Merge branch 'feature/add_config_exploration' into feature/add_tedge_api_only

9 files changed, 835 insertions, 107 deletions

diff --git a/Cargo.lock b/Cargo.lock
index b0cec5fc..6a8277f5 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -72,9 +72,9 @@ checksum = "48ad219abc0c06ca788aface2e3a1970587e3413ab70acd20e54b6ec524c1f8f"
 dependencies = [
  "argh_shared",
  "heck",
- "proc-macro2 1.0.32",
- "quote 1.0.10",
- "syn 1.0.82",
+ "proc-macro2 1.0.38",
+ "quote 1.0.18",
+ "syn 1.0.93",
 ]
 
 [[package]]
@@ -168,9 +168,9 @@ version = "0.3.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "648ed8c8d2ce5409ccd57453d9d1b214b342a0d69376a6feda1fd6cae3299308"
 dependencies = [
- "proc-macro2 1.0.32",
- "quote 1.0.10",
- "syn 1.0.82",
+ "proc-macro2 1.0.38",
+ "quote 1.0.18",
+ "syn 1.0.93",
 ]
 
 [[package]]
@@ -179,9 +179,9 @@ version = "0.1.52"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "061a7acccaa286c011ddc30970520b98fa40e00c9d644633fb26b5fc63a265e3"
 dependencies = [
- "proc-macro2 1.0.32",
- "quote 1.0.10",
- "syn 1.0.82",
+ "proc-macro2 1.0.38",
+ "quote 1.0.18",
+ "syn 1.0.93",
 ]
 
 [[package]]
@@ -675,8 +675,8 @@ version = "0.1.21"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ccc0a48a9b826acdf4028595adc9db92caea352f7af011a3034acd172a52a0aa"
 dependencies = [
- "quote 1.0.10",
- "syn 1.0.82",
+ "quote 1.0.18",
+ "syn 1.0.93",
 ]
 
 [[package]]
@@ -693,7 +693,7 @@ checksum = "c73af209b6a5dc8ca7cbaba720732304792cddc933cfea3d74509c2b1ef2f436"
 dependencies = [
  "num-bigint 0.4.3",
  "num-traits",
- "syn 1.0.82",
+ "syn 1.0.93",
 ]
 
 [[package]]
@@ -976,9 +976,9 @@ version = "0.3.21"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "33c1e13800337f4d4d7a316bf45a567dbcb6ffe087f16424852d97e97a91f512"
 dependencies = [
- "proc-macro2 1.0.32",
- "quote 1.0.10",
- "syn 1.0.82",
+ "proc-macro2 1.0.38",
+ "quote 1.0.18",
+ "syn 1.0.93",
 ]
 
 [[package]]
@@ -1404,9 +1404,9 @@ version = "4.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "45a95a48d0bc28f9af628286e8a4da09f96f34a97744a2e9a5a4db9814ad527d"
 dependencies = [
- "proc-macro2 1.0.32",
- "quote 1.0.10",
- "syn 1.0.82",
+ "proc-macro2 1.0.38",
+ "quote 1.0.18",
+ "syn 1.0.93",
 ]
 
 [[package]]
@@ -1508,9 +1508,9 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e7e25b214433f669161f414959594216d8e6ba83b6679d3db96899c0b4639033"
 dependencies = [
  "cfg-if 1.0.0",
- "proc-macro2 1.0.32",
- "quote 1.0.10",
- "syn 1.0.82",
+ "proc-macro2 1.0.38",
+ "quote 1.0.18",
+ "syn 1.0.93",
 ]
 
 [[package]]
@@ -1874,9 +1874,9 @@ version = "1.0.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "6e8fe8163d14ce7f0cdac2e040116f22eac817edabff0be91e8aff7e9accf389"
 dependencies = [
- "proc-macro2 1.0.32",
- "quote 1.0.10",
- "syn 1.0.82",
+ "proc-macro2 1.0.38",
+ "quote 1.0.18",
+ "syn 1.0.93",
 ]
 
