gcp-metadata

Get the metadata from a Google Cloud Platform environment.

$ npm install --save gcp-metadata

const gcpMetadata = require('gcp-metadata');

Check to see if the metadata server is available

const isAvailable = await gcpMetadata.isAvailable();

Access all metadata

const data = await gcpMetadata.instance();
console.log(data); // ... All metadata properties

Access specific properties

const data = await gcpMetadata.instance('hostname');
console.log(data); // ...Instance hostname
const projectId = await gcpMetadata.project('project-id');
console.log(projectId); // ...Project ID of the running instance

Access nested properties with the relative path

const data = await gcpMetadata.instance('service-accounts/default/email');
console.log(data); // ...Email address of the Compute identity service account

Access specific properties with query parameters

const data = await gcpMetadata.instance({
  property: 'tags',
  params: { alt: 'text' }
});
console.log(data) // ...Tags as newline-delimited list

Access with custom headers

await gcpMetadata.instance({
  headers: { 'no-trace': '1' }
}); // ...Request is untraced

Take care with large number valued properties

In some cases number valued properties returned by the Metadata Service may be too large to be representable as JavaScript numbers. In such cases we return those values as BigNumber objects (from the bignumber.js library). Numbers that fit within the JavaScript number range will be returned as normal number values.

const id = await gcpMetadata.instance('id');
console.log(id)  // ... BigNumber { s: 1, e: 18, c: [ 45200, 31799277581759 ] }
console.log(id.toString()) // ... 4520031799277581759

Environment variables

• GCE_METADATA_HOST: provide an alternate host or IP to perform lookup against (useful, for example, you're connecting through a custom proxy server).

For example:

export GCE_METADATA_HOST = '169.254.169.254'

• DETECT_GCP_RETRIES: number representing number of retries that should be attempted on metadata lookup.