Sending metrics with Prometheus

In this guide we show how to configure a Prometheus instance to securely send metrics to your Opstrace cluster.

Prerequisites

  • An Opstrace cluster.
  • A decision: for which Opstrace tenant would you like to send data?
  • An Opstrace tenant authentication token file (for the tenant of your choice). Also see concepts.

remote_write configuration block: the basics

A Prometheus instance can be instructed to replicate its state to a remote system by defining a remote_write configuration block.

What follows is the basic structure of this configuration block to make Prometheus send data to your Opstrace cluster:

remote_write:
- url: <string>
bearer_token_file: <filename>
tls_config:
insecure_skip_verify: <boolean>

Choosing url

This is the tenant-specific data API endpoint of an Opstrace cluster for ingesting metrics. The endpoint URL is constructed using the tenant name and the cluster name:

url: https://cortex.${TENANT_NAME}.${CLUSTER_NAME}.opstrace.io/api/v1/push

Example:

url: https://cortex.default.testcluster.opstrace.io/api/v1/push

Choosing bearer_token_file

Your Opstrace cluster exposes the metrics ingestion API securely. For authenticating the client towards the Opstrace cluster, the client has to present a tenant-specific data API authentication token with every request.

To achieve that, we use the bearer_token_file parameter:

Example:

bearer_token_file: /var/run/default-tenant/tenant-api-token-default

Choosing tls_config

TLS is used for establishing a secure, private transport between the Prometheus instance and the Opstrace cluster. By default, the Prometheus instance attempts to verify the certificate exposed by the Opstrace cluster against its trust store, for establishing authenticity of the Opstrace cluster towards Prometheus. Depending on the cert_issuer cluster configuration option (see cluster configuration) you may want to disable server certificate verification for testing purposes.

This can be achieved via

tls_config:
insecure_skip_verify: true

This is required for example when using letsencrypt-staging as cert_issuer.

Further references

The following resources provide further assistance in understanding and configuring Prometheus' remote_write protocol: