feat(homelab)!: parse from env or config.toml to allow containerization

nix/homelab/src/commands/generate_routes.rs

@@ -2,7 +2,7 @@ use std::collections::BTreeSet;
 
 use serde::{Deserialize, Serialize};
 
-use crate::{Config, HelperError};
+use crate::{HelperError, config::Config};
 
 #[derive(Serialize, Deserialize, Default, Debug, Clone)]
 pub struct Route {
@@ -30,8 +30,8 @@ enum RouteKind {
     TCP,
 }
 
-pub fn generate_routes(config: &Config) -> Result<(), HelperError> {
-    let routes = config.routes.iter().enumerate().try_fold(
+pub fn generate_routes(routes: &Vec<Route>) -> Result<(), HelperError> {
+    let routes_content = routes.iter().enumerate().try_fold(
         String::new(),
         |mut acc, (i, r)| -> Result<_, HelperError> {
             if i > 0 {
@@ -41,10 +41,10 @@ pub fn generate_routes(config: &Config) -> Result<(), HelperError> {
             Ok(acc)
         },
     )?;
-    let chains = generate_chains(&config.routes);
-    std::fs::write("kustomize/routes.yaml", &routes)?;
+    let chains = generate_chains(&routes);
+    std::fs::write("kustomize/routes.yaml", &routes_content)?;
     std::fs::write("kustomize/traefik/chains.yaml", &chains)?;
-    println!("Wrote: {}", routes);
+    println!("Wrote: {}", routes_content);
 
     Ok(())
 }

nix/homelab/src/config.rs

@@ -0,0 +1,87 @@
+#[cfg(not(feature = "file-config"))]
+use std::{collections::HashSet, env};
+
+use serde::{Deserialize, Serialize};
+
+use crate::{PiHoleConfig, RouterConfig, commands::generate_routes::Route, error::Result};
+
+#[derive(Serialize, Deserialize)]
+pub struct Config {
+    pub routes: Option<Vec<Route>>,
+    pub pihole: Option<PiHoleConfig>,
+    pub router: Option<RouterConfig>,
+}
+
+#[cfg(not(feature = "file-config"))]
+struct EnvCollector {
+    missing: Vec<&'static str>,
+}
+
+#[cfg(not(feature = "file-config"))]
+impl EnvCollector {
+    fn new() -> Self {
+        Self {
+            missing: Vec::new(),
+        }
+    }
+
+    fn get(&mut self, key: &'static str) -> Option<String> {
+        match env::var(key) {
+            Ok(val) => Some(val),
+            Err(_) => {
+                self.missing.push(key);
+                None
+            }
+        }
+    }
+
+    fn finish(self) -> Result<()> {
+        if self.missing.is_empty() {
+            Ok(())
+        } else {
+            Err(crate::error::Error::MissingEnvVars(self.missing.join(", ")))
+        }
+    }
+}
+
+#[cfg(not(feature = "file-config"))]
+pub fn parse_config() -> Result<Config> {
+    let mut env = EnvCollector::new();
+
+    let pihole_url = env.get("PIHOLE_URL");
+    let pihole_password = env.get("PIHOLE_PASSWORD_FILE");
+    let pihole_hosts = env.get("PIHOLE_EXTRA_HOSTS");
+    let router_host = env.get("ROUTER_HOST");
+    let router_user = env.get("ROUTER_USER");
+    let router_key = env.get("ROUTER_KEY_PATH");
+    let router_lease = env.get("ROUTER_LEASE_FILE");
+
+    env.finish()?;
+
+    Ok(Config {
+        routes: None,
+        pihole: Some(PiHoleConfig {
+            url: pihole_url.unwrap(),
+            password_file: pihole_password.unwrap(),
+            extra_hosts: Some(
+                pihole_hosts
+                    .unwrap()
+                    .split('\n')
+                    .map(String::from)
+                    .collect::<HashSet<String>>(),
+            ),
+        }),
+        router: Some(RouterConfig {
+            host: router_host.unwrap(),
+            user: router_user.unwrap(),
+            key_path: router_key.unwrap().into(),
+            lease_file: router_lease.unwrap(),
+        }),
+    })
+}
+
+#[cfg(feature = "file-config")]
+pub fn parse_config() -> Result<Config> {
+    let bytes = std::fs::read("./config.toml")?;
+    Ok(toml::from_slice::<Config>(&bytes)?)
+}

nix/homelab/src/error.rs

@@ -14,6 +14,12 @@ pub enum Error {
     Http(#[from] reqwest::Error),
     #[error("Pi-hole API error: {0}")]
     PiHole(String),
+    #[cfg(not(feature = "file-config"))]
+    #[error("missing environment variables: {0}")]
+    MissingEnvVars(String),
+    #[cfg(feature = "file-config")]
+    #[error("error parsing toml: {0}")]
+    TomlParse(#[from] toml::de::Error),
 }
 
 pub type Result<T> = std::result::Result<T, Error>;

nix/homelab/src/main.rs

@@ -1,4 +1,5 @@
 mod commands;
+mod config;
 mod dns;
 mod error;
 mod lease_parser;
@@ -13,6 +14,7 @@ use clap::{CommandFactory, Parser};
 use serde::{Deserialize, Serialize};
 use thiserror::Error;
 
+use crate::config::parse_config;
 use crate::{
     commands::{
         Commands,
@@ -35,19 +37,10 @@ struct Cli {
 pub enum HelperError {
     #[error("error reading file")]
     ReadFile(#[from] std::io::Error),
-    #[error("error parsing config toml")]
-    TomlError(#[from] toml::de::Error),
     #[error("entrypoint required for tcproute: {0:?}")]
     TCPEntryPoint(String),
 }
 
-#[derive(Serialize, Deserialize)]
-pub struct Config {
-    routes: Vec<Route>,
-    pihole: Option<PiHoleConfig>,
-    router: Option<RouterConfig>,
-}
-
 #[derive(Serialize, Deserialize)]
 pub struct PiHoleConfig {
     url: String,
@@ -63,30 +56,20 @@ pub struct RouterConfig {
     lease_file: String,
 }
 
-pub fn parse_config<T: AsRef<Path>>(path: T) -> anyhow::Result<Config> {
-    let bytes = std::fs::read(&path).context(format!(
-        "failed to read config file: {}",
-        path.as_ref().display()
-    ))?;
-    Ok(toml::from_slice::<Config>(&bytes)?)
-}
-
-fn env_or<S: Into<String>>(key: &str, fallback: S) -> String {
-    env::var(key).unwrap_or_else(|_| fallback.into())
-}
-
 #[tokio::main(flavor = "current_thread")]
 async fn main() -> anyhow::Result<()> {
     let cli = Cli::parse();
 
     match &cli.command {
         Some(Commands::GenerateRoutes {}) => {
-            let config = parse_config("./config.toml")?;
-            generate_routes(&config)?;
+            let config = parse_config()?;
+            let routes = config
+                .routes
+                .context("routes in config are required for generating route manifests")?;
+            generate_routes(&routes)?;
         }
         Some(Commands::SyncDNS {}) => {
-            let config_path = env_or("CONFIG_PATH", "./config.toml");
-            let config = parse_config(config_path)?;
+            let config = parse_config()?;
             let pihole_config = config
                 .pihole
                 .context("pihole configuration is necessary for syncing dns")?;