 [[package]]
@@ -2018,9 +2018,9 @@ dependencies = [
 
 [[package]]
 name = "pretty_assertions"
-version = "1.0.0"
+version = "1.2.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ec0cfe1b2403f172ba0f234e500906ee0a3e493fb81092dac23ebefe129301cc"
+checksum = "c89f989ac94207d048d92db058e4f6ec7342b0971fc58d1271ca148b799b3563"
 dependencies = [
  "ansi_term",
  "ctor",
@@ -2045,9 +2045,9 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "da25490ff9892aab3fcf7c36f08cfb902dd3e71ca0f9f9517bea02a73a5ce38c"
 dependencies = [
  "proc-macro-error-attr",
- "proc-macro2 1.0.32",
- "quote 1.0.10",
- "syn 1.0.82",
+ "proc-macro2 1.0.38",
+ "quote 1.0.18",
+ "syn 1.0.93",
  "version_check",
 ]
 
@@ -2057,8 +2057,8 @@ version = "1.0.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a1be40180e52ecc98ad80b184934baf3d0d29f979574e439af5a55274b35f869"
 dependencies = [
- "proc-macro2 1.0.32",
- "quote 1.0.10",
+ "proc-macro2 1.0.38",
+ "quote 1.0.18",
  "version_check",
 ]
 
@@ -2073,9 +2073,9 @@ dependencies = [
 
 [[package]]
 name = "proc-macro2"
-version = "1.0.32"
+version = "1.0.38"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ba508cc11742c0dc5c1659771673afbab7a0efab23aa17e854cbab0837ed0b43"
+checksum = "9027b48e9d4c9175fa2218adf3557f91c1137021739951d4932f5f8268ac48aa"
 dependencies = [
  "unicode-xid 0.2.2",
 ]
@@ -2123,11 +2123,11 @@ dependencies = [
 
 [[package]]
 name = "quote"
-version = "1.0.10"
+version = "1.0.18"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "38bc8cc6a5f2e3655e0899c1b848643b2562f853f114bfec7be120678e3ace05"
+checksum = "a1feb54ed693b93a84e14094943b84b7c4eae204c512b7ccb95ab0c66d278ad1"
 dependencies = [
- "proc-macro2 1.0.32",
+ "proc-macro2 1.0.38",
 ]
 
 [[package]]
@@ -2580,9 +2580,9 @@ version = "1.0.136"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "08597e7152fcd306f41838ed3e37be9eaeed2b61c42e2117266a554fab4662f9"
 dependencies = [
- "proc-macro2 1.0.32",
- "quote 1.0.10",
- "syn 1.0.82",
+ "proc-macro2 1.0.38",
+ "quote 1.0.18",
+ "syn 1.0.93",
 ]
 
 [[package]]
@@ -2625,9 +2625,9 @@ version = "0.5.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b2acd6defeddb41eb60bb468f8825d0cfd0c2a76bc03bfd235b6a1dc4f6a1ad5"
 dependencies = [
- "proc-macro2 1.0.32",
- "quote 1.0.10",
- "syn 1.0.82",
+ "proc-macro2 1.0.38",
+ "quote 1.0.18",
+ "syn 1.0.93",
 ]
 
 [[package]]
@@ -2747,9 +2747,9 @@ checksum = "dcb5ae327f9cc13b68763b5749770cb9e048a99bd9dfdfa58d0cf05d5f64afe0"
 dependencies = [
  "heck",
  "proc-macro-error",
- "proc-macro2 1.0.32",
- "quote 1.0.10",
- "syn 1.0.82",
+ "proc-macro2 1.0.38",
+ "quote 1.0.18",
+ "syn 1.0.93",
 ]
 
