frontend

Frontend

The frontend binary is a thin query frontend for Google Cloud Managed Service for Prometheus (GMP) that looks and feels like a regular Prometheus server. It primarily serves as a target URL for a Prometheus datasource in Grafana and to access GMP via the well-known Prometheus UI.

Currently, the following API endpoints are supported:

• api/v1/query
• api/v1/query_range
• api/v1/label/__name__/values

Spinup

The frontend authenticates to GMP with credentials (typically a service account) and re-exposes the JSON/HTTP API unauthenticated (or for use with a custom authentication mechanism).

A frontend instance serves read traffic for a single Google Cloud Monitoring workspace, identified by the project.

PROJECT_ID=$(gcloud config get-value core/project)
# Default gcloud credentials. Substitute for service account key in production.
CREDENTIALS=$HOME/.config/gcloud/application_default_credentials.json

For example, from this directory:

bash ../../pkg/ui/build.sh # If you want to use UI.
go run main.go \
  --web.listen-address=:19090 \
  --query.credentials-file=$CREDENTIALS \
  --query.project-id=$PROJECT_ID

Access the frontend UI in your browser at http://localhost:19090.

Docker

You can also build a docker image from source using make frontend.

Authentication

The frontend supports incoming authentication using basic auth by providing a username and password on the incoming request. These are validated against the AUTH_USERNAME and AUTH_PASSWORD environment variables, which must be set on the frontend pod.

UI Development

Refer to pkg/ui for more information on how to develop or update UI.