_OTLP_HEADERS=signoz-ingestion-key=<your-ingestion-key>
OTEL_SERVICE_NAME=<your-service-name>
OTEL_PROPAGATORS=tracecontext
OTEL_RESOURCE_ATTRIBUTES=deployment.environment.name=production

Verify these values:

<region>: Your SigNoz Cloud region.
<your-ingestion-key>: Your SigNoz ingestion key.
<your-service-name>: Name that will appear in SigNoz Services (for example, gcp-fn-orders).
OTEL_RESOURCE_ATTRIBUTES: Comma-separated resource attributes. Keep deployment.environment.name=production or set your environment value.

Step 3. Install the required packages

Run this in your Cloud Function project directory:

npm install --save \
  @google-cloud/functions-framework \
  @opentelemetry/api \
  @opentelemetry/auto-instrumentations-node \
  @opentelemetry/exporter-trace-otlp-http \
  @opentelemetry/sdk-node

This creates or updates package.json and package-lock.json with the dependencies used by the examples in this guide.

Step 4. Update `index.js`

Add the register import at the top of your entry file. Your handler code stays unchanged -- no manual tracing calls are needed.

index.js

'use strict';

require('@opentelemetry/auto-instrumentations-node/register');

const functions = require('@google-cloud/functions-framework');

functions.http('entryPoint', (req, res) => {
  res.status(200).json({
    ok: true,
    message: req.query.message || 'Hello from Cloud Functions',
  });
});

What this does:

The register import loads OpenTelemetry auto-instrumentation before your function handler code runs.
Common incoming/outgoing HTTP operations are traced automatically.

Step 5. Deploy and invoke the function

Deploy the function.
Copy the HTTPS trigger URL after deployment.
Invoke it once:

curl "https://<your-cloud-function-url>?message=hello-signoz"

Validate

After invoking the function, verify traces in SigNoz:

Open SigNoz and go to Services.
Find the service name you set in OTEL_SERVICE_NAME.
Open Traces and filter by service.name=<your-service-name>.
Open a trace and confirm request spans from your function are present.

Code-Based Setup (Optional)

Step 1. Install OpenTelemetry packages

npm install --save \
  @google-cloud/functions-framework \
  @google-cloud/opentelemetry-cloud-trace-propagator \
  @opentelemetry/core \
  @opentelemetry/exporter-trace-otlp-http \
  @opentelemetry/resource-detector-gcp \
  @opentelemetry/resources \
  @opentelemetry/sdk-node \
  @opentelemetry/semantic-conventions

Step 2. Create `tracing.js`

Create a new file named tracing.js in your function source.

tracing.js

'use strict';

const { NodeSDK } = require('@opentelemetry/sdk-node');
const {
  CompositePropagator,
  W3CBaggagePropagator,
  W3CTraceContextPropagator,
} = require('@opentelemetry/core');
const { CloudPropagator } = require('@google-cloud/opentelemetry-cloud-trace-propagator');
const { gcpDetector } = require('@opentelemetry/resource-detector-gcp');
const { OTLPTraceExporter } = require('@opentelemetry/exporter-trace-otlp-http');
const { resourceFromAttributes } = require('@opentelemetry/resources');
const {
  ATTR_SERVICE_NAME,
  ATTR_SERVICE_NAMESPACE,
  ATTR_SERVICE_VERSION,
} = require('@opentelemetry/semantic-conventions');
const { ATTR_DEPLOYMENT_ENVIRONMENT_NAME } = require('@opentelemetry/semantic-conventions/incubating'); // incubating: may change in future versions

const functionId = process.env.FUNCTION_ID || 'A';
const deploymentEnvironment =
  process.env.OTEL_DEPLOYMENT_ENVIRONMENT || process.env.DEPLOYMENT_ENVIRONMENT || 'local';

const resourceAttributes = {
  [ATTR_SERVICE_NAME]: process.env.OTEL_SERVICE_NAME || `function-${functionId.toLowerCase()}`,
  [ATTR_DEPLOYMENT_ENVIRONMENT_NAME]: deploymentEnvironment,
};

if (process.env.OTEL_SERVICE_NAMESPACE) {
  resourceAttributes[ATTR_SERVICE_NAMESPACE] = process.env.OTEL_SERVICE_NAMESPACE;
}

if (process.env.OTEL_SERVICE_VERSION) {
  resourceAttributes[ATTR_SERVICE_VERSION] = process.env.OTEL_SERVICE_VERSION;
}

const textMapPropagator = new CompositePropagator({
  propagators: [
    new W3CTraceContextPropagator(),
    new CloudPropagator(),
    new W3CBaggagePropagator(),
  ],
});

const sdk = new NodeSDK({
  resource: resourceFromAttributes(resourceAttributes),
  autoDetectResources: true,
  resourceDetectors: [gcpDetector],
  traceExporter: new OTLPTraceExporter(),
  textMapPropagator,
});