 [[package]]
@@ -2765,12 +2765,12 @@ dependencies = [
 
 [[package]]
 name = "syn"
-version = "1.0.82"
+version = "1.0.93"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8daf5dd0bb60cbd4137b1b587d2fc0ae729bc07cf01cd70b36a1ed5ade3b9d59"
+checksum = "04066589568b72ec65f42d65a1a52436e954b168773148893c020269563decf2"
 dependencies = [
- "proc-macro2 1.0.32",
- "quote 1.0.10",
+ "proc-macro2 1.0.38",
+ "quote 1.0.18",
  "unicode-xid 0.2.2",
 ]
 
@@ -2861,8 +2861,10 @@ dependencies = [
  "miette",
  "nu-ansi-term",
  "pretty",
+ "pretty_assertions",
  "serde",
  "static_assertions",
+ "tedge_config_derive",
  "termcolor",
  "termimad",
  "thiserror",
@@ -2903,6 +2905,16 @@ dependencies = [
 ]
 
 [[package]]
+name = "tedge_config_derive"
+version = "0.1.0"
+dependencies = [
+ "proc-macro-error",
+ "proc-macro2 1.0.38",
+ "quote 1.0.18",
+ "syn 1.0.93",
+]
+
+[[package]]
 name = "tedge_dummy_plugin"
 version = "0.5.2"
 dependencies = [
@@ -3021,9 +3033,9 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c7cad0a06f9a61e94355aa3b3dc92d85ab9c83406722b1ca5e918d4297c12c23"
 dependencies = [
  "cfg-if 1.0.0",
- "proc-macro2 1.0.32",
- "quote 1.0.10",
- "syn 1.0.82",
+ "proc-macro2 1.0.38",
+ "quote 1.0.18",
+ "syn 1.0.93",
  "version_check",
 ]
 
@@ -3072,9 +3084,9 @@ version = "1.0.30"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "aa32fd3f627f367fe16f893e2597ae3c05020f8bba2666a4e6ea73d377e5714b"
 dependencies = [
- "proc-macro2 1.0.32",
- "quote 1.0.10",
- "syn 1.0.82",
+ "proc-macro2 1.0.38",
+ "quote 1.0.18",
+ "syn 1.0.93",
 ]
 
 [[package]]
@@ -3165,9 +3177,9 @@ version = "1.7.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "b557f72f448c511a979e2564e55d74e6c4432fc96ff4f6241bc6bded342643b7"
 dependencies = [
- "proc-macro2 1.0.32",
- "quote 1.0.10",
- "syn 1.0.82",
+ "proc-macro2 1.0.38",
+ "quote 1.0.18",
+ "syn 1.0.93",
 ]
 
 [[package]]
@@ -3291,9 +3303,9 @@ version = "0.1.18"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "f4f480b8f81512e825f337ad51e94c1eb5d3bbdf2b363dcd01e2b19a9ffe3f8e"
 dependencies = [
- "proc-macro2 1.0.32",
- "quote 1.0.10",
- "syn 1.0.82",
+ "proc-macro2 1.0.38",
+ "quote 1.0.18",
+ "syn 1.0.93",
 ]
 
 [[package]]
@@ -3589,9 +3601,9 @@ dependencies = [
  "bumpalo",
  "lazy_static",
  "log",
- "proc-macro2 1.0.32",
- "quote 1.0.10",
- "syn 1.0.82",
+ "proc-macro2 1.0.38",
+ "quote 1.0.18",
+ "syn 1.0.93",
  "wasm-bindgen-shared",
 ]
 
@@ -3613,7 +3625,7 @@ version = "0.2.79"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "2f4203d69e40a52ee523b2529a773d5ffc1dc0071801c87b3d270b471b80ed01"
 dependencies = [
- "quote 1.0.10",
+ "quote 1.0.18",
  "wasm-bindgen-macro-support",
 ]
 
