Prometheus 监控 Nginx

前言

Nginx 官网有介绍各种监控方案，以前我们常用 stub_status 和 Log 日志来实现 Nginx 监控。本文主要介绍基于 Prometheus 的 2 种监控方案 nginx-lua-prometheus 和 nginx-vts-exporter，在真实的生产环境中你可能需要研究和选择哪种方法才是适合你的，F5 收购 Nginx 后的未来让我们一起拭目以待。

Prometheus 监控 Nginx

扩展阅读

Monitoring NGINX - https://www.nginx.com/blog/monitoring-nginx/

Nginx 监控

官网介绍的监控方案 - https://www.nginx.com/blog/monitoring-nginx/

Prometheus 集成的 HTTP exporter 方案 - https://prometheus.io/docs/instrumenting/exporters/#http

聊聊 Nginx 的监控 - https://zhuanlan.zhihu.com/p/34050716

使用 rpmbuild 制作 Nginx 的 RPM 包 - https://wsgzao.github.io/post/rpmbuild/

Prometheus 监控 Nginx

nginx-lua-prometheus

Nginx 需要添加 Lua 扩展

https://github.com/knyar/nginx-lua-prometheus

# 下载 redis_exporter
https://github.com/knyar/nginx-lua-prometheus/releases
wget https://github.com/knyar/nginx-lua-prometheus/archive/0.20181120.tar.gz
tar xf 0.20181120.tar.gz
cd nginx-lua-prometheus-0.20181120

# 创建 prometheus.lua 目录 
mkdir -p /etc/nginx/lua/
cp prometheus.lua /etc/nginx/lua/

# 编辑 nginx 配置文件修改，注意修改 lua_package_path "/etc/nginx/lua/prometheus.lua";
vim /etc/nginx/nginx.conf

lua_shared_dict prometheus_metrics 10M;
lua_package_path "/etc/nginx/lua/prometheus.lua";
init_by_lua '
  prometheus = require("prometheus").init("prometheus_metrics")
  metric_requests = prometheus:counter(
"nginx_http_requests_total","Number of HTTP requests", {"host","status"})
  metric_latency = prometheus:histogram(
"nginx_http_request_duration_seconds","HTTP request latency", {"host"})
  metric_connections = prometheus:gauge(
"nginx_http_connections","Number of HTTP connections", {"state"})
';
log_by_lua '
  metric_requests:inc(1, {ngx.var.server_name, ngx.var.status})
  metric_latency:observe(tonumber(ngx.var.request_time), {ngx.var.server_name})
';

# 创建 nginx-lua-prometheus
vim /etc/nginx/sites-available/nginx-lua-prometheus

server {
  listen 9145;
  location /metrics {
    content_by_lua '
      metric_connections:set(ngx.var.connections_reading, {"reading"})
      metric_connections:set(ngx.var.connections_waiting, {"waiting"})
      metric_connections:set(ngx.var.connections_writing, {"writing"})
      prometheus:collect()
';
  }
}

# 创建软链接 
cd /etc/nginx/sites-enabled/
ln -s ../sites-available/nginx-lua-prometheus

# 测试 Nginx 语法并 reload 测试 metrics
nginx -t
nginx -s reload
curl http://127.0.0.1:9145/metrics

# iptables rule for Prometheus Nginx 
-A INPUT -s xxx -p tcp --dport 9145 -j ACCEPT