promtail-rancher

This is a customized Docker image of grafana/promtail with configuration to scrape logs from Docker and apply labels from Rancher 1.6 labels.

When deploying this image, it needs privileged access to the host and the Docker socket /var/run/docker.sock mounted and accessible in the image.

Environment configuration:

LOKI_URL the URL for the Loki server (default: http://loki:3100/loki/api/v1/push)
TENANT_ID the Loki tenant ID (default: manas)
ENVIRONMENT the value for a static label env applied to all pushed logs

The pushed logs have extra labels:

container computed from the Docker container name
stack_service computed from the container label io.rancher.stack_service.name

Also, logs for Rancher system containers (ie. those with a label io.rancher.container.system=true) are not pushed.