@@ -3623,9 +3635,9 @@ version = "0.2.79"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "bfa8a30d46208db204854cadbb5d4baf5fcf8071ba5bf48190c3e59937962ebc"
 dependencies = [
- "proc-macro2 1.0.32",
- "quote 1.0.10",
- "syn 1.0.82",
+ "proc-macro2 1.0.38",
+ "quote 1.0.18",
+ "syn 1.0.93",
  "wasm-bindgen-backend",
  "wasm-bindgen-shared",
 ]
diff --git a/Cargo.toml b/Cargo.toml
index 0bd9467e..bf58964b 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -3,6 +3,7 @@
 members = [
     "crates/common/*",
     "crates/core/*",
+    "crates/core/tedge_api/tedge_config_derive",
     "crates/tests/*",
     "plugins/tedge_apt_plugin",
     "plugins/tedge_dummy_plugin",
diff --git a/crates/core/tedge_api/Cargo.toml b/crates/core/tedge_api/Cargo.toml
index 7fdf5508..619e769e 100644
--- a/crates/core/tedge_api/Cargo.toml
+++ b/crates/core/tedge_api/Cargo.toml
@@ -19,7 +19,9 @@ pretty = { version = "0.11.3", features = ["termcolor"] }
 termcolor = "1.1.3"
 termimad = "0.20.1"
 nu-ansi-term = "0.45.1"
+tedge_config_derive = { version = "0.1.0", path = "tedge_config_derive" }
 
 [dev-dependencies]
+pretty_assertions = "1.2.1"
 static_assertions = "1.1.0"
 tokio = { version = "1.16.1", features = ["full"] }
diff --git a/crates/core/tedge_api/examples/print_config.rs b/crates/core/tedge_api/examples/print_config.rs
index 5ee6458e..ba6e7a6b 100644
--- a/crates/core/tedge_api/examples/print_config.rs
+++ b/crates/core/tedge_api/examples/print_config.rs
@@ -2,7 +2,10 @@ use std::collections::HashMap;
 
 use nu_ansi_term::Color;
 use pretty::Arena;
-use tedge_api::config::{AsConfig, ConfigDescription, ConfigKind};
+use tedge_api::{
+    config::{AsConfig, ConfigDescription, ConfigKind},
+    Config,
+};
 struct Port(u64);
 
 impl AsConfig for Port {
@@ -21,7 +24,7 @@ impl AsConfig for VHost {
     fn as_config() -> ConfigDescription {
         ConfigDescription::new(
             String::from("VHost"),
-            ConfigKind::Struct(HashMap::from([(String::from("name"), String::as_config())])),
+            ConfigKind::Struct(vec![("name", None, String::as_config())]),
             Some("A virtual host definition"),
         )
     }
@@ -47,12 +50,12 @@ fn main() {
 
     let doc = ConfigDescription::new(
             String::from("ServerConfig"),
-            ConfigKind::Struct(HashMap::from([
-                (String::from("port"), Port::as_config()),
-                (String::from("interface"), String::as_config()),
-                (String::from("virtual_hosts"), Vec::<VHost>::as_config()),
-                (String::from("headers"), HashMap::<String, String>::as_config()),
-            ])),
+            ConfigKind::Struct(vec![
+                ("port", None, Port::as_config()),
+                ("interface", None, String::as_config()),
+                ("virtual_hosts", None, Vec::<VHost>::as_config()),
+                ("headers", None, HashMap::<String, String>::as_config()),
+            ]),
             Some("Specify how the server should be started\n\n## Note\n\nThis is a reallly really loooooooooooooooooong loooooooooooooooooooong new *line*."),
         );
     let rendered_doc = doc.as_terminal_doc(&arena);
@@ -76,5 +79,71 @@ fn main() {
     );
     println!("------- Output for ServerConfig");
     println!("{}", output);
+    let arena = Arena::new();
+
+    #[derive(Config)]
+    #[config(tag = "type")]
+    /// An Nginx virtual host
+    ///
+    /// # Note
+    ///
+    /// This is an example and as such is nonsense
+    enum NginxVHost {
+        /// A simple host consisting of a string
+        Simple(String),
+        /// A more complex host that can also specify its port
+        Complex {
+            /// the name of the VHost
+            name: String,
+            port: Port,
+        },
+        UndocumentedComplex {
+            num: u16,
+            foo: f32,
+        },
+    }
+
+    #[derive(Config)]
+    #[config(untagged)]
+    enum DebugLevel {
+        /// Enables debug output
+        ///
+        /// And info of course
+        Debug,
+        /// Only pertinent information will be logged
+        Info,
+        /// A custom debug level
+        Custom(String),
+    }
+
+    #[derive(Config)]
+    struct NginxConfig {
+        vhosts: Vec<NginxVHost>,
+        debug_level: DebugLevel,
+        allow_priv_ports: bool,
+    }
+
+    let doc = NginxConfig::as_config();
+    let rendered_doc = doc.as_terminal_doc(&arena);
+
+    let mut output = String::new();
+
+    rendered_doc.render_fmt(80, &mut output).unwrap();
+
+    println!("------- Output for NginxConfig");
+    println!(
+        "Configuration for {} plugin kinds",
+        Color::White.bold().paint(doc.name())
+    );
+    println!(
+        "{}",
+        Color::White.dimmed().bold().paint(format!(
+            "=================={}=============",
+            std::iter::repeat('=')
+                .take(doc.name().len())
+                .collect::<String>()
+        ))
+    );
+    println!("{}", output);
     println!("-------");
 }
diff --git a/crates/core/tedge_api/src/config.rs b/crates/core/tedge_api/src/config.rs
index 7357b497..90bee595 100644
--- a/crates/core/tedge_api/src/config.rs
+++ b/crates/core/tedge_api/src/config.rs
@@ -6,7 +6,7 @@ use serde::Serialize;
 use termimad::MadSkin;
 
