feat: derp mesh network & derper cli & config cleanup (#1130)

* set up `MeshClients` & use it in `derp::http::Server` to mesh with other derp servers

* Clean up Derper CLI

To run the derper in dev mode, use the `--dev` flag.

All other configuration must be set using a config file.

Generate a default config file by running the derper with the
`--config-path` flag and supplying a path.

Note: you can use a config file along with the `--dev` flag, but it will
ignore any TLS specific configuration & only run the derper using HTTP.

* fix conn tests test: ensure we dial via tls

iroh-net/src/hp/derp/client.rs

@@ -52,6 +52,8 @@ pub struct InnerClient {
     writer_task: Mutex<Option<JoinHandle<Result<()>>>>,
     /// The reader connected to the server
     reader: Mutex<tokio::io::ReadHalf<Box<dyn Io + Send + Sync + 'static>>>,
+    /// Public key of the server we are connected to
+    server_public_key: PublicKey,
 }
 
 // TODO: I believe that any of these that error should actually trigger a shut down of the client
@@ -285,6 +287,10 @@ impl Client {
             }
         }
     }
+
+    pub fn server_public_key(self) -> PublicKey {
+        self.inner.server_public_key.clone()
+    }
 }
 
 /// The kinds of messages we can send to the Server
@@ -482,7 +488,7 @@ where
 
     pub async fn build(mut self, buf: Option<Bytes>) -> Result<Client> {
         // exchange information with the server
-        let (_, rate_limiter) = self.server_handshake(buf).await?;
+        let (server_public_key, rate_limiter) = self.server_handshake(buf).await?;
 
         // create task to handle writing to the server
         let (writer_sender, writer_recv) = mpsc::channel(PER_CLIENT_SEND_QUEUE_DEPTH);
@@ -502,6 +508,7 @@ where
                 writer_channel: writer_sender,
                 writer_task: Mutex::new(Some(writer_task)),
                 reader: Mutex::new(self.reader),
+                server_public_key,
             }),
         };
 

iroh-net/src/hp/derp/http.rs

@@ -1,7 +1,9 @@
 mod client;
+mod mesh_clients;
 mod server;
 
 pub use self::client::{Client, ClientBuilder, ClientError};
+pub use self::mesh_clients::MeshAddrs;
 pub use self::server::{Server, ServerBuilder, TlsAcceptor, TlsConfig};
 
 pub(crate) const HTTP_UPGRADE_PROTOCOL: &str = "iroh derp http";
@@ -139,10 +141,13 @@ mod tests {
         if let Some(url) = server_url {
             client = client.server_url(url);
         }
-        let client = client.new_region(key.clone(), move || {
-            let region = region.clone();
-            Box::pin(async move { Some(region) })
-        });
+        let client = client
+            .get_region(move || {
+                let region = region.clone();
+                Box::pin(async move { Some(region) })
+            })
+            .build(key.clone())
+            .expect("won't fail if you supply a `get_region`");
         let public_key = key.public_key();
         let (received_msg_s, received_msg_r) = tokio::sync::mpsc::channel(10);
         let client_reader = client.clone();