Merge pull request 'Environment parsing done with Serde Envy' (#5) from adrien/diplonat:feature/config-handling into main

Reviewed-on: https://git.deuxfleurs.fr/Deuxfleurs/diplonat/pulls/5

4 files changed, 328 insertions, 0 deletions

diff --git a/src/config/mod.rs b/src/config/mod.rs
new file mode 100644
index 0000000..14926bd
--- /dev/null
+++ b/src/config/mod.rs
@@ -0,0 +1,11 @@
+mod options;
+#[cfg(test)]
+mod options_test;
+mod runtime;
+
+pub use options::{ConfigOpts, ConfigOptsAcme, ConfigOptsBase, ConfigOptsConsul};
+pub use runtime::{RuntimeConfig, RuntimeConfigAcme, RuntimeConfigConsul, RuntimeConfigFirewall, RuntimeConfigIgd};
+
+pub const EXPIRATION_TIME: u16 = 300;
+pub const REFRESH_TIME: u16 = 60;
+pub const CONSUL_URL: &str = "http://127.0.0.1:8500";
\ No newline at end of file
diff --git a/src/config/options.rs b/src/config/options.rs
new file mode 100644
index 0000000..36da475
--- /dev/null
+++ b/src/config/options.rs
@@ -0,0 +1,76 @@
+use anyhow::Result;
+use serde::Deserialize;
+
+use crate::config::RuntimeConfig;
+
+// This code is inspired by the Trunk crate (https://github.com/thedodd/trunk)
+
+// This file parses the options that can be declared in the environment.
+// runtime.rs applies business logic and builds RuntimeConfig structs.
+
+/// Base configuration options
+#[derive(Clone, Default, Deserialize)]
+pub struct ConfigOptsBase {
+	/// This node's private IP address [default: None]
+	pub private_ip: Option<String>,
+	/// Expiration time for IGD rules [default: 60]
+	pub expiration_time: Option<u16>,
+	/// Refresh time for IGD and Firewall rules [default: 300]
+	pub refresh_time: Option<u16>,
+}
+
+/// ACME configuration options
+#[derive(Clone, Default, Deserialize)]
+pub struct ConfigOptsAcme {
+	/// Whether ACME is enabled [default: false]
+	#[serde(default)]
+	pub enable: bool,
+
+	/// The default domain holder's e-mail [default: None]
+	pub email: Option<String>,
+}
+
+/// Consul configuration options
+#[derive(Clone, Default, Deserialize)]
+pub struct ConfigOptsConsul {
+	/// Consul's node name [default: None]
+	pub node_name: Option<String>,
+	/// Consul's REST URL [default: "http://127.0.0.1:8500"]
+	pub url: Option<String>,
+}
+
+/// Model of all potential configuration options
+pub struct ConfigOpts {
+	pub base: ConfigOptsBase,
+	pub acme: ConfigOptsAcme,
+	pub consul: ConfigOptsConsul,
+}
+
+impl ConfigOpts {
+	pub fn from_env() -> Result<RuntimeConfig> {
+		let base: ConfigOptsBase = envy::prefixed("DIPLONAT_").from_env()?;
+		let consul: ConfigOptsConsul = envy::prefixed("DIPLONAT_CONSUL_").from_env()?;
+		let acme: ConfigOptsAcme = envy::prefixed("DIPLONAT_ACME_").from_env()?;
+
+		RuntimeConfig::new(Self {
+			base: base,
+			consul: consul,
+			acme: acme,
+		})
+	}
+
+	// Currently only used in tests
+	#[allow(dead_code)]
+	pub fn from_iter<Iter: Clone>(iter: Iter) -> Result<RuntimeConfig>
+	where Iter: IntoIterator<Item = (String, String)> {
+		let base: ConfigOptsBase = envy::prefixed("DIPLONAT_").from_iter(iter.clone())?;
+		let consul: ConfigOptsConsul = envy::prefixed("DIPLONAT_CONSUL_").from_iter(iter.clone())?;
+		let acme: ConfigOptsAcme = envy::prefixed("DIPLONAT_ACME_").from_iter(iter.clone())?;
+
+		RuntimeConfig::new(Self {
+			base: base,
+			consul: consul,
+			acme: acme,
+		})
+	}
+}
\ No newline at end of file
diff --git a/src/config/options_test.rs b/src/config/options_test.rs
new file mode 100644
index 0000000..a6063fd
--- /dev/null
+++ b/src/config/options_test.rs
@@ -0,0 +1,120 @@
+use std::collections::HashMap;
+use std::time::Duration;
+
+use crate::config::*;
+
+// Environment variables are set for the entire process and
+// tests are run whithin the same process.