 /// Generic config that represents what kind of config a plugin wishes to accept
-#[derive(Debug, Serialize)]
+#[derive(Debug, Serialize, PartialEq)]
 pub struct ConfigDescription {
     name: String,
     kind: ConfigKind,
@@ -46,8 +46,28 @@ impl ConfigDescription {
     }
 }
 
+/// How an enum is represented
+#[derive(Debug, Serialize, PartialEq)]
+pub enum EnumVariantRepresentation {
+    /// The enum is represented by a string
+    ///
+    /// This is the case with unit variants for example
+    String(&'static str),
+    /// The enum is represented by the value presented here
+    Wrapped(Box<ConfigDescription>),
+}
+
+/// The kind of enum tagging used by the [`ConfigKind`]
+#[derive(Debug, Serialize, PartialEq)]
+pub enum ConfigEnumKind {
+    /// An internal tag with the given tag name
+    Tagged(&'static str),
+    /// An untagged enum variant
+    Untagged,
+}
+
 /// The specific kind a [`Config`] represents
-#[derive(Debug, Serialize)]
+#[derive(Debug, Serialize, PartialEq)]
 pub enum ConfigKind {
     /// Config represents a boolean `true`/`false`
     Bool,
@@ -70,18 +90,37 @@ pub enum ConfigKind {
     /// Config represents a string
     String,
 
+    /// Wrap another config
+    ///
+    /// This is particularly useful if you want to restrict another kind. The common example is a
+    /// `Port` config object which is represented as a `u16` but with an explanation of what it is
+    /// meant to represent.
+    Wrapped(Box<ConfigDescription>),
+
     /// Config represents an array of values of the given [`ConfigKind`]
     Array(Box<ConfigDescription>),
 
-    /// Config represents a map of different configurations
-    Struct(HashMap<String, ConfigDescription>),
-
     /// Config represents a hashmap of named configurations of the same type
     ///
     /// # Note
     ///
     /// The key is always a [`String`] so this only holds the value config
     HashMap(Box<ConfigDescription>),
+
+    /// Config represents a map of different configurations
+    ///
+    /// The tuple represent `(field_name, documentation, config_description)`
+    Struct(Vec<(&'static str, Option<&'static str>, ConfigDescription)>),
+
+    /// Config represents multiple choice of configurations
+    Enum(
+        ConfigEnumKind,
+        Vec<(
+            &'static str,
+            Option<&'static str>,
+            EnumVariantRepresentation,
+        )>,
+    ),
 }
 
