Update README and make config_key optional

README.md

@@ -8,13 +8,15 @@ Tourmaline is a (planned) agnostic, asynchronous and awesome installer framework
 Just run `cargo run -- help` or `trm help` for now.
 
 
-## Scripts
+## Distro Config
 
-Scripts for all supported distros are stored in the `config` folder of this repository.
+Scripts and config files for all supported distros are stored in the `config` folder of this repository.
 Each distro has its own folder with several subfolders corresponding to all integration tasks.
 
 ```
 <distro>
+  | distro.toml
+  | config.schema.json
   | <task>
       | up.nu
       | down.nu 
@@ -23,6 +25,68 @@ Each distro has its own folder with several subfolders corresponding to all inte
       | down.nu
 ```
 
+### Distro config
+
+The `distro.toml` file contains config options of the distro and allows one to define additional
+tasks to perform on install.
+The basic schema of this config file looks like this:
+
+```toml
+# Distro metadata
+[distro]
+
+# Name of the distro
+name = "Distro Name"
+
+# Website of the distro
+website = "https://mydistro.com"
+
+
+# Configuration of the OSConfig file
+[config]
+
+# Reference to the JSON Schema describing the config extension of that distro
+#[default: "config.schema.json"]
+schema = "config.schema.json"
+
+
+# Task-related configuration
+[tasks]
+
+# The key correspons to the name of the task on the file system.
+# In this case the scripts `custom-task/up.nu` and `custom-task/down.nu` must
+# exist in the distro's config folder
+[tasks.custom-task]
+
+# The key inside the extended config that is used to pass the config
+# value to this task
+# If this key is empty no value is passed to the task
+# [default: none]
+config_key = "enable_flatpak"
+
+# If set to true, the task will be skipped if the value of the task's config 
+# (indexed by config_key) is null or false. This setting is ignored when
+# no config_key is defined for this task
+# [default: false]
+skip_on_false = true
+
+# The order in which the task(s) should be executed. Note that
+# custom tasks alsways get executed after the base task.
+# [default: usize::MAX]
+order = 10
+```
+
+# Config Schema
+
+The config schema describing the extended OSConfig for that distro can be configured in the
+`distro.toml` and defaults to `config.schema.json`. 
+This file is a [JSON Schema](https://json-schema.org/) describing the additional fields
+required in the config. Make sure to mark required values as such so that the config
+get's properly validated.
+
+
+### Scripts
+
 The `up.nu` scripts contain the required steps to apply the change described by the task.
 This can include installing packages, creating configuration files and starting systemd units.
 

src/distro/distro_config.rs

@@ -39,7 +39,7 @@ pub struct OSConfigMetadata {
 #[derive(Clone, Debug, Deserialize)]
 pub struct TaskConfig {
     /// The name of the config field
-    pub config_key: String,
+    pub config_key: Option<String>,
 
     /// If the task should be skipped if the
     /// config value of that task is null

src/task/custom_task.rs

@@ -1,12 +1,14 @@
 use std::path::PathBuf;
 
+use embed_nu::IntoValue;
+
 use crate::{distro::OSConfig, error::AppResult};
 
 use super::{exec_builder::ExecBuilder, TaskTrait};
 
 #[derive(Clone, Debug)]
 pub struct CustomTask {
-    config_key: String,
+    config_key: Option<String>,
     up_script: PathBuf,
     down_script: PathBuf,
     skip_on_false: bool,
@@ -14,7 +16,12 @@ pub struct CustomTask {
 }
 
 impl CustomTask {
-    pub fn new(name: String, config_key: String, skip_on_false: bool, order: usize) -> Self {
+    pub fn new(
+        name: String,
+        config_key: Option<String>,
+        skip_on_false: bool,
+        order: usize,
+    ) -> Self {
         let base_path = PathBuf::from(name);
         Self {
             config_key,
@@ -29,9 +36,13 @@ impl CustomTask {
 impl TaskTrait for CustomTask {
     #[tracing::instrument(level = "trace", skip_all)]
     fn up(&self, config: &OSConfig) -> AppResult<Option<ExecBuilder>> {
-        let task_config = config.get_nu_value(&self.config_key)?;
+        let task_config = if let Some(key) = self.config_key.as_ref() {
+            config.get_nu_value(key)?
+        } else {
+            Option::<()>::None.into_value()
+        };
 
-        if self.skip_on_false && config_is_falsy(&task_config) {
+        if self.skip_on_false && self.config_key.is_some() && config_is_falsy(&task_config) {
             Ok(None)
         } else {
             Ok(Some(ExecBuilder {
@@ -44,9 +55,13 @@ impl TaskTrait for CustomTask {
 
     #[tracing::instrument(level = "trace", skip_all)]
     fn down(&self, config: &OSConfig) -> AppResult<Option<ExecBuilder>> {
-        let task_config = config.get_nu_value(&self.config_key)?;
+        let task_config = if let Some(key) = self.config_key.as_ref() {
+            config.get_nu_value(key)?
+        } else {
+            Option::<()>::None.into_value()
+        };
 
-        if self.skip_on_false && config_is_falsy(&task_config) {
+        if self.skip_on_false && self.config_key.is_some() && config_is_falsy(&task_config) {
             Ok(None)
         } else {
             Ok(Some(ExecBuilder {