Documentation Grafana Cloud Instrument and send data Grafana Alloy Reference Components discovery discovery.gce

discovery.gce

discovery.gce allows retrieving scrape targets from Google Compute Engine (GCE) instances. The private IP address is used by default, but may be changed to the public IP address with relabeling.

Credentials are discovered by the Google Cloud SDK default client by looking in the following places, preferring the first location found:

1. A JSON file specified by the GOOGLE_APPLICATION_CREDENTIALS environment variable.
2. A JSON file in the well-known path $HOME/.config/gcloud/application_default_credentials.json.
3. Fetched from the GCE metadata server.

If Alloy is running within GCE, the service account associated with the instance it’s running on should have at least read-only permissions to the compute resources. If running outside of GCE make sure to create an appropriate service account and place the credential file in one of the expected locations.

Usage

alloy Copy

discovery.gce "LABEL" {
  project = PROJECT_NAME
  zone    = ZONE_NAME
}

Arguments

The following arguments are supported:

For more information on the syntax of the filter argument, refer to Google’s filter documentation for Method: instances.list.

Exported fields

The following fields are exported and can be referenced by other components:

Each target includes the following labels:

• __meta_gce_instance_id: the numeric id of the instance
• __meta_gce_instance_name: the name of the instance
• __meta_gce_label_LABEL_NAME: each GCE label of the instance
• __meta_gce_machine_type: full or partial URL of the machine type of the instance
• __meta_gce_metadata_NAME: each metadata item of the instance
• __meta_gce_network: the network URL of the instance
• __meta_gce_private_ip: the private IP address of the instance
• __meta_gce_interface_ipv4_NAME: IPv4 address of each named interface
• __meta_gce_project: the GCP project in which the instance is running
• __meta_gce_public_ip: the public IP address of the instance, if present
• __meta_gce_subnetwork: the subnetwork URL of the instance
• __meta_gce_tags: comma separated list of instance tags
• __meta_gce_zone: the GCE zone URL in which the instance is running

Component health

discovery.gce is only reported as unhealthy when given an invalid configuration. In those cases, exported fields retain their last healthy values.

Debug information

discovery.gce does not expose any component-specific debug information.

Debug metrics

discovery.gce does not expose any component-specific debug metrics.

Example

alloy Copy

discovery.gce "gce" {
  project = "alloy"
  zone    = "us-east1-a"
}

prometheus.scrape "demo" {
  targets    = discovery.gce.gce.targets
  forward_to = [prometheus.remote_write.demo.receiver]
}

prometheus.remote_write "demo" {
  endpoint {
    url = PROMETHEUS_REMOTE_WRITE_URL

    basic_auth {
      username = USERNAME
      password = PASSWORD
    }
  }
}

Replace the following:

• PROMETHEUS_REMOTE_WRITE_URL: The URL of the Prometheus remote_write-compatible server to send metrics to.
• USERNAME: The username to use for authentication to the remote_write API.
• PASSWORD: The password to use for authentication to the remote_write API.

Compatible components

discovery.gce has exports that can be consumed by the following components:

• Components that consume Targets