backend_client: update 3scale backend status metric

gateway/src/apicast/backend_client.lua

@@ -20,6 +20,7 @@ local http_ng = require('resty.http_ng')
 local user_agent = require('apicast.user_agent')
 local resty_url = require('resty.url')
 local resty_env = require('resty.env')
+local threescale_backend_status_counters = require('apicast.metrics.3scale_backend_status')
 
 local http_proxy = require('resty.http.proxy')
 local http_ng_ngx = require('resty.http_ng.backend.ngx')
@@ -97,6 +98,10 @@ function _M:new(service, http_client)
   }, mt)
 end
 
+local function inc_backend_status_metric(status)
+  threescale_backend_status_counters.inc(status)
+end
+
 local function build_args(args)
   local query = {}
 
@@ -133,6 +138,8 @@ local function call_backend_transaction(self, path, options, ...)
 
   ngx.log(ngx.INFO, 'backend client uri: ', url, ' ok: ', res.ok, ' status: ', res.status, ' body: ', res.body, ' error: ', res.error)
 
+  inc_backend_status_metric(res.status)
+
   return res
 end
 
@@ -229,6 +236,8 @@ function _M:report(reports_batch)
   local report_body = format_transactions(reports_batch)
   local res = http_client.post(report_uri, report_body)
 
+  inc_backend_status_metric(res.status)
+
   return res
 end