# Smithy Rust Server SDK examples

This folder contains some example services showcasing Smithy Rust Server SDK,
also known as the Rust service framework, capabilities and to run benchmarks.

Three server implementations are available:

- `/pokemon-service`, a HTTP server demonstrating [middleware] and [extractors].
- `/pokemon-service-tls`, a HTTPS server. This server can do
   its own TLS negotiation, rather than relying on a load balancer.
- `/pokemon-service-lambda`, a server that can be deployed onto AWS Lambda.

These servers, and their clients, are generated using smithy-rs. You're invited
to benchmark the performance of these servers to see whether smithy-rs might be
a suitable choice for implementing your web service.

[middleware]: https://awslabs.github.io/smithy-rs/design/server/middleware.html
[extractors]: https://awslabs.github.io/smithy-rs/design/server/from_parts.html


## Pre-requisites

You will need install Java 11 to run the smithy-rs code generator and an
installation of Rust, including `cargo`, to compile the generated code.

(Optional) The [Cargo Lambda](https://cargo-lambda.info/) sub-command for
`cargo` is required to support the AWS Lambda integration.


## Building

Since these examples require both the server and client SDK to be code-generated
from their [model](/codegen-server-test/model/pokemon.smithy), a Makefile is
provided to build and run the service. Just run `make` to prepare the first
build.

Once the example has been built successfully the first time, idiomatic `cargo`
can be used directly.

### Make targets:

- `codegen`: generates the Pokémon service crates (default)
- `build`: compiles the generated client and server
- `clean`: deletes build artifacts
- `clippy`: lints the code
- `distclean`: delete generated code and build artifacts
- `doc-open`: builds and opens the rustdoc documentation
- `lambda_invoke`: invokes a running server
- `lambda_watch`: runs the service on an emulated AWS Lambda environment
- `run`: runs the Pokémon service
- `test`: runs integration and unit tests


## Running services

To run one of the three server implementations locally, provide the appropriate
service name to the `--bin` flag:

```bash
cargo run --bin pokemon-service[(-lambda|-tls)]
```

CLI arguments can be passed to the server binaries by adding them after `--`.
For example, to see a service's help information, use the following:

```bash
cargo run --bin <service> -- --help
```

## Testing

The `/pokemon-test*/tests` folders provide integration tests involving the
generated clients.

They can be invoked with `cargo test`. This will spawn each service in turn
and run some integration tests against it. Use `-p <package>` to filter by
package.

More info can be found in the `tests` folder of each package.


## Benchmarking

Servers running locally (see "Running services") can be benchmarked with any
load testing tool, such as Artillery or `wrk`.

Please see [BENCHMARKS.md](/examples/BENCHMARKS.md) for benchmarking results
produced by the smithy-rs team.
