Handle EC keys for GDCH/ GDC air gapped inside the googlecloud secretstore

[ZPascal]

Relevant telegraf.conf

[agent]
  metric_buffer_limit = 1800
  collection_jitter = "30s"
  flush_interval = "10s"
  flush_jitter = "5s"

[[secretstores.googlecloud]]
  id = "gdcloud_secret"
  credentials_file = "/etc/gdc_service_account.json"
  sts_audience = "https://service-accounts.test-domain/authenticate"

Logs from Telegraf

2025-12-11T15:26:40Z E! loading config file /telegraf.conf failed: error parsing googlecloud, error initializing secret-store "gdcloud_secret": credentials search failed: private key should be a PEM or plain PKCS1 or PKCS8: x509: failed to parse private key (use ParseECPrivateKey instead for this key format)

System info

Telegraf 1.37.0

Docker

No response

Steps to reproduce

1. Use the config and start Telegraf on a GDC environment
2. Use EC as PKey inside the service accounts

Expected behavior

The STS token should be requested from the appropriate endpoint.

Actual behavior

It is not possible to get the token.

Additional info

No response