(async () => {
  try {
    await sdk.start();
  } catch (err) {
    console.error('Error starting OTel SDK', err);
  }
})();

async function shutdownAndExit(exitCode) {
  try {
    await sdk.shutdown();
    process.exit(exitCode);
  } catch (err) {
    console.error('Error shutting down OTel SDK', err);
    process.exit(1);
  }
}

process.on('SIGTERM', () => shutdownAndExit(0));
process.on('SIGINT', () => shutdownAndExit(0));

module.exports = { sdk };

Step 3. Load `tracing.js` before your function handler

Import tracing.js first, then keep your function logic as normal:

index.js

'use strict';

require('./tracing');

const functions = require('@google-cloud/functions-framework');

functions.http('entryPoint', (req, res) => {
  res.status(200).json({
    ok: true,
    message: req.query.message || 'Hello from Cloud Functions',
  });
});

Setup OpenTelemetry Collector (Optional)

What is the OpenTelemetry Collector?

Think of the OTel Collector as a middleman between your app and SigNoz. Instead of your application sending data directly to SigNoz, it sends everything to the Collector first, which then forwards it along.

Why use it?

Cleaning up data — Filter out noisy traces you don't care about, or remove sensitive info before it leaves your servers.
Keeping your app lightweight — Let the Collector handle batching, retries, and compression instead of your application code.
Adding context automatically — The Collector can tag your data with useful info like which Kubernetes pod or cloud region it came from.
Future flexibility — Want to send data to multiple backends later? The Collector makes that easy without changing your app.

See Switch from direct export to Collector for step-by-step instructions to convert your setup.

For more details, see Why use the OpenTelemetry Collector? and the Collector configuration guide.

Troubleshooting

Why don't traces appear in SigNoz?

Check that require('@opentelemetry/auto-instrumentations-node/register') is the first import in your index.js for the zero-code setup.
Check that OTEL_EXPORTER_OTLP_TRACES_ENDPOINT includes /v1/traces.
Check that OTEL_EXPORTER_OTLP_PROTOCOL is http/json.
Check that OTEL_EXPORTER_OTLP_HEADERS is exactly signoz-ingestion-key=<your-ingestion-key>.
Invoke the function a few times; cold starts can delay the first export.

Why do I see `Cannot find module '@opentelemetry/auto-instrumentations-node/register'`?

The auto-instrumentation package is missing from your deployment artifact. Re-run the package install step, redeploy, and invoke again.

Why not use `NODE_OPTIONS` in this guide?

Cloud Functions can reject reserved runtime environment variable names. This guide uses an explicit register import to avoid runtime env var conflicts.

Why do I see 401/403 from the SigNoz endpoint?

Your ingestion key is incorrect or missing. Recopy it from the SigNoz ingestion key page and redeploy.

Why is my service missing from the Services list?

Set OTEL_SERVICE_NAME to a stable value, redeploy, and invoke again.

Next steps

Correlate traces with logs to speed up debugging.
Create trace-based alerts for latency and error spikes.
Build dashboards for latency and error trends.

Prerequisites

A Google Cloud project with billing enabled.
Cloud Functions API enabled in your project.
A 2nd gen Cloud Function using Node.js 20.
A SigNoz Cloud account or self-hosted SigNoz instance.

Send traces to SigNoz

Step 1. Create an HTTP Cloud Function

In Google Cloud Console:

Open Cloud Functions and click Create function.
Select 2nd gen.
Set Runtime to Node.js 20.
Set Trigger to HTTP.

You will add runtime environment variables and code in the next steps.

Step 2. Configure OpenTelemetry environment variables.

In Runtime, build, connections and security settings -> Runtime environment variables, add:

OTEL_TRACES_EXPORTER=otlp
OTEL_EXPORTER_OTLP_PROTOCOL=http/json
OTEL_EXPORTER_OTLP_TRACES_ENDPOINT=https://ingest.<region>.signoz.cloud/v1/traces
OTEL_EXPORTER_OTLP_HEADERS=signoz-ingestion-key=<your-ingestion-key>
OTEL_SERVICE_NAME=<your-service-name>
OTEL_PROPAGATORS=tracecontext
OTEL_RESOURCE_ATTRIBUTES=deployment.environment.name=production

Verify these values:

<region>: Your SigNoz Cloud region.
<your-ingestion-key>: Your SigNoz ingestion key.
<your-service-name>: Name that will appear in SigNoz Services (for example, gcp-fn-orders).
OTEL_RESOURCE_ATTRIBUTES: Comma-separated resource attributes. Keep deployment.environment.name=production or set your environment value.