 /// Turn a plugin configuration into a [`Config`] object
@@ -124,25 +163,57 @@ macro_rules! impl_config_kind {
     };
 }
 
-impl_config_kind!(ConfigKind::Integer; "Integer"; "A signed integer with 64 bits" => u64, i64);
+impl_config_kind!(ConfigKind::Integer; "Integer"; "A signed integer with 64 bits" => i64);
+impl_config_kind!(ConfigKind::Integer; "Integer"; "An unsigned integer with 64 bits" => u64);
+
+impl_config_kind!(ConfigKind::Integer; "Integer"; "A signed integer with 32 bits" => i32);
+impl_config_kind!(ConfigKind::Integer; "Integer"; "An unsigned integer with 32 bits" => u32);
+
+impl_config_kind!(ConfigKind::Integer; "Integer"; "A signed integer with 16 bits" => i16);
+impl_config_kind!(ConfigKind::Integer; "Integer"; "An unsigned integer with 16 bits" => u16);
+
+impl_config_kind!(ConfigKind::Integer; "Integer"; "A signed integer with 8 bits" => i8);
+impl_config_kind!(ConfigKind::Integer; "Integer"; "An unsigned integer with 8 bits" => u8);
+
 impl_config_kind!(ConfigKind::Float; "Float"; "A floating point value with 64 bits" => f64);
-impl_config_kind!(ConfigKind::Bool; "Boolean"; "A boolean representing either true or false" => bool);
-impl_config_kind!(ConfigKind::String; "String"; "An UTF-8 encoded string of characters" => String);
+impl_config_kind!(ConfigKind::Float; "Float"; "A floating point value with 32 bits" => f32);
+
+impl_config_kind!(ConfigKind::Bool; "Boolean"; "A boolean" => bool);
+impl_config_kind!(ConfigKind::String; "String"; "An UTF-8 string" => String);
 
 /******Pretty Printing of Configs******/
 
 impl ConfigDescription {
     /// Get a [`RcDoc`](pretty::RcDoc) which can be used to write the documentation of this
     pub fn as_terminal_doc<'a>(&'a self, arena: &'a Arena<'a>) -> RefDoc<'a> {
-        let mut doc = arena
-            .nil()
-            .append(Color::LightBlue.bold().paint(self.name()).to_string())
-            .append(arena.hardline());
+        let mut doc = arena.nil();
 
-        if let Some(conf_doc) = self.doc() {
-            let skin = MadSkin::default_dark();
-            let rendered = skin.text(&conf_doc, None).to_string();
-            doc = doc.append(arena.intersperse(
+        if !matches!(self.kind(), ConfigKind::Wrapped(_)) && self.doc().is_none() {
+            doc = doc
+                .append(Color::LightBlue.bold().paint(self.name()).to_string())
+                .append(arena.space())
+                .append(match self.kind() {
+                    ConfigKind::Bool
+                    | ConfigKind::Integer
+                    | ConfigKind::Float
+                    | ConfigKind::String
+                    | ConfigKind::Wrapped(_)
+                    | ConfigKind::Array(_)
+                    | ConfigKind::HashMap(_) => arena.nil(),
+                    ConfigKind::Struct(_) => {
+                        arena.text(Color::Blue.dimmed().paint("[Table]").to_string())
+                    }
+                    ConfigKind::Enum(_, _) => {
+                        arena.text(Color::Green.dimmed().paint("[Enum]").to_string())
+                    }
+                })
+                .append(arena.hardline());
+        }
+
+        let skin = MadSkin::default_dark();
+        let render_markdown = |text: &str| {
+            let rendered = skin.text(text, None).to_string();
+            arena.intersperse(
                 rendered.split("\n").map(|t| {
                     arena.intersperse(
                         t.split(char::is_whitespace).map(|t| t.to_string()),
@@ -150,35 +221,131 @@ impl ConfigDescription {
                     )
                 }),
                 arena.hardline(),
-            ));
+            )
+        };
+
+        if let Some(conf_doc) = self.doc() {
+            doc = doc.append(render_markdown(&conf_doc));
         }
 
