aws-lambda-runtime 0.3 or lambda example

main.rs

extern crate lambda;
#[macro_use]
extern crate serde;

use rusoto_dynamodb::{DynamoDbClient, DynamoDb, PutItemInput, AttributeValue};
use rusoto_core::Region;
use std::collections::HashMap;
use uuid::Uuid;
use lambda::{handler_fn, Context};

type Error = Box<dyn std::error::Error + Send + Sync + 'static>;

#[tokio::main]
async fn main() -> Result<(), Error> {
    let func = handler_fn(handler);
    lambda::run(func).await?;
    Ok(())
}

#[derive(Serialize, Deserialize)]
#[serde(rename_all = "camelCase")]
struct CustomEvent {
    param: String,
}

#[derive(Serialize, Deserialize)]
#[serde(rename_all = "camelCase")]
struct CustomResult {
    result: String,
}

async fn handler(event: CustomEvent, _context: Context) -> Result<CustomResult, Error> {
    let client = DynamoDbClient::new(Region::ApNortheast1);
    let mut input = PutItemInput::default();
    let mut entry = HashMap::new();
    entry.insert("id".to_string(), AttributeValue { s: Option::from(Uuid::new_v4().to_hyphenated().to_string()), ..Default::default() });
    entry.insert("name".to_string(), AttributeValue { s: Option::from(event.param), ..Default::default() });
    input.item = entry;
    input.table_name = "example".to_string();
    let result = client.put_item(input).await?;
    Ok(CustomResult { result: format!("it = '{:?}'", result) }) # 例としてDebugを返しているが、PutItemの場合resultには特に何もない
}