Merge pull request #9 from yciabaud/fixes

Remove init and admin errors

api.lua

@@ -16,8 +16,7 @@ return {
         logger:logAdmin(plugin.config)
       end 
 
-      logger:collect()
-      helpers.responses.send_HTTP_OK()  
+      return logger:collect()
     end
   }
 }

logger.lua

@@ -17,7 +17,10 @@ end
 
 local function update_metric(metric_name, stat_type, stat_value, label_values)
   ngx_log(NGX_DEBUG, string.format("Prometheus: log metric %s (%s)", metric_name, stat_type))
-
+  if metrics == nil then
+    ngx_log(NGX_ERR, string.format("Prometheus: metrics dictionary not found"))
+    return
+  end
   local metric = metrics[metric_name]
   if metric == nil then
     ngx_log(NGX_ERR, string.format("Prometheus: metrics %s not found", metric_name))
@@ -68,6 +71,11 @@ function PrometheusLogger:init(config)
 end
 
 function PrometheusLogger:log(message, config)
+  if prometheus == nil then
+    ngx_log(NGX_DEBUG, string.format("Prometheus: plugin not initialized"))
+    PrometheusLogger:init(config)
+    return
+  end
   ngx_log(NGX_DEBUG, "Prometheus: logging metrics...")
 
   local api_name
@@ -77,11 +85,11 @@ function PrometheusLogger:log(message, config)
     api_name = string_gsub(message.api.name, "%.", "_")
   end
   local stat_value = {
-    http_request_size_bytes   = tonumber(message.request.size),
-    http_response_size_bytes  = tonumber(message.response.size),
-    http_request_duration_ms  = message.latencies.request,
-    http_upstream_duration_ms = message.latencies.proxy,
-    http_kong_duration_ms     = message.latencies.kong,
+    http_request_size_bytes        = tonumber(message.request.size),
+    http_response_size_bytes       = tonumber(message.response.size),
+    http_request_duration_ms       = tonumber(message.latencies.request),
+    http_upstream_duration_ms      = tonumber(message.latencies.proxy),
+    http_kong_duration_ms          = tonumber(message.latencies.kong),
     http_requests_total            = 1,
   }
 
@@ -108,6 +116,11 @@ function PrometheusLogger:log(message, config)
 end
 
 function PrometheusLogger:logAdmin(config)
+  if prometheus == nil then
+    ngx_log(NGX_DEBUG, string.format("Prometheus: plugin not initialized"))
+    PrometheusLogger:init(config)
+    return
+  end
   ngx_log(NGX_DEBUG, "Prometheus: logging metrics admin...")
 
   local stat_value
@@ -153,6 +166,10 @@ function PrometheusLogger:logAdmin(config)
 end
 
 function PrometheusLogger:collect()
+  if prometheus == nil then
+    ngx_log(NGX_ERR, string.format("Prometheus: plugin not initialized properly"))
+    return
+  end
   prometheus:collect()
 end
 

prometheus.lua

@@ -39,6 +39,8 @@
 -- https://github.com/knyar/nginx-lua-prometheus
 -- Released under MIT license.
 
+local ngx_log       = ngx.log
+local NGX_ERR       = ngx.ERR
 
 -- Default set of latency buckets, 5ms to 10s:
 local DEFAULT_BUCKETS = {0.005, 0.01, 0.02, 0.03, 0.05, 0.075, 0.1, 0.2, 0.3,
@@ -268,6 +270,10 @@ end
 function Prometheus.init(dict_name, prefix)
   local self = setmetatable({}, Prometheus)
   self.dict = ngx.shared[dict_name or "kong_cache"]
+  if self.dict == nil then
+    ngx_log(NGX_ERR, string.format("Prometheus: dictionary %s not available", dict_name or "kong_cache"))
+    return
+  end
   self.help = {}
   if prefix then
     self.prefix = prefix
@@ -494,6 +500,7 @@ end
 -- It will get the metrics from the dictionary, sort them, and expose them
 -- aling with TYPE and HELP comments.
 function Prometheus:collect()
+  ngx.status = 200
   ngx.header.content_type = "text/plain"
   if not self.initialized then
     ngx.log(ngx.ERR, "Prometheus module has not been initialized")
@@ -528,6 +535,7 @@ function Prometheus:collect()
       end
     end
   end
+  return ngx.exit(200)
 end
 
 return Prometheus