Use Environment Variables instead of CLI Arguments (#18)

Cargo.toml

@@ -31,6 +31,8 @@ sha3 = "0.10"
 regex = "1"
 rustc-hex= "2.1"
 peg = "0.8"
+dotenvy = "0.15.7"
+envy = "0.4.2"
 
 [dev-dependencies]
 jsonrpsee = { version = "0.21", features = ["macros", "server", "client"] }

example.env

@@ -0,0 +1,2 @@
+ADDRESS="127.0.0.1:9944"
+PROVIDER="http://127.0.0.1:8545"

src/lib.rs

@@ -85,9 +85,9 @@ pub mod types;
 mod util;
 
 use std::str::FromStr;
+use serde::Deserialize;
 
 use anyhow::Result;
-use argh::FromArgs;
 use ethers::types::Address;
 use jsonrpsee::server::Server;
 
@@ -97,34 +97,42 @@ pub use crate::{
     rpc::DidRegistryServer,
 };
 
+const DEFAULT_ADDRESS: &str = "127.0.0.1:9944";
+const DEFAULT_PROVIDER: &str = "http://127.0.0.1:8545";
+
 // TODO: Get registry address from environment variable, or configuration file
 // in order to support multiple chains, we may need to support multiple providers via RPC
 // so it could be worth defining a config file that maps chainId to RPC provider (like
 // did-eth-resolver)
 /// The address of the DID Registry contract on the Ethereum Sepolia Testnet
 pub const DID_ETH_REGISTRY: &str = "0xd1D374DDE031075157fDb64536eF5cC13Ae75000";
 
-#[derive(FromArgs)]
+#[derive(Deserialize)]
 /// DID Ethereum Resolver XMTP Gateway
 struct DidEthGatewayApp {
     /// the address to start the server
-    #[argh(option, short = 'a', default = "String::from(\"127.0.0.1:9944\")")]
+    #[serde(default= "default_address")]
     address: String,
 
     /// ethereum RPC Provider
-    #[argh(
-        option,
-        short = 'p',
-        default = "String::from(\"wss://eth.llamarpc.com\")"
-    )]
+    #[serde(default= "default_provider")]
     provider: String,
 }
 
+fn default_address() -> String {
+    DEFAULT_ADDRESS.to_string()
+}
+
+fn default_provider() -> String {
+    DEFAULT_PROVIDER.to_string()
+}
+
 /// Entrypoint for the did:ethr Gateway
 pub async fn run() -> Result<()> {
     crate::util::init_logging();
-    let opts: DidEthGatewayApp = argh::from_env();
-
+    dotenvy::dotenv()?;
+    let opts: DidEthGatewayApp = envy::from_env()?;
+
     let server = Server::builder().build(opts.address).await?;
     let addr = server.local_addr()?;
     let registry_address = Address::from_str(DID_ETH_REGISTRY)?;
@@ -135,3 +143,14 @@ pub async fn run() -> Result<()> {
     handle.stopped().await;
     Ok(())
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn internal() {
+        assert_eq!(DEFAULT_ADDRESS, default_address());
+        assert_eq!(DEFAULT_PROVIDER, default_provider());
+    }
+}