+// => We cannot test ConfigOpts::from_env(), 
+// because tests modify each other's environment.
+// This is why we only test ConfigOpts::from_iter(iter).
+
+fn minimal_valid_options() -> HashMap<String, String> {
+	let mut opts = HashMap::new();
+	opts.insert("DIPLONAT_PRIVATE_IP".to_string(), "172.123.43.555".to_string());
+    opts.insert("DIPLONAT_CONSUL_NODE_NAME".to_string(), "consul_node".to_string());
+    opts
+}
+
+fn all_valid_options() -> HashMap<String, String> {
+	let mut opts = minimal_valid_options();
+	opts.insert("DIPLONAT_EXPIRATION_TIME".to_string(), "30".to_string());
+	opts.insert("DIPLONAT_REFRESH_TIME".to_string(), "10".to_string());
+    opts.insert("DIPLONAT_CONSUL_URL".to_string(), "http://127.0.0.1:9999".to_string());
+	opts.insert("DIPLONAT_ACME_ENABLE".to_string(), "true".to_string());
+	opts.insert("DIPLONAT_ACME_EMAIL".to_string(), "bozo@bozo.net".to_string());
+    opts
+}
+
+#[test]
+#[should_panic]
+fn err_empty_env() {
+	std::env::remove_var("DIPLONAT_PRIVATE_IP");
+	std::env::remove_var("DIPLONAT_CONSUL_NODE_NAME");
+	ConfigOpts::from_env().unwrap();
+}
+
+#[test]
+fn ok_from_iter_minimal_valid_options() {
+	let opts = minimal_valid_options();
+	let rt_config = ConfigOpts::from_iter(opts.clone()).unwrap();
+
+	assert!(rt_config.acme.is_none());
+	assert_eq!(
+		&rt_config.consul.node_name, 
+		opts.get(&"DIPLONAT_CONSUL_NODE_NAME".to_string()).unwrap()
+	);
+	assert_eq!(
+		rt_config.consul.url, 
+		CONSUL_URL.to_string()
+	);
+	assert_eq!(
+		rt_config.firewall.refresh_time,
+		Duration::from_secs(REFRESH_TIME.into())
+	);
+	assert_eq!(
+		&rt_config.igd.private_ip,
+		opts.get(&"DIPLONAT_PRIVATE_IP".to_string()).unwrap()
+	);
+	assert_eq!(
+		rt_config.igd.expiration_time,
+		Duration::from_secs(EXPIRATION_TIME.into())
+	);
+	assert_eq!(
+		rt_config.igd.refresh_time,
+		Duration::from_secs(REFRESH_TIME.into())
+	);
+}
+
+#[test]
+#[should_panic]
+fn err_from_iter_invalid_refresh_time() {
+	let mut opts = minimal_valid_options();
+	opts.insert("DIPLONAT_EXPIRATION_TIME".to_string(), "60".to_string());
+	opts.insert("DIPLONAT_REFRESH_TIME".to_string(), "60".to_string());
+	ConfigOpts::from_iter(opts).unwrap();
+}
+
+#[test]
+fn ok_from_iter_all_valid_options() {
+	let opts = all_valid_options();
+	let rt_config = ConfigOpts::from_iter(opts.clone()).unwrap();
+
+	let expiration_time = Duration::from_secs(
+		opts.get(&"DIPLONAT_EXPIRATION_TIME".to_string()).unwrap()
+			.parse::<u64>().unwrap()
+			.into());
+	let refresh_time = Duration::from_secs(
+		opts.get(&"DIPLONAT_REFRESH_TIME".to_string()).unwrap()
+			.parse::<u64>().unwrap()
+			.into());
+
+	assert!(rt_config.acme.is_some());
+	assert_eq!(
+		&rt_config.acme.unwrap().email,
+		opts.get(&"DIPLONAT_ACME_EMAIL".to_string()).unwrap());
+	assert_eq!(
+		&rt_config.consul.node_name, 
+		opts.get(&"DIPLONAT_CONSUL_NODE_NAME".to_string()).unwrap()
+	);
+	assert_eq!(
+		&rt_config.consul.url, 
+		opts.get(&"DIPLONAT_CONSUL_URL".to_string()).unwrap()
+	);
+	assert_eq!(
+		rt_config.firewall.refresh_time,
+		refresh_time
+	);
+	assert_eq!(
+		&rt_config.igd.private_ip,
+		opts.get(&"DIPLONAT_PRIVATE_IP".to_string()).unwrap()
+	);
+	assert_eq!(
+		rt_config.igd.expiration_time,
+		expiration_time
+	);
+	assert_eq!(
+		rt_config.igd.refresh_time,
+		refresh_time
+	);
+}
\ No newline at end of file
diff --git a/src/config/runtime.rs b/src/config/runtime.rs
new file mode 100644
index 0000000..58c86b9
--- /dev/null
+++ b/src/config/runtime.rs
@@ -0,0 +1,121 @@
+use std::time::Duration;
+
+use anyhow::{Result, anyhow};
+
+use crate::config::{ConfigOpts, ConfigOptsAcme, ConfigOptsBase, ConfigOptsConsul};
+
+// This code is inspired by the Trunk crate (https://github.com/thedodd/trunk)
+
+// In this file, we take ConfigOpts and transform them into ready-to-use RuntimeConfig.
