How to handle prometheus remote_write case with influxdb-relay

[Alexvianet]

influxdata/influxdb-relay#66

URL for relevant page?

influxdata/influxdb-relay#66

What products and version are you using?

latest

Where did you look before opening the issue?

how should i configure relay in prometheus case
prometheus config:

# Remote write configuration (for Graphite, OpenTSDB, or InfluxDB).
remote_write:
  - url: "http://relay.Loadbalancer:9096/api/v1/prom/write?u=foo&p=bar&db=prometheus"

relay config:

bind-addr = "0.0.0.0:9096"
# Array of InfluxDB instances to use as backends for Relay.
output = [

 { name="influxdb1", location="http://10.35.96.144:8086/write", timeout="10s" },
 { name="influxdb2", location="http://10.35.96.145:8086/write", timeout="10s" },

]

Loadbalancer nginx config:

http {
  client_max_body_size 20M;
  sendfile    on;
  tcp_nopush  on;
  tcp_nodelay on;

  upstream influxdb-relay {

    server relay:9096 fail_timeout=0;
  }
  upstream influxdb {

    server influxdb1:8086 fail_timeout=0;
    server influxdb2:8086 fail_timeout=0;
  }

  server {
    listen                  9096;
    server_name             relay.Loadbalancer;

    location /write {
      limit_except POST {
        deny all;
                        }
      proxy_pass http://influxdb-relay;
                    }
    location /api/v1/prom/write {
      limit_except POST {
        deny all;
                        }
      proxy_pass http://influxdb-relay;
                    }
        }

  server {
    listen                  8086;
    server_name             influxdb.Loadbalancer;
    location /query {
      limit_except GET {
        deny all;
    }

    proxy_pass http://influxdb;

  }
    location /read {
      limit_except GET {
        deny all;
    }

    proxy_pass http://influxdb;

  }
    location /api/v1/prom/read {
      limit_except GET {
        deny all;
    }

    proxy_pass http://influxdb;

  }
 }
}

and get error
2018/06/01 14:08:02 [error] 10360#0: *69959 readv() failed (104: Connection reset by peer) while reading upstream, client: prometheus_host, server: relay.Loadbalancer, request: "POST /api/v1/prom/write?u=foo&p=bar&db=prometheus HTTP/1.1", upstream: "http://relay:9096/api/v1/prom/write?u=foo&p=bar&db=prometheus", host: "relay.Loadbalancer:9096"

Runing on relay server:
curl -i -XPOST 'http://localhost:9096/api/v1/prom/write?u=foo&p=bar&db=prometheus' --data-binary 'cpu_load_short,host=server01,region=us-west value=22.64 1434055562000000000'

gives:

HTTP/1.1 404 Not Found
Content-Length: 35
Content-Type: application/json
Date: Mon, 04 Jun 2018 11:32:54 GMT

{"error":"invalid write endpoint"}

[stevebang]

This is an influxdb-relay issue, which is not documented in the InfluxData docs. Also, AFAIK, influxdb-relay is not supported. @Alexvianet -- you can try adding this issue in the influxdata/influxdb-relay repository.