feat: supports reading config values from CLI

crates/notary/server/Cargo.toml

@@ -15,6 +15,7 @@ axum-core = { version = "0.4" }
 axum-macros = { version = "0.4" }
 base64 = { version = "0.21" }
 chrono = { version = "0.4" }
+config = { version = "0.14", features = ["yaml"] }
 csv = { version = "1.3" }
 eyre = { version = "0.6" }
 futures = { workspace = true }

crates/notary/server/config/config.yaml

@@ -29,4 +29,4 @@ logging:
 
 authorization:
   enabled: false
-  whitelist-csv-path: "./fixture/auth/whitelist.csv"
+  whitelist-csv-path: "./fixture/auth/whitelist.csv"

crates/notary/server/src/config.rs

@@ -51,9 +51,7 @@ pub struct ServerProperties {
 #[derive(Clone, Debug, Deserialize, Default)]
 #[serde(rename_all = "kebab-case")]
 pub struct TLSProperties {
-    /// Flag to turn on/off TLS between prover and notary (should always be
-    /// turned on unless TLS is handled by external setup e.g. reverse proxy,
-    /// cloud)
+    /// Flag to turn on/off TLS between prover and notary (should always be turned on unless TLS is handled by external setup e.g. reverse proxy, cloud)
     pub enabled: bool,
     pub private_key_pem_path: String,
     pub certificate_pem_path: String,

crates/notary/server/src/domain/cli.rs

@@ -7,4 +7,13 @@ pub struct CliFields {
     /// Configuration file location
     #[structopt(long, default_value = "./config/config.yaml")]
     pub config_file: String,
+
+    #[structopt(long)]
+    pub port: Option<u16>,
+
+    #[structopt(long)]
+    pub tls_enabled: Option<bool>,
+
+    #[structopt(long)]
+    pub log_level: Option<String>,
 }

crates/notary/server/src/lib.rs

@@ -5,6 +5,7 @@ mod middleware;
 mod server;
 mod server_tracing;
 mod service;
+mod settings;
 mod signing;
 mod util;
 
@@ -19,4 +20,5 @@ pub use domain::{
 pub use error::NotaryServerError;
 pub use server::{read_pem_file, run_server};
 pub use server_tracing::init_tracing;
+pub use settings::Settings;
 pub use util::parse_config_file;

crates/notary/server/src/main.rs

@@ -1,25 +1,27 @@
 use eyre::{eyre, Result};
 use structopt::StructOpt;
 use tracing::debug;
-
 use notary_server::{
-    init_tracing, parse_config_file, run_server, CliFields, NotaryServerError,
-    NotaryServerProperties,
+    init_tracing, run_server, CliFields, NotaryServerError,
+    Settings
 };
 
 #[tokio::main]
 async fn main() -> Result<(), NotaryServerError> {
-    // Load command line arguments which contains the config file location
+    // Load command line arguments
     let cli_fields: CliFields = CliFields::from_args();
-    let config: NotaryServerProperties = parse_config_file(&cli_fields.config_file)?;
+
+    let settings = Settings::new(&cli_fields)
+        .map_err(|err| eyre!("Failed to load settings: {}", err))?;
 
     // Set up tracing for logging
-    init_tracing(&config).map_err(|err| eyre!("Failed to set up tracing: {err}"))?;
+    init_tracing(&settings.config)
+        .map_err(|err| eyre!("Failed to set up tracing: {err}"))?;
 
-    debug!(?config, "Server config loaded");
+    debug!(?settings.config, "Server config loaded");
 
     // Run the server
-    run_server(&config).await?;
+    run_server(&settings.config).await?;
 
     Ok(())
-}
+}

crates/notary/server/src/settings.rs

@@ -0,0 +1,39 @@
+use config::{Config, ConfigError, Environment, File};
+use std::path::Path;
+use crate::{ CliFields, NotaryServerProperties };
+use serde::Deserialize;
+
+#[derive(Debug, Deserialize)]
+pub struct Settings {
+    #[serde(flatten)]
+    pub config: NotaryServerProperties,
+}
+
+impl Settings {
+    pub fn new(cli_fields: &CliFields) -> Result<Self, ConfigError> {
+        let config_path = Path::new(&cli_fields.config_file);
+
+        let mut builder = Config::builder()
+            // Load base configuration
+            .add_source(File::from(config_path))
+            // Add in settings from environment variables (with a prefix of NOTARY_SERVER and '__' as separator)
+            .add_source(Environment::with_prefix("NOTARY_SERVER").try_parsing(true).prefix_separator("__").separator("_"));
+
+        // Apply CLI argument overrides
+        if let Some(port) = cli_fields.port {
+            builder = builder.set_override("server.port", port)?;
+        }
+        if let Some(tls_enabled) = cli_fields.tls_enabled {
+            builder = builder.set_override("tls.enabled", tls_enabled)?;
+        }
+        if let Some(log_level) = &cli_fields.log_level {
+            builder = builder.set_override("logging.level", log_level.clone())?;
+        }
+
+        let config = builder.build()?;
+
+        let settings: Settings = config.try_deserialize()?;
+
+        Ok(settings)
+    }
+}