         match self.kind() {
-            ConfigKind::Array(conf) => {
-                doc = doc.append(Pretty::pretty(conf.as_terminal_doc(arena), arena))
-            }
+            ConfigKind::Bool | ConfigKind::Integer | ConfigKind::Float | ConfigKind::String => (),
             ConfigKind::Struct(stc) => {
                 doc = doc
                     .append(arena.hardline())
                     .append(Color::Blue.paint("[Members]").to_string())
                     .append(arena.hardline())
                     .append(arena.intersperse(
-                        stc.iter().map(|(member_name, member_conf)| {
-                            arena
-                                .text(Color::Blue.bold().paint(member_name).to_string())
-                                .append(": ")
-                                .append(
-                                    Pretty::pretty(member_conf.as_terminal_doc(arena), arena)
-                                        .nest(4),
-                                )
+                        stc.iter().map(|(member_name, member_doc, member_conf)| {
+                            let mut doc = arena.nil();
+
+                            if let Some(member_doc) = member_doc {
+                                doc = doc.append(render_markdown(&member_doc));
+                            }
+                            doc.append(
+                                arena.text(Color::Blue.bold().paint(*member_name).to_string()),
+                            )
+                            .append(": ")
+                            .append(
+                                Pretty::pretty(member_conf.as_terminal_doc(arena), arena).nest(4),
+                            )
                         }),
                         Doc::hardline(),
                     ))
             }
-            ConfigKind::HashMap(conf) => {
-                doc = doc.append(Pretty::pretty(conf.as_terminal_doc(arena), arena))
+            ConfigKind::Enum(enum_kind, variants) => {
+                doc = doc
+                    .append(arena.hardline())
+                    .append(Color::Green.paint("One of:").to_string())
+                    .append(arena.space())
+                    .append(match enum_kind {
+                        ConfigEnumKind::Tagged(tag) => arena.text(
+                            Color::White
+                                .dimmed()
+                                .paint(format!(
+                                    "[Tagged with {}]",
+                                    Color::LightGreen
+                                        .italic()
+                                        .dimmed()
+                                        .paint(format!("'{}'", tag))
+                                ))
+                                .to_string(),
+                        ),
+                        ConfigEnumKind::Untagged => {
+                            arena.text(Color::White.dimmed().paint("[Untagged]").to_string())
+                        }
+                    })
+                    .append(arena.hardline())
+                    .append(
+                        arena.intersperse(
+                            variants
+                                .iter()
+                                .map(|(member_name, member_doc, member_conf)| {
+                                    arena.text("-").append(arena.space()).append({
+                                        let mut doc = arena
+                                            .nil()
+                                            .append(match member_conf {
+                                                EnumVariantRepresentation::String(_) => arena.text(
+                                                    Color::Green
+                                                        .bold()
+                                                        .paint(&format!(
+                                                            "{:?}",
+                                                            member_name.to_lowercase()
+                                                        ))
+                                                        .to_string(),
+                                                ),
+                                                EnumVariantRepresentation::Wrapped(_) => arena
+                                                    .text(
+                                                        Color::Green
+                                                            .bold()
+                                                            .paint(*member_name)
+                                                            .to_string(),
+                                                    ),
+                                            })
+                                            .append(": ");
+
+                                        if let Some(member_doc) = member_doc {
+                                            doc = doc.append(render_markdown(&member_doc));
+                                        }
+
+                                        doc.append(
+                                            Pretty::pretty(
+                                                match member_conf {
+                                                    EnumVariantRepresentation::String(_) => {
+                                                        arena.nil().into_doc()
+                                                    }
+
+                                                    EnumVariantRepresentation::Wrapped(
+                                                        member_conf,
+                                                    ) => arena
+                                                        .text(
+                                                            Color::LightRed
+                                                                .paint("Is a: ")
+                                                                .to_string(),
+                                                        )
+                                                        .append(member_conf.as_terminal_doc(arena))
+                                                        .into_doc(),
+                                                },
+                                                arena,
+                                            )
+                                            .nest(4),
+                                        )
+                                        .nest(2)
+                                    })
+                                }),
+                            Doc::hardline(),
+                        ),
+                    );
+            }
+            ConfigKind::Array(conf) => {
+                doc = doc
+                    .append(Color::LightRed.paint("Many of:").to_string())
+                    .append(arena.space())
+                    .append(conf.as_terminal_doc(arena));
+            }
+            ConfigKind::HashMap(conf) | ConfigKind::Wrapped(conf) => {
+                doc = doc.append(conf.as_terminal_doc(arena));
             }
-            _ => (),
         };
 
