server: add config options, better outfile namesrustserver

e.g. - ability to log ip addresses of respondents - configurable bind address - reasonably sane defaults (hopefully) - survey name as part of output file names
author: stuebinm 2021-04-27 17:40:40 +0200
committer: stuebinm 2021-04-27 17:40:40 +0200
commit: e0c6f2cd7a2ef02fb9b7947816b54f3a43ef522d (patch)
tree: 8e5f1829d40e159086ac9aa4c2f248e8d633e110 /server/src/main.rs
parent: 445c3f73d77fe957c1663666df4fde852fd4de14 (diff)
1 files changed, 94 insertions, 27 deletions
diff --git a/server/src/main.rs b/server/src/main.rs
index ec2c77c..b718d57 100644
--- a/server/src/main.rs
+++ b/server/src/main.rs
@@ -1,36 +1,92 @@
 
 use hyper::service::{make_service_fn, service_fn};
 use hyper::{Body, Method, Request, Response, Server, StatusCode};
+use hyper::server::conn::AddrStream;
 use sha2::{Sha256, Digest};
 use std::io::Write;
+use std::convert::Infallible;
+use std::net::SocketAddr;
+use std::path::PathBuf;
+use structopt::StructOpt;
+
+
+
+#[derive(Debug, StructOpt, Clone)]
+#[structopt(about = "simple server that eats slightly better surveys.")]
+struct Settings {
+    #[structopt(short, long, help="log ip addresses of answers as part of their filename")]
+    log_ips: bool,
+    #[structopt(default_value="127.0.0.1:8000", help="address which the server should listen on")]
+    bind_address: SocketAddr,
+    #[structopt(parse(from_os_str), default_value=".", help="where to save incoming survey answers")]
+    out_path: PathBuf
+}
+
+
+async fn handle_survey(req: Request<Body>, remote_addr: &SocketAddr, settings: &Settings) -> Option<Response<Body>> {
+    let (parts, rawbody) = req.into_parts();
+    let body = hyper::body::to_bytes(rawbody).await.ok()?;
+    let survey = parts.headers.get("survey")?;
+
+    let hash = {
+        // we can use a hash of the content as filename;
+        // age ensures we won't have collisions even if
+        // two people handed in the same thing twice.
+        let mut hasher = Sha256::new();
+        hasher.update(body.clone());
+        hasher.finalize()
+    };
+
+    let mut filepath = settings.out_path.clone();
+    filepath.set_file_name(match settings.log_ips {
+        true => {
+            let filename = format!(
+                "answers-{}-{}-{:.20}.age",
+                survey.to_str().ok()?,
+                remote_addr.ip(),
+                hex::encode(hash)
+            );
+            println!(
+                "received survey response for survey {:?} from {}, saving to {}",
+                survey,
+                remote_addr.ip(),
+                filename
+            );
+            filename
+        },
+        false => {
+            let filename = format!(
+                "answers-{}-{:.20}.age",
+                survey.to_str().ok()?,
+                hex::encode(hash)
+            );
+            println!(
+                "received survey response for survey {:?}, saving to {}",
+                survey,
+                filename
+            );
+            filename
+        }
+    });
+
+    let mut file = std::fs::File::create(filepath).ok()?;
+    file.write_all(&body).unwrap();
+
+    Some(Response::new(
+        "thanks for handing in these answers!\n".into()
+    ))
+}
 
 /// This is our service handler. It receives a Request, routes on its
 /// path, and returns a Future of a Response.
-async fn echo(req: Request<Body>) -> Result<Response<Body>, hyper::Error> {
+async fn server(req: Request<Body>, remote_addr: &SocketAddr, settings: &Settings) -> Result<Response<Body>, Infallible> {
     match (req.method(), req.uri().path()) {
-        // Serve some instructions at /
-        (&Method::GET, "/") => Ok(Response::new(Body::from(
-            "Try POSTing data to /echo such as: `curl localhost:8000/echo -XPOST -d 'hello world'`",
-        ))),
-
-        // Simply echo the body back to the client.
-        (&Method::POST, "/echo") => Ok(Response::new(req.into_body())),
 
         (&Method::POST, "/survey") => {
-            let full_body = hyper::body::to_bytes(req.into_body()).await?;
-            let mut hasher = Sha256::new();
-            hasher.update(full_body.clone());
-            let hash = hasher.finalize();
-
-            let mut file = std::fs::File::create(
-                format!("answers-{}.age", hex::encode(hash))
-            ).unwrap();
-
-            file.write_all(&full_body).unwrap();
-            println!("got hash: {:?}", hash);
-            Ok(Response::new(
-                "thanks for hading in these answers!".into()
-            ))
+            match handle_survey(req, remote_addr, settings).await {
+                Some(response) => Ok(response),
+                None => Ok(Response::new("Something went wrong\n".into()))
+            }
         }
 
         // Return the 404 Not Found for other routes.
@@ -46,17 +102,28 @@ async fn echo(req: Request<Body>) -> Result<Response<Body>, hyper::Error> {
 
 #[tokio::main]
 async fn main() -> Result<(), Box<dyn std::error::Error + Send + Sync>> {
-    let addr = ([127, 0, 0, 1], 8000).into();
 
+    // this is a memory leak of constant size, to avoid the borrow checker
+    let opt: &'static Settings = Box::leak(
+        Box::new(Settings::from_args())
+    );
+
+    // I have no idea what's wrong here ...
+    // look at https://docs.rs/hyper/0.14.7/hyper/service/fn.make_service_fn.html
     let service = make_service_fn(
-        |_| async {
-            Ok::<_, hyper::Error>(service_fn(echo))
+        |socket: &AddrStream|  {
+            let remote_addr = socket.remote_addr();
+            async move {
+                Ok::<_, Infallible>(service_fn(move |req: Request<Body>| async move {
+                    server(req, &remote_addr, &opt).await
+                }))
+            }
         }
     );
 
-    let server = Server::bind(&addr).serve(service);
+    let server = Server::bind(&opt.bind_address).serve(service);
 
-    println!("Listening on http://{}", addr);
+    println!("Listening on http://{}", opt.bind_address);
 
     server.await?;
author	stuebinm	2021-04-27 17:40:40 +0200
committer	stuebinm	2021-04-27 17:40:40 +0200
commit	e0c6f2cd7a2ef02fb9b7947816b54f3a43ef522d (patch)
tree	8e5f1829d40e159086ac9aa4c2f248e8d633e110 /server/src/main.rs
parent	445c3f73d77fe957c1663666df4fde852fd4de14 (diff)