Step 3. Install the required packages

Run this in your Cloud Function project directory:

npm install --save \
  @google-cloud/functions-framework \
  @opentelemetry/api \
  @opentelemetry/auto-instrumentations-node \
  @opentelemetry/exporter-trace-otlp-http \
  @opentelemetry/sdk-node

This creates or updates package.json and package-lock.json with the dependencies used by the examples in this guide.

Step 4. Update `index.js`

Add the register import at the top of your entry file. Your handler code stays unchanged -- no manual tracing calls are needed.

index.js

'use strict';

require('@opentelemetry/auto-instrumentations-node/register');

const functions = require('@google-cloud/functions-framework');

functions.http('entryPoint', (req, res) => {
  res.status(200).json({
    ok: true,
    message: req.query.message || 'Hello from Cloud Functions',
  });
});

What this does:

The register import loads OpenTelemetry auto-instrumentation before your function handler code runs.
Common incoming/outgoing HTTP operations are traced automatically.

Step 5. Deploy and invoke the function

Deploy the function.
Copy the HTTPS trigger URL after deployment.
Invoke it once:

curl "https://<your-cloud-function-url>?message=hello-signoz"

Validate

After invoking the function, verify traces in SigNoz:

Open SigNoz and go to Services.
Find the service name you set in OTEL_SERVICE_NAME.
Open Traces and filter by service.name=<your-service-name>.
Open a trace and confirm request spans from your function are present.

Code-Based Setup (Optional)

Step 1. Install OpenTelemetry packages

npm install --save \
  @google-cloud/functions-framework \
  @google-cloud/opentelemetry-cloud-trace-propagator \
  @opentelemetry/core \
  @opentelemetry/exporter-trace-otlp-http \
  @opentelemetry/resource-detector-gcp \
  @opentelemetry/resources \
  @opentelemetry/sdk-node \
  @opentelemetry/semantic-conventions

Step 2. Create `tracing.js`

Create a new file named tracing.js in your function source.

tracing.js

'use strict';

const { NodeSDK } = require('@opentelemetry/sdk-node');
const {
  CompositePropagator,
  W3CBaggagePropagator,
  W3CTraceContextPropagator,
} = require('@opentelemetry/core');
const { CloudPropagator } = require('@google-cloud/opentelemetry-cloud-trace-propagator');
const { gcpDetector } = require('@opentelemetry/resource-detector-gcp');
const { OTLPTraceExporter } = require('@opentelemetry/exporter-trace-otlp-http');
const { resourceFromAttributes } = require('@opentelemetry/resources');
const {
  ATTR_SERVICE_NAME,
  ATTR_SERVICE_NAMESPACE,
  ATTR_SERVICE_VERSION,
} = require('@opentelemetry/semantic-conventions');
const { ATTR_DEPLOYMENT_ENVIRONMENT_NAME } = require('@opentelemetry/semantic-conventions/incubating'); // incubating: may change in future versions

const functionId = process.env.FUNCTION_ID || 'A';
const deploymentEnvironment =
  process.env.OTEL_DEPLOYMENT_ENVIRONMENT || process.env.DEPLOYMENT_ENVIRONMENT || 'local';

const resourceAttributes = {
  [ATTR_SERVICE_NAME]: process.env.OTEL_SERVICE_NAME || `function-${functionId.toLowerCase()}`,
  [ATTR_DEPLOYMENT_ENVIRONMENT_NAME]: deploymentEnvironment,
};

if (process.env.OTEL_SERVICE_NAMESPACE) {
  resourceAttributes[ATTR_SERVICE_NAMESPACE] = process.env.OTEL_SERVICE_NAMESPACE;
}

if (process.env.OTEL_SERVICE_VERSION) {
  resourceAttributes[ATTR_SERVICE_VERSION] = process.env.OTEL_SERVICE_VERSION;
}

const textMapPropagator = new CompositePropagator({
  propagators: [
    new W3CTraceContextPropagator(),
    new CloudPropagator(),
    new W3CBaggagePropagator(),
  ],
});

const sdk = new NodeSDK({
  resource: resourceFromAttributes(resourceAttributes),
  autoDetectResources: true,
  resourceDetectors: [gcpDetector],
  traceExporter: new OTLPTraceExporter(),
  textMapPropagator,
});

(async () => {
  try {
    await sdk.start();
  } catch (err) {
    console.error('Error starting OTel SDK', err);
  }
})();

async function shutdownAndExit(exitCode) {
  try {
    await sdk.shutdown();
    process.exit(exitCode);
  } catch (err) {
    console.error('Error shutting down OTel SDK', err);
    process.exit(1);
  }
}

process.on('SIGTERM', () => shutdownAndExit(0));
process.on('SIGINT', () => shutdownAndExit(0));

module.exports = { sdk };

Step 3. Load `tracing.js` before your function handler

Import tracing.js first, then keep your function logic as normal:

index.js

'use strict';

require('./tracing');

const functions = require('@google-cloud/functions-framework');

functions.http('entryPoint', (req, res) => {
  res.status(200).json({
    ok: true,
    message: req.query.message || 'Hello from Cloud Functions',
  });
});

Setup OpenTelemetry Collector (Optional)

What is the OpenTelemetry Collector?

