function main(projectId, zone, instanceName, customImageLink) {
  // [START compute_instances_create_from_custom_image]
  /**
   * TODO(developer): Uncomment and replace these variables before running the sample.
   */
  // const projectId = 'YOUR_PROJECT_ID';
  // const zone = 'europe-central2-b';
  // const instanceName = 'YOUR_INSTANCE_NAME';
  // const customImageLink = 'projects/YOUR_PROJECT/global/images/YOUR_IMAGE_NAME';

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

  // Creates a new VM instance with custom image used as its boot disk.
  async function createInstanceFromCustomImage() {
    const instancesClient = new compute.InstancesClient();

    const [response] = await instancesClient.insert({
      project: projectId,
      zone,
      instanceResource: {
        name: instanceName,
        disks: [
          {
            initializeParams: {
              diskSizeGb: '10',
              sourceImage: customImageLink,
              diskType: `zones/${zone}/diskTypes/pd-standard`,
            },
            autoDelete: true,
            boot: true,
            type: 'PERSISTENT',
          },
        ],
        machineType: `zones/${zone}/machineTypes/n1-standard-1`,
        networkInterfaces: [
          {
            name: 'global/networks/default',
          },
        ],
      },
    });
    let operation = response.latestResponse;
    const operationsClient = new compute.ZoneOperationsClient();

    // Wait for the create operation to complete.
    while (operation.status !== 'DONE') {
      [operation] = await operationsClient.wait({
        operation: operation.name,
        project: projectId,
        zone: operation.zone.split('/').pop(),
      });
    }

    console.log('Instance created.');
  }

  createInstanceFromCustomImage();
  // [END compute_instances_create_from_custom_image]
}
Creates a new VM instance with custom image used as its boot disk.

@param {string} projectId - Project ID or project number of the Cloud project you want to use.
@param {string} zone - Name of the zone to create the instance in. For example: "us-west3-b"
@param {string} instanceName - Name of the new virtual machine (VM) instance.
@param {string} customImageLink - Link to the custom image you want to use in the form of:
  "projects/{project_name}/global/images/{image_name}"