+// We apply default values and business logic.
+
+#[derive(Debug)]
+pub struct RuntimeConfigAcme {
+	pub email: String,
+}
+
+#[derive(Debug)]
+pub struct RuntimeConfigConsul {
+	pub node_name: String,
+	pub url: String,
+}
+
+#[derive(Debug)]
+pub struct RuntimeConfigFirewall {
+	pub refresh_time: Duration,
+}
+
+#[derive(Debug)]
+pub struct RuntimeConfigIgd {
+	pub private_ip: String,
+	pub expiration_time: Duration,
+	pub refresh_time: Duration,
+}
+
+#[derive(Debug)]
+pub struct RuntimeConfig {
+	pub acme: Option<RuntimeConfigAcme>,
+	pub consul: RuntimeConfigConsul,
+	pub firewall: RuntimeConfigFirewall,
+	pub igd: RuntimeConfigIgd,
+}
+
+impl RuntimeConfig {
+	pub fn new(opts: ConfigOpts) -> Result<Self> {
+		let acme = RuntimeConfigAcme::new(opts.acme.clone())?;
+		let consul = RuntimeConfigConsul::new(opts.consul.clone())?;
+		let firewall = RuntimeConfigFirewall::new(opts.base.clone())?;
+		let igd = RuntimeConfigIgd::new(opts.base.clone())?;
+
+		Ok(Self {
+			acme,
+			consul,
+			firewall,
+			igd,
+		})
+	}
+}
+
+impl RuntimeConfigAcme {
+	pub fn new(opts: ConfigOptsAcme) -> Result<Option<Self>> {
+		if !opts.enable {
+			return Ok(None);
+		}
+
+		let email = opts.email.expect(
+			"'DIPLONAT_ACME_EMAIL' environment variable is required \
+			if 'DIPLONAT_ACME_ENABLE' == 'true'");
+
+		Ok(Some(Self {
+			email,
+		}))
+	}
+}
+
+impl RuntimeConfigConsul {
+	pub(super) fn new(opts: ConfigOptsConsul) -> Result<Self> {
+		let node_name = opts.node_name.expect(
+			"'DIPLONAT_CONSUL_NODE_NAME' environment variable is required");
+		let url = opts.url.unwrap_or(super::CONSUL_URL.to_string());
+
+		Ok(Self {
+			node_name,
+			url,
+		})
+	}
+}
+
+impl RuntimeConfigFirewall {
+	pub(super) fn new(opts: ConfigOptsBase) -> Result<Self> {
+		let refresh_time = Duration::from_secs(
+				opts.refresh_time.unwrap_or(super::REFRESH_TIME).into());
+
+		Ok(Self {
+			refresh_time,
+		})
+	}
+}
+
+impl RuntimeConfigIgd {
+	pub(super) fn new(opts: ConfigOptsBase) -> Result<Self> {
+		let private_ip = opts.private_ip.expect(
+			"'DIPLONAT_PRIVATE_IP' environment variable is required");
+		let expiration_time = Duration::from_secs(
+				opts.expiration_time.unwrap_or(super::EXPIRATION_TIME).into());
+		let refresh_time = Duration::from_secs(
+				opts.refresh_time.unwrap_or(super::REFRESH_TIME).into());
+
+		if refresh_time.as_secs() * 2 > expiration_time.as_secs() {
+	      return Err(anyhow!(
+	        "IGD expiration time (currently: {}s) must be at least twice bigger than refresh time (currently: {}s)", 
+	        expiration_time.as_secs(),
+	        refresh_time.as_secs()));
+	    }
+
+		Ok(Self {
+			private_ip,
+			expiration_time,
+			refresh_time,
+		})
+	}
+}
\ No newline at end of file