Why use it?

Cleaning up data — Filter out noisy traces you don't care about, or remove sensitive info before it leaves your servers.
Keeping your app lightweight — Let the Collector handle batching, retries, and compression instead of your application code.
Adding context automatically — The Collector can tag your data with useful info like which Kubernetes pod or cloud region it came from.
Future flexibility — Want to send data to multiple backends later? The Collector makes that easy without changing your app.

See Switch from direct export to Collector for step-by-step instructions to convert your setup.

For more details, see Why use the OpenTelemetry Collector? and the Collector configuration guide.

Troubleshooting

Why don't traces appear in SigNoz?

Check that require('@opentelemetry/auto-instrumentations-node/register') is the first import in your index.js for the zero-code setup.
Check that OTEL_EXPORTER_OTLP_TRACES_ENDPOINT includes /v1/traces.
Check that OTEL_EXPORTER_OTLP_PROTOCOL is http/json.
Check that OTEL_EXPORTER_OTLP_HEADERS is exactly signoz-ingestion-key=<your-ingestion-key>.
Invoke the function a few times; cold starts can delay the first export.

Why do I see `Cannot find module '@opentelemetry/auto-instrumentations-node/register'`?

The auto-instrumentation package is missing from your deployment artifact. Re-run the package install step, redeploy, and invoke again.

Why not use `NODE_OPTIONS` in this guide?

Cloud Functions can reject reserved runtime environment variable names. This guide uses an explicit register import to avoid runtime env var conflicts.

Why do I see 401/403 from the SigNoz endpoint?

Your ingestion key is incorrect or missing. Recopy it from the SigNoz ingestion key page and redeploy.

Why is my service missing from the Services list?

Set OTEL_SERVICE_NAME to a stable value, redeploy, and invoke again.

Next steps

Correlate traces with logs to speed up debugging.
Create trace-based alerts for latency and error spikes.
Build dashboards for latency and error trends.

Cloud Functions OpenTelemetry Tracing

Prerequisites

Send traces to SigNoz

Step 1. Create an HTTP Cloud Function

Step 2. Configure OpenTelemetry environment variables.

Step 3. Install the required packages

Step 4. Update index.js

Step 5. Deploy and invoke the function

Validate

Code-Based Setup (Optional)

Step 1. Install OpenTelemetry packages

Step 2. Create tracing.js

Step 3. Load tracing.js before your function handler

Setup OpenTelemetry Collector (Optional)

What is the OpenTelemetry Collector?

Why use it?

Troubleshooting

Why don't traces appear in SigNoz?

Why do I see Cannot find module '@opentelemetry/auto-instrumentations-node/register'?

Why not use NODE_OPTIONS in this guide?

Why do I see 401/403 from the SigNoz endpoint?

Why is my service missing from the Services list?

Next steps

Was this page helpful?

Is this page helpful?

Cloud Functions OpenTelemetry Tracing

Prerequisites

Send traces to SigNoz

Step 1. Create an HTTP Cloud Function

Step 2. Configure OpenTelemetry environment variables.

Step 3. Install the required packages

Step 4. Update index.js

Step 5. Deploy and invoke the function

Validate

Code-Based Setup (Optional)

Step 1. Install OpenTelemetry packages

Step 2. Create tracing.js

Step 3. Load tracing.js before your function handler

Setup OpenTelemetry Collector (Optional)

What is the OpenTelemetry Collector?

Why use it?

Troubleshooting

Why don't traces appear in SigNoz?

Why do I see Cannot find module '@opentelemetry/auto-instrumentations-node/register'?

Why not use NODE_OPTIONS in this guide?

Why do I see 401/403 from the SigNoz endpoint?

Why is my service missing from the Services list?

Next steps

Was this page helpful?

Is this page helpful?

Step 4. Update `index.js`

Step 2. Create `tracing.js`

Step 3. Load `tracing.js` before your function handler

Why do I see `Cannot find module '@opentelemetry/auto-instrumentations-node/register'`?

Why not use `NODE_OPTIONS` in this guide?

Step 4. Update `index.js`

Step 2. Create `tracing.js`

Step 3. Load `tracing.js` before your function handler

Why do I see `Cannot find module '@opentelemetry/auto-instrumentations-node/register'`?

Why not use `NODE_OPTIONS` in this guide?