feat: add simple health check

Signed-off-by: kjuulh <contact@kjuulh.io>

crates/churn-agent/Cargo.toml

@@ -0,0 +1,15 @@
+[package]
+name = "churn-agent"
+version = "0.1.0"
+edition = "2021"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+anyhow.workspace = true
+tokio.workspace = true
+tracing.workspace = true
+tracing-subscriber.workspace = true
+clap.workspace = true
+dotenv.workspace = true
+axum.workspace = true

crates/churn-agent/src/main.rs

@@ -0,0 +1,58 @@
+use std::net::SocketAddr;
+
+use clap::{Parser, Subcommand};
+
+#[derive(Parser)]
+#[command(author, version, about, long_about = None, subcommand_required = true)]
+struct Command {
+    #[command(subcommand)]
+    command: Option<Commands>,
+}
+
+#[derive(Subcommand)]
+enum Commands {
+    Daemon {
+        #[arg(env = "CHURN_ADDR", long)]
+        host: SocketAddr,
+    },
+
+    Connect {
+        /// agent name is the hostname which other agents or servers can resolve and connect via. It should be unique
+        #[arg(env = "CHURN_AGENT_NAME", long)]
+        agent_name: String,
+
+        #[arg(env = "CHURN_ADDR", long)]
+        host: SocketAddr,
+
+        #[arg(env = "CHURN_TOKEN", long)]
+        token: String,
+    },
+}
+
+#[tokio::main]
+async fn main() -> anyhow::Result<()> {
+    dotenv::dotenv().ok();
+    tracing_subscriber::fmt::init();
+
+    let cli = Command::parse();
+
+    handle_command(cli).await?;
+
+    Ok(())
+}
+
+async fn handle_command(cmd: Command) -> anyhow::Result<()> {
+    match cmd.command {
+        Some(Commands::Daemon { host }) => {
+            tracing::info!("starting agent server on {}", host);
+            tokio::time::sleep(std::time::Duration::from_secs(60)).await;
+            Ok(())
+        }
+        Some(Commands::Connect {
+            host,
+            token,
+            agent_name,
+        }) => todo!(),
+        None => todo!(),
+    }
+}