feat: Simplify state setup using enum and add documentation

Signed-off-by: David Runge <[email protected]>

dist/caterpillar.toml

@@ -1,9 +1,19 @@
 # SPDX-FileCopyrightText: 2023 David Runge <[email protected]>
 # SPDX-License-Identifier: LGPL-3.0-or-later
 
+# This configuration file documents the built-in defaults for caterpillar
+
+# Run non-interactively on first start.
+# This automatically searches for an update, installs a matching update if found and reboots.
 autorun = true
+
+# The file extension to search for at the top-level or in an override_dir on a mounted filesystem.
 bundle_extension = "raucb"
+
+# The regular expression used to match for block devices discovered by udisks2 over D-Bus.
 device_regex = "^/org/freedesktop/UDisks2/block_devices/sd[a-z]{1}[1-9]{1}[0-9]*?$"
-interactive_on_first_run = false
+
+# The name of a directory in which override updates are searched for.
+# Valid updates in this directory have precedence over those found in the top-level filesystem.
+# This is useful for downgrade scenarios.
 override_dir = "override"
-reboot = true

src/config.rs

@@ -4,15 +4,15 @@ use config::{Config, ConfigError, File};
 
 pub const DEVICE_REGEX: &str = "^/org/freedesktop/UDisks2/block_devices/sd[a-z]{1}[1-9]{1}[0-9]*?$";
 
+/// Read the configuration for the application
+///
+/// This uses built-in defaults, which can be overridden with an optional configuration file found in /etc/caterpillar/caterpillar.toml
 pub async fn read_config() -> Result<Config, ConfigError> {
     Config::builder()
         .set_default("autorun", true)?
-        // by default we want to match any block device
         .set_default("bundle_extension", "raucb")?
         .set_default("device_regex", DEVICE_REGEX)?
-        .set_default("interactive_on_first_run", true)?
         .set_default("override_dir", "override")?
-        .set_default("reboot", true)?
         .add_source(File::with_name("/etc/caterpillar/caterpillar").required(false))
         .add_source(config::Environment::with_prefix("CATERPILLAR"))
         .build()