ngx_http_monitoring_module

ngx_http_monitoring_module is a Linux-only dynamic Nginx HTTP module for live server monitoring, JSON APIs, Server-Sent Events, and an embedded dashboard.

Features

• Dynamic module build for Nginx 1.24+
• Shared-memory metrics across workers
• Atomic request counters and bounded top-N tables
• Timer-based /proc collectors with cached snapshots
• JSON REST API under /monitor/api
• Embedded dark dashboard at /monitor
• Server-Sent Events stream at /monitor/live
• Prometheus text endpoint at /monitor/metrics
• ACL, optional basic auth, optional API token, CORS, and simple global API rate limiting
• Historical ring buffer with configurable retention and resolution

Build

Install Nginx build prerequisites and use an Nginx source tree configured similarly to the Nginx binary you will load the module into.

NGINX_SRC=/usr/local/src/nginx-1.24.0 make module

Recommended configure options:

NGINX_CONFIGURE_ARGS="--with-compat --with-http_ssl_module --with-http_stub_status_module" \
NGINX_SRC=/usr/local/src/nginx-1.24.0 make module

The compiled module is written to:

build/ngx_http_monitoring_module.so

The source avoids glibc-only mount parsing APIs such as getmntent() and parses /proc/mounts directly, which keeps the collectors portable across Linux libc implementations that expose the required /proc, statvfs(), and getifaddrs() interfaces.

Docker Image

A Dockerized Nginx image is available in dockerized:

docker build -f dockerized/Dockerfile -t ngx-http-monitoring-module:local .
docker run --rm -p 8080:8080 ngx-http-monitoring-module:local

Then open:

http://127.0.0.1:8080/monitor

Agent Skill

A reusable Codex skill for clients and agents is available at skills/ngx-http-monitoring-client/SKILL.md. It covers JSON, SSE, Prometheus, API token usage, and Nginx Basic Auth.

GitHub Releases

The repository includes a manual GitHub Actions workflow at .github/workflows/release.yml that computes the next vMAJOR.MINOR.PATCH tag, builds Ubuntu/Debian distro-specific module packages, keeps generic nginx.org source-version tarballs, validates the artifacts, pushes the tag, and publishes the release. Production installs on Ubuntu/Debian should prefer the generated .deb packages because they depend on the matching distro Nginx ABI and exact Nginx binary package revision. See docs/RELEASES.md for release asset format and compatibility notes.

CI Tests

.github/workflows/test.yml runs on pushes and pull requests. It builds Nginx and the dynamic module against common upstream Nginx versions as a broad source sanity check, and also builds distro packages against Ubuntu/Debian packaged Nginx on amd64. Both paths run nginx -t, start Nginx, and check the dashboard, JSON API, health, Prometheus, and SSE routes.

Load The Module

Load it from nginx.conf:

load_module modules/ngx_http_monitoring_module.so;

Minimal Configuration

http {
    monitor_refresh_interval 1s;
    monitor_history 5m;
    monitor_resolution 1s;

    server {
        listen 8080;

        location /monitor {
            monitor on;
            monitor_allow 127.0.0.1/32;
            monitor_deny all;
        }
    }
}

Open:

http://127.0.0.1:8080/monitor

After Nginx is running, run endpoint smoke checks:

BASE_URL=http://127.0.0.1:8080 sh scripts/smoke.sh

Endpoints

• GET /monitor - embedded dashboard
• GET /monitor/api - full JSON document
• GET /monitor/api/system - CPU, load, memory, swap, uptime
• GET /monitor/api/nginx - Nginx connection/request/worker metrics
• GET /monitor/api/network - interfaces and traffic counters
• GET /monitor/api/disk - block device and filesystem counters
• GET /monitor/api/processes - process count, TCP/socket stats, workers
• GET /monitor/api/upstreams - observed upstream peer stats
• GET /monitor/api/connections - connection and SSE counters
• GET /monitor/api/requests - status, methods, histograms, top URLs, user agents
• GET /monitor/live - SSE metrics stream
• GET /monitor/metrics - Prometheus-compatible text metrics
• GET /monitor/health - lightweight health JSON

Notes

The module is intentionally dependency-free at runtime. System data is collected by worker timers from Linux /proc, statvfs(), and getifaddrs(), then served from shared memory. API requests never parse /proc directly.

For exact active/reading/writing/waiting connection counters, build Nginx with --with-http_stub_status_module.