brokkr-broker::utils::config_watcher

Rust

Configuration file watcher for hot-reload support.

This module provides functionality to watch for changes to the broker’s configuration file and trigger configuration reloads automatically.

Structs

struct ConfigWatcherConfig

pub

Derives: Debug, Clone

Configuration for the file watcher.

Fields

Name	Type	Description
config_file_path	String	Path to the configuration file to watch.
debounce_duration	Duration	Debounce duration to prevent rapid successive reloads.
enabled	bool	Whether the watcher is enabled.

Methods

from_​environment

pub

fn from_environment() -> Option<Self>

Creates a new ConfigWatcherConfig from environment variables.

Looks for BROKKR_CONFIG_FILE environment variable to determine the config file path. If not set, returns None (watcher disabled).

Source

    pub fn from_environment() -> Option<Self> {
        // Check if config file path is specified
        let config_file_path = match std::env::var("BROKKR_CONFIG_FILE") {
            Ok(path) if !path.is_empty() => path,
            _ => {
                debug!("BROKKR_CONFIG_FILE not set, config file watcher disabled");
                return None;
            }
        };

        // Verify the file exists
        if !Path::new(&config_file_path).exists() {
            warn!(
                "Config file '{}' does not exist, config file watcher disabled",
                config_file_path
            );
            return None;
        }

        // Check if watcher is explicitly disabled
        let enabled = std::env::var("BROKKR_CONFIG_WATCHER_ENABLED")
            .map(|v| v.to_lowercase() != "false" && v != "0")
            .unwrap_or(true);

        if !enabled {
            info!("Config file watcher explicitly disabled via environment variable");
            return None;
        }

        // Get debounce duration from environment (in seconds)
        let debounce_secs = std::env::var("BROKKR_CONFIG_WATCHER_DEBOUNCE_SECONDS")
            .ok()
            .and_then(|v| v.parse().ok())
            .unwrap_or(5);

        Some(Self {
            config_file_path,
            debounce_duration: Duration::from_secs(debounce_secs),
            enabled: true,
        })
    }

Functions

fn start_​config_​watcher

pub

fn start_config_watcher(
    config: ReloadableConfig,
    watcher_config: ConfigWatcherConfig,
) -> Option<tokio::task::JoinHandle<()>>

Starts the configuration file watcher as a background task.

This function spawns a tokio task that watches for changes to the specified configuration file and triggers configuration reloads with debouncing.

Parameters:

Name	Type	Description
config	ReloadableConfig	The ReloadableConfig instance to reload on changes.
watcher_config	ConfigWatcherConfig	Configuration for the watcher.

Returns:

A handle to the spawned task, or None if the watcher couldn’t be started.

Source

pub fn start_config_watcher(
    config: ReloadableConfig,
    watcher_config: ConfigWatcherConfig,
) -> Option<tokio::task::JoinHandle<()>> {
    if !watcher_config.enabled {
        info!("Config file watcher is disabled");
        return None;
    }

    info!(
        "Starting config file watcher for '{}' with {}s debounce",
        watcher_config.config_file_path,
        watcher_config.debounce_duration.as_secs()
    );

    let handle = tokio::spawn(async move {
        if let Err(e) = run_config_watcher(config, watcher_config).await {
            error!("Config file watcher error: {}", e);
        }
    });

    Some(handle)
}