# glances-rs

A Rust rewrite of [Glances](https://github.com/nicolargo/glances), the system
monitoring tool, targeting Linux.

This project is a drop-in replacement for the **standalone** Glances modes:

- curses-like terminal UI (`glances`)
- stdout modes: `--stdout`, `--stdout-csv`, `--stdout-json`
- `--fetch` (with the shipped templates), `--issue`, `--module-list`
- the same `glances.conf` configuration file (limits, thresholds, aliases,
  show/hide lists, per-plugin refresh, history, actions)
- compatible stats schemas and CLI flags for the implemented features

The following Python Glances features are intentionally **not** provided:
REST API, WebUI, MCP, client/server mode, discovery/browser, SNMP and
exporters.

## Status

| Area | Status |
| --- | --- |
| CLI (clap, drop-in flags) | done |
| Configuration (`glances.conf`) | done |
| Plugin model (limits, views, rates, MMM, history, events, actions) | done |
| Terminal UI (ratatui) | done |
| stdout / CSV / JSON / fetch / issue modes | done |
| Core plugins | cpu, percpu, mem, memswap, load, fs, network, diskio, sensors, irq, system, uptime, now, core, version, psutilversion, quicklook, processcount, processlist, programlist |
| Extended plugins | folders, amps, ports, raid, wifi, ip, containers (Docker) |
| Not ported yet | vms, gpu/npu/mpp, connections, smart, cloud, LXD containers |
| Python-specific flags | `--trace-malloc`, `--api-doc`, `--api-restful-doc` rejected with a clear error |

## Build and run

```console
$ cargo build --release
$ ./target/release/glances                 # terminal UI
$ ./target/release/glances --stdout-json cpu,mem,load
$ ./target/release/glances --fetch
```

## Differential testing

The `tools/parity.py` script compares the Rust implementation with the Python
reference implementation (the oracle) plugin by plugin: it runs both for a few
refreshes and diffs the flattened key sets and value types.

```console
$ python3 -m venv /tmp/opencode/glances-py
$ /tmp/opencode/glances-py/bin/pip install /path/to/python-glances
$ cargo build
$ python3 tools/parity.py            # all implemented plugins
$ python3 tools/parity.py cpu mem    # selected plugins
```

The containers plugin is compared against a live Docker daemon. Install the
Python extras (`pip install docker python-dateutil requests`) and have a
running container; the harness gives the plugin six refreshes because both
implementations need a warm-up sample before their rates are available. Use a
config with `[containers] all=True` to also compare stopped containers.

## Workspace layout

| Crate | Purpose |
| --- | --- |
| `glances-core` | plugin model, config, limits, history, events, filters, processes |
| `glances-plugins` | collectors, plugin registry and update engine |
| `glances-tui` | terminal UI (ratatui) |
| `glances-cli` | the `glances` binary, stdout modes and fetch renderer |

## License

Licensed under either of [Apache License, Version 2.0](LICENSE-APACHE) or
[MIT license](LICENSE-MIT) at your option.