[web] Add support for reading from a configuration file

web/Cargo.toml

@@ -12,6 +12,8 @@ log = "0.4"
 env_logger = "0.9"
 askama = "0.10"
 argh = "0.1.6"
+serde = "1.0"
+serde_yaml = "0.8"
 rusttype = { version = "0.9.2", optional = true }
 image = { version = "0.23.14", optional = true }
 lazy_static = { version = "1.4.0", optional = true }

web/src/configuration.rs

@@ -1,4 +1,9 @@
+use std::fs::OpenOptions;
+use std::fs::File;
+use std::io::Write;
+use pronouns_today::InstanceSettings;
 use argh::FromArgs;
+use serde::{Deserialize, Serialize};
 
 #[derive(FromArgs, PartialEq, Debug)]
 /// Everything you need to selfhost a pronouns.today server
@@ -45,12 +50,14 @@ pub struct Run {
 				   option,
 				   default = "String::from(\"/etc/pronouns_today.yml\")",
 				   short = 'c'))]
-	/// path to the config file (generated if needed)
+	/// path to the config file (generated if needed).  Defaults to
+	/// /etc/pronouns_today.yml
 	pub config: String,
 
 	#[argh(switch)]
-	/// don't generate a config file if not present
-	pub no_generate_cfg: bool,
+	/// don't attempt to read or generate a config file, just use command line args.  Missing
+	/// options will be filled in using sane defaults
+	pub no_read_cfg: bool,
 
 	#[argh(option, short = 'p')]
 	/// the port to listen on
@@ -61,3 +68,81 @@ pub struct Run {
 	/// used in the custom URLs, e.g. "acaqeawdym")
 	pub default_prefstr: Option<String>,
 }
+
+impl Run {
+	/// Read the config from the provided file, and apply overrides from args
+	///
+	/// If `--no-read-cfg` was passed, no config file is present, and there aren't
+	/// enough args to populate the configuration, returns an [`Err`] with a list of
+	/// arguments that were missing.
+	pub fn load_config(&self) -> Result<Conf, ConfigError> {
+		if !self.no_read_cfg {
+			match File::open(&self.config) {
+				Ok(raw_cfg) => {
+					serde_yaml::from_reader(raw_cfg)
+						.map_err(ConfigError::MalformedConfig)
+				}
+				Err(e) if e.kind() == std::io::ErrorKind::NotFound => {
+					OpenOptions::new()
+						.write(true)
+						.create(true)
+						.open(&self.config)
+						.and_then(|mut c|
+							c.write_all(include_bytes!("../assets/default_config.yml"))
+						)
+						.map_err(ConfigError::IoError)?;
+					Err(ConfigError::ConfigCreated(self.config.clone()))
+				}
+				Err(e) => {
+					Err(ConfigError::IoError(e))
+				}
+			}
+		} else {
+            Ok(Conf::default())
+		}.map(|config| config.update_with(&self))
+	}
+}
+
+#[derive(Clone, Serialize, Deserialize, Debug)]
+/// A parsed config file for Pronouns.Today web
+pub struct Conf {
+
+	#[serde(flatten)]
+	/// General settings for the pronouns.today library
+	pub instance_settings: InstanceSettings,
+
+	/// The port for the server to bind to.  Defaults to 1312
+	pub port: u16,
+}
+
+impl Conf {
+	fn update_with(mut self, args: &Run) -> Conf {
+		self.port = args.port.unwrap_or(self.port);
+		self
+	}
+}
+
+impl Default for Conf {
+    fn default() -> Self {
+        Conf {
+            instance_settings: InstanceSettings::default(),
+            port: 1312,
+        }
+    }
+}
+
+/// An error occured while trying to load the configuration
+pub enum ConfigError {
+
+	/// There wase a problem reading/writing the config file
+	IoError(std::io::Error),
+
+	/// There wase a problem deserializing the config file
+	MalformedConfig(serde_yaml::Error),
+
+	/// The config file was missing, but has been created
+	///
+	/// The program should now prompt the user to fill the config in, and then exit.  The
+	/// provided [`String`] contains the path to the new config file
+	ConfigCreated(String),
+}

web/src/main.rs

@@ -3,6 +3,9 @@ pub mod contrast;
 pub mod statics;
 pub mod configuration;
 
+use configuration::ConfigError;
+
+use std::process::exit;
 use std::collections::HashMap;
 use std::fmt::{self, Display};
 
@@ -142,6 +145,7 @@ async fn not_found() -> impl Responder {
 #[actix_web::main]
 async fn main() -> std::io::Result<()> {
 
+    env_logger::init();
 	let args: configuration::PronounsTodayArgs = argh::from_env();
 
 	match args.command {
@@ -149,14 +153,30 @@ async fn main() -> std::io::Result<()> {
 			println!("Support for dumping statics not yet implemented");
 			Ok(())
 		}
-		configuration::SubCommand::Run(_subargs) => {
+		configuration::SubCommand::Run(subargs) => {
+			let config = match subargs.load_config() {
+				Ok(config) => config,
+				Err(ConfigError::IoError(e)) => {
+					return Err(e);
+				}
+				Err(ConfigError::MalformedConfig(e)) => {
+					eprintln!("Error parsing config file:\n{}", e);
+					exit(1001);
+				}
+				Err(ConfigError::ConfigCreated(path)) => {
+					println!("A config file has been generated at {}!  Please check it out
+							 and modify it to your liking, and then run this command
+							 again", path);
+					exit(0);
+				}
+			};
+			log::info!("Starting with configuration {:?}", config);
 			start_server().await
 		}
 	}
 }
 
 async fn start_server() -> std::io::Result<()> {
-    env_logger::init();
 	println!("Starting pronouns-today-web on 127.0.0.1:8080");
     HttpServer::new(|| {
         let logger = Logger::default();