feat(runtime): Remove dependency on clap (#822)

runtime/Cargo.toml

@@ -16,7 +16,6 @@ doctest = false
 anyhow = { workspace = true }
 async-trait = { workspace = true }
 chrono = { workspace = true }
-clap = { workspace = true }
 prost-types = { workspace = true }
 serde = { workspace = true }
 serde_json = { workspace = true }

runtime/src/alpha/args.rs

@@ -1,37 +1,33 @@
-use std::path::PathBuf;
+use std::{fmt::Debug, path::PathBuf, str::FromStr};
 
-use clap::{Parser, ValueEnum};
 use tonic::transport::{Endpoint, Uri};
 
-#[derive(Parser, Debug)]
-#[command(version)]
-pub struct Args {
-    /// Port to start runtime on
-    #[arg(long)]
-    pub port: u16,
+use crate::args::args;
 
-    /// Address to reach provisioner at
-    #[arg(long, default_value = "http://localhost:3000")]
-    pub provisioner_address: Endpoint,
-
-    /// Type of storage manager to start
-    #[arg(long, value_enum)]
-    pub storage_manager_type: StorageManagerType,
-
-    /// Path to use for storage manager
-    #[arg(long)]
-    pub storage_manager_path: PathBuf,
-
-    /// Address to reach the authentication service at
-    #[arg(long, default_value = "http://127.0.0.1:8008")]
-    pub auth_uri: Uri,
+args! {
+    pub struct Args {
+        "--port" => pub port: u16,
+        "--provisioner-address" => #[arg(default_value = "http://localhost:3000")] pub provisioner_address: Endpoint,
+        "--storage-manager-type" => pub storage_manager_type: StorageManagerType,
+        "--storage-manager-path" => pub storage_manager_path: PathBuf,
+        "--auth-uri" => #[arg(default_value = "http://127.0.0.1:8008")] pub auth_uri: Uri,
+    }
 }
 
-#[derive(Clone, Debug, ValueEnum)]
+#[derive(Clone, Debug)]
 pub enum StorageManagerType {
-    /// Use a deloyer artifacts directory
     Artifacts,
-
-    /// Use a local working directory
     WorkingDir,
 }
+
+impl FromStr for StorageManagerType {
+    type Err = ();
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        match s {
+            "artifacts" => Ok(StorageManagerType::Artifacts),
+            "working-dir" => Ok(StorageManagerType::WorkingDir),
+            _ => Err(()),
+        }
+    }
+}

runtime/src/alpha/mod.rs

@@ -10,7 +10,6 @@ use std::{
 
 use anyhow::Context;
 use async_trait::async_trait;
-use clap::Parser;
 use core::future::Future;
 use shuttle_common::{
     backends::{
@@ -51,7 +50,7 @@ use self::args::Args;
 mod args;
 
 pub async fn start(loader: impl Loader<ProvisionerFactory> + Send + 'static) {
-    let args = Args::parse();
+    let args = Args::parse().expect("could not parse arguments");
     let addr = SocketAddr::new(Ipv4Addr::LOCALHOST.into(), args.port);
 
     let provisioner_address = args.provisioner_address;

runtime/src/args.rs

@@ -0,0 +1,80 @@
+#[derive(Debug)]
+pub enum Error {
+    DuplicatedArgument { arg: &'static str },
+    MissingRequiredArgument { arg: &'static str },
+    UnexpectedArgument { arg: String },
+
+    InvalidValue { arg: &'static str, value: String },
+    MissingValue { arg: &'static str },
+}
+
+impl std::fmt::Display for Error {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            Self::DuplicatedArgument { arg } => write!(f, "duplicated argument {arg}"),
+            Self::MissingRequiredArgument { arg } => write!(f, "missing required argument {arg}"),
+            Self::UnexpectedArgument { arg } => write!(f, "unexpected argument: {arg}"),
+
+            Self::InvalidValue { arg, value } => {
+                write!(f, "invalid value for argument {arg}: {value}")
+            }
+            Self::MissingValue { arg } => write!(f, "missing value for argument {arg}"),
+        }
+    }
+}
+
+impl std::error::Error for Error {}
+
+macro_rules! args {
+    // Internal rules used to handle optional default values
+    (@unwrap $arg:literal, $field:ident $(,)?) => {
+        $field.ok_or_else(|| $crate::args::Error::MissingRequiredArgument { arg: $arg })?
+    };
+    (@unwrap $arg:literal, $field:ident, $default:literal) => {
+        $field.unwrap_or_else(|| $default.parse().unwrap())
+    };
+
+    (
+        pub struct $struct:ident {
+            $($arg:literal => $(#[arg(default_value = $default:literal)])? pub $field:ident: $ty:ty),+ $(,)?
+        }
+    ) => {
+        #[derive(::std::fmt::Debug)]
+        pub struct $struct {
+            $(pub $field: $ty,)+
+        }
+
+        impl $struct {
+            pub fn parse() -> ::std::result::Result<Self, $crate::args::Error> {
+                $(let mut $field: ::std::option::Option<$ty> = None;)+
+
+                // The first argument is the path of the executable.
+                let mut args_iter = ::std::env::args().skip(1);
+                while let ::std::option::Option::Some(arg) = args_iter.next() {
+                    match arg.as_str() {
+                        $($arg => {
+                            if $field.is_some() {
+                                return ::std::result::Result::Err($crate::args::Error::DuplicatedArgument { arg: $arg });
+                            }
+                            let raw_value = args_iter
+                                .next()
+                                .ok_or_else(|| $crate::args::Error::MissingValue { arg: $arg })?;
+                            let value = raw_value.parse().map_err(|_| $crate::args::Error::InvalidValue {
+                                arg: $arg,
+                                value: raw_value,
+                            })?;
+                            $field = ::std::option::Option::Some(value);
+                        })+
+                        _ => return ::std::result::Result::Err($crate::args::Error::UnexpectedArgument { arg }),
+                    }
+                }
+
+                ::std::result::Result::Ok($struct {
+                    $($field: $crate::args::args!(@unwrap $arg, $field, $($default)?),)+
+                })
+            }
+        }
+    }
+}
+
+pub(crate) use args;

runtime/src/bin/shuttle-next.rs

@@ -3,7 +3,6 @@ use std::{
     time::Duration,
 };
 
-use clap::Parser;
 use shuttle_common::backends::tracing::{setup_tracing, ExtractPropagationLayer};
 use shuttle_proto::runtime::runtime_server::RuntimeServer;
 use shuttle_runtime::{AxumWasm, NextArgs};
@@ -12,7 +11,7 @@ use tracing::trace;
 
 #[tokio::main(flavor = "multi_thread")]
 async fn main() {
-    let args = NextArgs::parse();
+    let args = NextArgs::parse().unwrap();
 
     setup_tracing(tracing_subscriber::registry(), "shuttle-next");
 

runtime/src/lib.rs

@@ -215,6 +215,7 @@
 //! You can also [open an issue or a discussion on GitHub](https://github.com/shuttle-hq/shuttle).
 //!
 mod alpha;
+mod args;
 mod logger;
 #[cfg(feature = "next")]
 mod next;

runtime/src/next/args.rs

@@ -1,9 +1,7 @@
-use clap::Parser;
+use crate::args::args;
 
-#[derive(Parser, Debug)]
-#[command(version)]
-pub struct NextArgs {
-    /// Port to start runtime on
-    #[arg(long)]
-    pub port: u16,
+args! {
+    pub struct NextArgs {
+        "--port" => pub port: u16,
+    }
 }