# sysinfod

**Repository Path**: lanceye/sysinfod

## Basic Information

- **Project Name**: sysinfod
- **Description**: Linux 系统信息监控守护进程。通过读取 `/proc` 文件系统和系统调用（`sysinfo()`、`statfs()` 等）采集 CPU、内存、磁盘、网络、进程等指标，通过嵌入式 HTTP 服务器（libevent）提供 REST API，并定时推送 JSON 数据到远程监控平台。

- **Primary Language**: C
- **License**: MulanPSL-1.0
- **Default Branch**: master
- **Homepage**: None
- **GVP Project**: No

## Statistics

- **Stars**: 0
- **Forks**: 0
- **Created**: 2026-07-04
- **Last Updated**: 2026-07-04

## Categories & Tags

**Categories**: Uncategorized

**Tags**: None

## README

# sysinfod

A Linux system information monitoring daemon. It collects CPU, memory, disk, network, and process metrics by reading `/proc` filesystem and system calls (`sysinfo()`, `statfs()`, etc.), serves them via an embedded HTTP server (libevent) with REST API endpoints, and periodically pushes JSON data to a remote monitoring platform.

## Features

- **CPU**: usage percentage, core count, system boot time, OS distribution name/version
- **Memory**: total/free/used physical RAM and swap, process count, memory unit size
- **Disk**: mounted filesystem list (device, mount point, type, block size, total/free/available blocks, free inodes)
- **Network**: total bytes received/sent, TCP connection details (IP/port/state/queue/timer, 22 fields)
- **Process**: list of running processes (PID, command, path, user, memory usage, process name)
- **HTTP API**: 7 REST endpoints + remote push
- **Remote Push**: periodically POST aggregated JSON to remote server

## Dependencies

- libevent (`libevent`, `libevent_core`, `libevent_pthreads`)
- pthreads
- CMake >= 3.15
- Linux only

## Build

```bash
mkdir build && cd build
cmake ..
make
```

Place `config.json` in the same directory as the executable (or the current working directory at runtime).

## Configuration

At startup, the daemon reads `config.json`. If the file is missing or malformed, hardcoded defaults are used.

**Example `config.json`:**

```json
{
    "DEFAULT_PORT": 9801,
    "PULL_SYS_INFO_INTERVAL": 10,
    "SERVER_URL": "http://172.16.132.7/monitor/server/info",
    "TOKEN": "CHANGE_THIS_TO_A_STRONG_TOKEN"
}
```

| Key | Default | Description |
|-----|---------|-------------|
| `DEFAULT_PORT` | `9801` | Local HTTP monitoring port (daemon mode) |
| `PULL_SYS_INFO_INTERVAL` | `10` | Collection interval (seconds) |
| `SERVER_URL` | `http://172.16.132.7/monitor/server/info` | Remote push URL |
| `TOKEN` | `CHANGE_THIS_TO_A_STRONG_TOKEN` | HTTP API authentication token (recommended >= 8 chars) |

> **Security**: A warning is printed at startup if the default token is detected. Token comparison uses constant-time comparison to prevent timing side-channel attacks. Communication is over plain HTTP — avoid using on public networks.

## Run Modes

### Push-Only Mode (Default)

```bash
./sysinfod
```

The program enters an infinite loop that only performs remote pushes; **the HTTP API server is NOT started**.

### Daemon Mode

```bash
./sysinfod -d
# or
./sysinfod --daemon
```

The program will:
- Double-fork to detach from the terminal
- Use `/tmp/sysinfod` lockfile for singleton enforcement
- Redirect stdin/stdout/stderr to `/dev/null`
- Start a background thread for periodic push; the main thread starts the HTTP API server
- Register `SIGINT`/`SIGTERM` handlers for graceful shutdown

## HTTP API Endpoints

All endpoints bind to `0.0.0.0:port`. With the exception of the 404 fallback, **every endpoint requires a `TOKEN` request header for authentication** (value configured in `config.json`).

**Example request:**
```bash
curl -H "TOKEN: your_token" http://localhost:9801/cpu
```

| Method | Path | Description | Response |
|--------|------|-------------|----------|
| GET | `/cpu` | CPU usage percentage (1s sample) | `{"usage":"<percent>"}` |
| GET | `/cores` | CPU core count | `{"cores":<int>}` |
| GET | `/start_time` | System boot time | `{"start_time":"YYYY-MM-DD HH:MM:SS"}` |
| GET | `/mem` | Memory & swap stats | `{"totalram":"...","freeram":"...","totalswap":"...","freeswap":"...","procs":"...","mem_unit":"..."}` |
| GET | `/disk` | Mounted filesystems | JSON array |
| GET | `/process` | Running processes | JSON array |
| GET | `/net_info` | Total bytes sent/received | `{"rec":<bytes_recv>,"rev":<bytes_sent>}` |
| — | Remote push | POST aggregated data to `SERVER_URL` | See below |

## Remote Push

- **Method**: HTTP POST
- **URL**: `SERVER_URL` from `config.json`
- **Interval**: `PULL_SYS_INFO_INTERVAL` from `config.json` (seconds)
- **Connection timeout**: 5 seconds

### Push JSON Format

```json
{
  "start_time": "<boot time>",
  "os_name_version": "<distro> @x86_64",
  "cpu_usage": "<percent>",
  "process": "<process JSON string>",
  "disk_info": "<disk JSON string>",
  "cores": "<count>",
  "mem_usage": "<memory JSON string>",
  "net_info": "{\"rev\":<bytes_sent>,\"send\":<bytes_recv>,\"tcp_num\":<int>}",
  "connections": "<TCP connections JSON string>"
}
```

> All values are strings; nested JSON objects are double-encoded (stringified JSON).

## Data Sources

| System file/call | Module | Data collected |
|----------------|--------|----------------|
| `/proc/stat` | CPU | Cumulative CPU ticks |
| `/etc/os-release`, `/etc/*-release` | CPU | Distribution name/version |
| `sysinfo()` | CPU/Memory | Uptime, memory/swap stats |
| `uname()` | CPU | Kernel version, architecture |
| `/proc/mounts` + `statfs()` | Disk | Mount points, block/inode info |
| `/proc/net/dev` | Network | Interface bytes sent/received |
| `/proc/net/tcp` | Network | TCP connection details (22 fields) |
| `/proc/<pid>/{cmdline,exe,status}` | Process | Command, path, memory, user |

## Known Issues

1. The `/cpu` endpoint blocks for ~1 second to sample CPU usage
2. The `/process` endpoint iterates over all processes and may be slow on busy systems
3. `/etc/os-release` parsing relies on `PRETTY_NAME`/`NAME`/`VERSION` standard fields; non-standard entries fall back to `uname()`
4. Communication is over plain HTTP — tokens and system data are vulnerable to MITM attacks; use only on trusted internal networks

## Acknowledgements

This project is based on [sysinfod](https://gitee.com/28250164/sysinfod). Thanks to the original author.

## License

This project is released under the GNU General Public License v3.0.