Example - nginx-lua-prometheus
lua_shared_dict prometheus_metrics 10M;
lua_package_path "/path/to/nginx-lua-prometheus/?.lua;;";
init_worker_by_lua_block {
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_block {
metric_requests:inc(1, {ngx.var.server_name, ngx.var.status})
metric_latency:observe(tonumber(ngx.var.request_time), {ngx.var.server_name})
}