So I’m trying to use an environment variable for configuration of promtail clients per the documentation at the grafana documentation
scrape_configs:
- job_name: varlogs
ec2_sd_configs:
- role_arn: ${INSTANCE_PROFILE_ARN}
Here, I’m trying to set the INSTANCE_PROFILE_ARN for EC2 discovery so that we can accomplish interactions via the instance profile rather than Secret / Key etc. Promtail will start and scrape, but it fails accessing AWS:
is not authorized to perform: sts:AssumeRole on resource: ${INSTANCE_PROFILE_ARN}
I thought it might have been caused by not having a default, but if I put anything in that structure as a default (ie ${INSTANCE_PROFILE_ARN:123}
), it just prints that raw text.
My gut feeling is that because these are basically part of the prometheus definitions for scrape configs, variable interpolation isn’t happening.