2025-12-31 17:06:31 -05:00

112 lines
3.0 KiB
Markdown

# Now Playing Logger Plugin (Python)
A Python example plugin that demonstrates the **Scheduler** and **SubsonicAPI** host services by periodically logging what is currently playing in Navidrome.
## Features
- Uses `scheduler_schedulerecurring` host function to set up a recurring task
- Uses `subsonicapi_call` host function to query the `getNowPlaying` API
- Configurable cron expression and user via plugin config
- Demonstrates Python host function imports using `@extism.import_fn`
## Prerequisites
- [extism-py](https://github.com/extism/python-pdk) - Python PDK compiler
```bash
curl -Ls https://raw.githubusercontent.com/extism/python-pdk/main/install.sh | bash
```
> **Note:** `extism-py` requires [Binaryen](https://github.com/WebAssembly/binaryen/) (`wasm-merge`, `wasm-opt`) to be installed.
## Building
From the `plugins/examples` directory:
```bash
make nowplaying-py.ndp
```
Or directly:
```bash
extism-py plugin/__init__.py -o plugin.wasm
zip -j nowplaying-py.ndp manifest.json plugin.wasm
```
## Installation
1. Copy `nowplaying-py.ndp` to your Navidrome plugins folder
2. Enable plugins in `navidrome.toml`:
```toml
[Plugins]
Enabled = true
Folder = "/path/to/plugins"
```
3. Configure the plugin in the UI (Settings → Plugins → nowplaying-py)
## Configuration
| Key | Description | Default |
|--------|-------------------------------------|---------------|
| `cron` | Cron expression for check frequency | `*/1 * * * *` |
| `user` | Navidrome user for SubsonicAPI | `admin` |
## Testing
Test the manifest:
```bash
extism call nowplaying-py.wasm nd_manifest --wasi
```
## Output
When running, the plugin logs messages like:
```
🎵 john is playing: Pink Floyd - Comfortably Numb (The Wall)
🎵 jane is playing: Radiohead - Paranoid Android (OK Computer)
```
Or when no one is playing:
```
🎵 No users currently playing music
```
## How It Works
1. **Initialization (`nd_on_init`)**: Reads the cron expression from config and schedules a recurring task using the Scheduler host service.
2. **Callback (`nd_scheduler_callback`)**: When the scheduled task fires, calls the SubsonicAPI `getNowPlaying` endpoint and logs the results.
## Host Function Usage (Python)
This plugin demonstrates how to call Navidrome host functions from Python:
```python
import extism
import json
# Import the host function
@extism.import_fn("extism:host/user", "subsonicapi_call")
def _subsonicapi_call(offset: int) -> int:
"""Raw host function - returns memory offset."""
...
# Wrapper for JSON marshalling
def subsonicapi_call(uri: str) -> dict:
request = {"uri": uri}
request_bytes = json.dumps(request).encode('utf-8')
request_mem = extism.memory.alloc(request_bytes)
response_offset = _subsonicapi_call(request_mem.offset)
response_mem = extism.memory.find(response_offset)
response = json.loads(extism.memory.string(response_mem))
if response.get("error"):
raise Exception(response["error"])
return json.loads(response.get("responseJSON", "{}"))
```