Set up the right dependencies and bring the bits of a lambda_runtime example in

Cargo.toml

@@ -5,3 +5,9 @@ authors = ["R. Tyler Croy <rtyler@brokenco.de>"]
 edition = "2018"
 
 [dependencies]
+deltalake = { git = "https://github.com/delta-io/delta-rs", branch = "main", features = ["s3"] }
+lambda_runtime = "0.3"
+log = "0.4"
+pretty_env_logger = "0.4"
+tokio = { version = "1.0", features = ["macros"]}
+serde = { version = "1", features = ["rc", "derive"]}

src/main.rs

@@ -1,3 +1,50 @@
-fn main() {
-    println!("Hello, world!");
+/*
+ * The bulk of the application
+ */
+
+use deltalake::*;
+use lambda_runtime::{handler_fn, Context, Error};
+use log::*;
+use serde::{Deserialize, Serialize};
+
+/// This is also a made-up example. Requests come into the runtime as unicode
+/// strings in json format, which can map to any structure that implements `serde::Deserialize`
+/// The runtime pays no attention to the contents of the request payload.
+#[derive(Deserialize)]
+struct Request {
+    command: String,
+}
+
+/// This is a made-up example of what a response structure may look like.
+/// There is no restriction on what it can be. The runtime requires responses
+/// to be serialized into json. The runtime pays no attention
+/// to the contents of the response payload.
+#[derive(Serialize)]
+struct Response {
+    req_id: String,
+    msg: String,
+}
+
+#[tokio::main]
+async fn main() -> Result<(), Error> {
+    pretty_env_logger::init();
+    info!("Initializing delta-s3-loader v{}", env!["CARGO_PKG_VERSION"]);
+
+    let func = handler_fn(my_handler);
+    lambda_runtime::run(func).await?;
+    Ok(())
+}
+
+async fn my_handler(event: Request, ctx: Context) -> Result<Response, Error> {
+    // extract some useful info from the request
+    let command = event.command;
+
+    // prepare the response
+    let resp = Response {
+        req_id: ctx.request_id,
+        msg: format!("Command {} executed.", command),
+    };
+
+    // return `Response` (it will be serialized to JSON automatically by the runtime)
+    Ok(resp)
 }