"no token found" when scraping from Promethues - kubernetes

Question

I am using Promethues to monitor my Kubernetes cluster. All my microservices can be accessed using my HA Proxy.
My base Promethues config is :
- job_name: 'kubernetes_pods'
tls_config:
insecure_skip_verify: true
kubernetes_sd_configs:
- api_server: http://172.29.219.102:8080
role: pod
relabel_configs:
- source_labels: [__meta_kubernetes_pod_host_ip]
target_label: __address__
regex: (.*)
replacement: 172.29.219.110:8080
Where 172.29.219.110:8080 is the IP & Port of my standalone HA Proxy.
The endpoint that I am trying to monitor using Prometheus is /auth/health.
When I do a simple curl command from anywhere, I see :
# curl http://172.29.219.110:8080/auth/health
{"status":"UP"}
But when Prometheus tries to do it, the logs indicate :
level=warn ts=2017-12-15T16:40:48.301741927Z caller=scrape.go:673 component="target manager" scrape_pool=kubernetes_pods target=http://172.29.219.110:8080/auth/health msg="append failed" err="no token found"
This endpoint is publicly exposed and requires no authentication what so ever. So why does Promethues say :

Answer 1

{"status":"UP"}
Prometheus requires data to be in its format, and cannot handle other arbitrary data. The error you are getting is a parse error due to this.
You should instrument your code using a client library, and have it expose data in the Prometheus text format.