WIP feat: support customizing additional labels of metrics

apisix/plugins/prometheus/exporter.lua

@@ -45,6 +45,8 @@ local metrics = {}
 
 local inner_tab_arr = {}
 
+local additional_label_names = {}
+
 local function gen_arr(...)
     clear_tab(inner_tab_arr)
     for i = 1, select('#', ...) do
@@ -81,6 +83,7 @@ function _M.init()
     if attr and attr.metric_prefix then
         metric_prefix = attr.metric_prefix
     end
+    additional_label_names = attr.labels or {}
 
     prometheus = base_prometheus.init("prometheus-metrics", metric_prefix)
     metrics.connections = prometheus:gauge("nginx_http_current_connections",
@@ -109,15 +112,17 @@ function _M.init()
     -- no consumer in request.
     metrics.status = prometheus:counter("http_status",
             "HTTP status codes per service in APISIX",
-            {"code", "route", "matched_uri", "matched_host", "service", "consumer", "node"})
+            {"code", "route", "matched_uri", "matched_host", "service", "consumer", "node",
+            table.unpack(additional_label_names)})
 
     metrics.latency = prometheus:histogram("http_latency",
         "HTTP request latency in milliseconds per service in APISIX",
-        {"type", "route", "service", "consumer", "node"}, DEFAULT_BUCKETS)
+        {"type", "route", "service", "consumer", "node", table.unpack(additional_label_names)}
+        , DEFAULT_BUCKETS)
 
     metrics.bandwidth = prometheus:counter("bandwidth",
             "Total bandwidth in bytes consumed per service in APISIX",
-            {"type", "route", "service", "consumer", "node"})
+            {"type", "route", "service", "consumer", "node", table.unpack(additional_label_names)})
 
 end
 
@@ -149,28 +154,38 @@ function _M.log(conf, ctx)
         matched_uri = ctx.curr_req_matched._path or ""
         matched_host = ctx.curr_req_matched._host or ""
     end
+
+    local additional_label_values = {}
+    for i, name in pairs(additional_label_names) do
+        table.insert(additional_label_values, vars[name])
+    end
 
     metrics.status:inc(1,
         gen_arr(vars.status, route_id, matched_uri, matched_host,
-                service_id, consumer_name, balancer_ip))
+                service_id, consumer_name, balancer_ip, table.unpack(additional_label_values)))
 
     local latency, upstream_latency, apisix_latency = latency_details(ctx)
     metrics.latency:observe(latency,
-        gen_arr("request", route_id, service_id, consumer_name, balancer_ip))
+        gen_arr("request", route_id, service_id, consumer_name, balancer_ip,
+        table.unpack(additional_label_values)))
 
     if upstream_latency then
         metrics.latency:observe(upstream_latency,
-            gen_arr("upstream", route_id, service_id, consumer_name, balancer_ip))
+            gen_arr("upstream", route_id, service_id, consumer_name, balancer_ip,
+            table.unpack(additional_label_values)))
     end
 
     metrics.latency:observe(apisix_latency,
-        gen_arr("apisix", route_id, service_id, consumer_name, balancer_ip))
+        gen_arr("apisix", route_id, service_id, consumer_name, balancer_ip,
+        table.unpack(additional_label_values)))
 
     metrics.bandwidth:inc(vars.request_length,
-        gen_arr("ingress", route_id, service_id, consumer_name, balancer_ip))
+        gen_arr("ingress", route_id, service_id, consumer_name, balancer_ip,
+        table.unpack(additional_label_values)))
 
     metrics.bandwidth:inc(vars.bytes_sent,
-        gen_arr("egress", route_id, service_id, consumer_name, balancer_ip))
+        gen_arr("egress", route_id, service_id, consumer_name, balancer_ip,
+        table.unpack(additional_label_values)))
 end
 
 

conf/config-default.yaml

@@ -438,6 +438,9 @@ plugin_attr:
     export_addr:
       ip: 127.0.0.1
       port: 9091
+        #    labels:
+        #remote_addr: $remote_addr
+        #request_method: $request_method
   server-info:
     report_interval: 60  # server info report interval (unit: second)
     report_ttl: 3600     # live time for server info in etcd (unit: second)

docs/en/latest/plugins/prometheus.md

@@ -129,10 +129,28 @@ Here is an example:
 
 ```yaml
 plugin_attr:
-  prometheus:
+prometheus:
     export_uri: /apisix/metrics
 ```
 
+## How to custom additional labels
+
+The plugin is supported to custom labels for metrics, `Status codes` and `Latency`, in the `plugin_attr` section of `conf/config.yaml`
+
+| Name       | Type   | Default | Description                       |
+| ---------- | ------ | ------- | --------------------------------- |
+| labels     | array  |         | custom labels from [Nginx variables](http://nginx.org/en/docs/varindex.html) |
+
+Here is an example:
+
+```yaml:
+plugin_attr:
+  prometheus:
+    labels:
+      - request_method
+      - server_addr
+```
+
 ### Grafana dashboard
 
 Metrics exported by the plugin can be graphed in Grafana using a drop in dashboard.

docs/zh/latest/plugins/prometheus.md

@@ -132,6 +132,24 @@ plugin_attr:
     export_uri: /apisix/metrics
 ```
 
+## 如何自定义附加标签
+
+该插件支持在`conf/config`的`plugin_attr`部分自定义度量标签`Status codes`和`Latency`。亚马尔`
+
+| 名称       | 类型   | 默认值   | 描述                       
+| --------- | ----- | -------- | ------------------------- |
+| labels    | array |          | 使用 [Nginx 变量](http://nginx.org/en/docs/varindex.html)作为自定义标签 |
+
+下面是一个例子：
+
+```yaml:
+plugin_attr:
+  prometheus:
+    labels:
+      - request_method
+      - server_addr
+```
+
 ### Grafana 面板
 
 插件导出的指标可以在 Grafana 进行图形化绘制显示。