HAProxy plugin

[v9n]

Request HAProxy stats in CSV format and parse only below value:

QCUR:
SCUR:
SMAX:
BIN:
BOUT:
RATE:
RATE_MAX:
STOT:
HRSP_1xx:
HRSP_2xx:
HRSP_3xx:
HRSP_4xx:
EREQ:
ERESP:
ECON:
REQ_RATE:
REQ_RATE_MAX:
REQ_TOT

Metric name is column name in CSV file as above to avoid confusion and keep it in-sync with HAProxy column. Proxy name and backend, service are passed as tag. Example(when run in test mode)

> [host="lb.haproxy.com" proxy="be_forbidden" sv="BACKEND"] haproxy_rate value=0
> [host="lb.haproxy.com" proxy="stats" sv="FRONTEND"] haproxy_scur value=1
> [host="lb.haproxy.com" proxy="stats" sv="FRONTEND"] haproxy_smax value=1
> [host="lb.haproxy.com" proxy="stats" sv="FRONTEND"] haproxy_stot value=2
> [host="lb.haproxy.com" proxy="stats" sv="FRONTEND"] haproxy_bin value=58504
> [host="lb.haproxy.com" proxy="stats" sv="FRONTEND"] haproxy_bot value=4314106
> [host="lb.haproxy.com" proxy="stats" sv="FRONTEND"] haproxy_rate value=1
> [host="lb.haproxy.com" proxy="stats" sv="FRONTEND"] haproxy_req_rate value=1
> [host="lb.haproxy.com" proxy="stats" sv="BACKEND"] haproxy_qcur value=0
> [host="lb.haproxy.com" proxy="stats" sv="BACKEND"] haproxy_scur value=0
> [host="lb.haproxy.com" proxy="stats" sv="BACKEND"] haproxy_smax value=0
> [host="lb.haproxy.com" proxy="stats" sv="BACKEND"] haproxy_stot value=0
> [host="lb.haproxy.com" proxy="stats" sv="BACKEND"] haproxy_bin value=58504
> [host="lb.haproxy.com" proxy="stats" sv="BACKEND"] haproxy_bot value=4314106
> [host="lb.haproxy.com" proxy="stats" sv="BACKEND"] haproxy_rate value=0

Sample configuration:

# Read metrics from one or many haproxy servers, either using socket or static http page
[haproxy]
servers = ["http://user:password@lb.haproxy.com", "http://noauthentication_haproxy.com"]

[evanphx]

One quick change I'd like you to make. Because the fields are NOT defined by Go, but rather in the CSV layout, please don't use iota. Instead use the constant numbers for the fields.

[v9n]

@evanphx Thanks for feedback. I was lazy so I used iota and make sure to map them one by one sequentially. But that's really bad after reading your comment now.

I rebased with master and solve conflict.

[sparrc]

@kureikain looks good to me, thanks much!