         doc.into_doc()
diff --git a/crates/core/tedge_api/src/lib.rs b/crates/core/tedge_api/src/lib.rs
index 40943224..5a9f77bb 100644
--- a/crates/core/tedge_api/src/lib.rs
+++ b/crates/core/tedge_api/src/lib.rs
@@ -12,6 +12,7 @@ pub use plugin::{Message, Plugin, PluginBuilder, PluginConfiguration, PluginDire
 
 /// Generic representation of a configuration
 pub mod config;
+pub use config::{AsConfig, ConfigDescription, ConfigKind};
 
 /// Addresses allow plugins to exchange messages
 pub mod address;
@@ -29,6 +30,9 @@ pub use message::CoreMessages;
 ///
 pub use tokio_util::sync::CancellationToken;
 
+/// Derive macro for self-describing configurations
+pub use tedge_config_derive::Config;
+
 #[doc(hidden)]
 pub mod _internal {
     pub use futures::future::BoxFuture;
diff --git a/crates/core/tedge_api/tedge_config_derive/Cargo.toml b/crates/core/tedge_api/tedge_config_derive/Cargo.toml
new file mode 100644
index 00000000..975daf1b
--- /dev/null
+++ b/crates/core/tedge_api/tedge_config_derive/Cargo.toml
@@ -0,0 +1,15 @@
+[package]
+name = "tedge_config_derive"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[lib]
+proc-macro = true
+
+[dependencies]
+proc-macro2 = "1.0.38"
+quote = "1.0.18"
+syn = { version = "1.0.93", features = ["extra-traits"] }
+proc-macro-error = "1.0.4"
diff --git a/crates/core/tedge_api/tedge_config_derive/src/lib.rs b/crates/core/tedge_api/tedge_config_derive/src/lib.rs
new file mode 100644
index 00000000..5c34dbf2
--- /dev/null
+++ b/crates/core/tedge_api/tedge_config_derive/src/lib.rs
@@ -0,0 +1,382 @@
+use proc_macro::TokenStream as TS;
+use proc_macro2::TokenStream;
+use proc_macro_error::{abort, emit_error, proc_macro_error, OptionExt, ResultExt};
+use quote::{quote, ToTokens, TokenStreamExt};
+use syn::{
+    parse_macro_input, Attribute, DeriveInput, Ident, Lit, LitStr, Meta, MetaNameValue, NestedMeta,
+    Type,
+};
+
+#[derive(Debug)]
+struct ConfigField<'q> {
+    ident: &'q Ident,
+    ty: &'q Type,
+    docs: Option<Vec<LitStr>>,
+}
+
+#[derive(Debug)]
+enum ConfigVariantKind<'q> {
+    String(&'q Ident),
+    Wrapped(&'q Ident, ConfigField<'q>),
+    Struct(&'q Ident, Vec<ConfigField<'q>>),
+}
+
+#[derive(Debug)]
+struct ConfigVariant<'q> {
+    kind: ConfigVariantKind<'q>,
+    docs: Option<Vec<LitStr>>,
+}
+
+#[derive(Debug)]
+enum ConfigEnumKind {
+    Tagged(LitStr),
+    Untagged,
+}