Generate a Client method for Dropshot websocket channels

Generated methods return `ResponseValue<reqwest::Upgrade`, which may be
passed to a websocket protocol implementation such as
`tokio_tungstenite::WebSocketStream::from_raw_stream(rv.into_inner(), ...)`
for the purpose of implementing against the raw websocket connection, but
may later be extended as a generic to allow higher-level channel message
definitions.

Per the changelog, consumers will need to depend on reqwest from git until
such time upstream cuts a new crates.io release:
```
reqwest = {
    git = "https://github.com/seanmonstar/reqwest",
    rev = "6ceb23958c8b6d7f1d8ee093f0ad73184d133d40",
    features = ["json", "stream"]
}
```

Author: lif

CHANGELOG.adoc

@@ -20,6 +20,7 @@ https://github.com/oxidecomputer/progenitor/compare/v0.1.1\...HEAD[Full list of
 * Derive `Debug` for `Client` and builders for the various operations (#145)
 * Builders for `struct` types (#171)
 * Add a prelude that include the `Client` and any extension traits (#176)
+* Add support for upgrading connections, which requires a version bump to reqwest. (#183)
 
 == 0.1.1 (released 2022-05-13)
 

Cargo.lock

@@ -7,7 +7,8 @@ edition = "2021"
 [dependencies]
 chrono = { version = "0.4", features = ["serde"] }
 progenitor-client = { path = "../progenitor-client" }
-reqwest = { version = "0.11", features = ["json", "stream"] }
+reqwest = { git = "https://github.com/seanmonstar/reqwest", rev = "6ceb23958c8b6d7f1d8ee093f0ad73184d133d40", features = ["json", "stream"] }
+#reqwest = { version = "0.11", features = ["json", "stream"] }
 serde = { version = "1.0", features = ["derive"] }
 uuid = { version = "1.0", features = ["serde", "v4"] }
 

example-build/Cargo.toml

@@ -7,7 +7,8 @@ edition = "2021"
 [dependencies]
 chrono = { version = "0.4", features = ["serde"] }
 progenitor = { path = "../progenitor" }
-reqwest = { version = "0.11", features = ["json", "stream"] }
+reqwest = { git = "https://github.com/seanmonstar/reqwest", rev = "6ceb23958c8b6d7f1d8ee093f0ad73184d133d40", features = ["json", "stream"] }
+#reqwest = { version = "0.11", features = ["json", "stream"] }
 schemars = { version = "0.8.10", features = ["uuid1"] }
 serde = { version = "1.0", features = ["derive"] }
 uuid = { version = "1.0", features = ["serde", "v4"] }

example-macro/Cargo.toml

@@ -10,7 +10,10 @@ description = "An OpenAPI client generator - client support"
 bytes = "1.2.1"
 futures-core = "0.3.24"
 percent-encoding = "2.1"
-reqwest = { version = "0.11", default-features = false, features = ["json", "stream"] }
+reqwest = { git = "https://github.com/seanmonstar/reqwest", rev = "6ceb23958c8b6d7f1d8ee093f0ad73184d133d40", features = ["json", "stream"] }
+#reqwest = { version = "0.11", default-features = false, features = ["json", "stream"] }
 serde = "1.0"
 serde_json = "1.0"
 serde_urlencoded = "0.7.1"
+base64 = "0.13"
+rand = "0.8"

progenitor-client/Cargo.toml

@@ -76,6 +76,30 @@ impl<T: DeserializeOwned> ResponseValue<T> {
     }
 }
 
+impl ResponseValue<reqwest::Upgraded> {
+    #[doc(hidden)]
+    pub async fn upgrade<E: std::fmt::Debug>(
+        response: reqwest::Response,
+    ) -> Result<Self, Error<E>> {
+        let status = response.status();
+        let headers = response.headers().clone();
+        if status == reqwest::StatusCode::SWITCHING_PROTOCOLS {
+            let inner = response
+                .upgrade()
+                .await
+                .map_err(Error::InvalidResponsePayload)?;
+
+            Ok(Self {
+                inner,
+                status,
+                headers,
+            })
+        } else {
+            Err(Error::UnexpectedResponse(response))
+        }
+    }
+}
+
 impl ResponseValue<ByteStream> {
     #[doc(hidden)]
     pub fn stream(response: reqwest::Response) -> Self {
@@ -377,3 +401,8 @@ impl<E> RequestBuilderExt<E> for RequestBuilder {
             })?))
     }
 }
+
+#[doc(hidden)]
+pub fn generate_websocket_key() -> String {
+    base64::encode(rand::random::<[u8; 16]>())
+}

progenitor-client/src/progenitor_client.rs

@@ -26,6 +26,8 @@ pub enum Error {
     UnexpectedFormat(String),
     #[error("invalid operation path {0}")]
     InvalidPath(String),
+    #[error("invalid dropshot extension use: {0}")]
+    InvalidExtension(String),
     #[error("internal error {0}")]
     InternalError(String),
 }
@@ -213,7 +215,12 @@ impl Generator {
         let file = quote! {
             // Re-export ResponseValue and Error since those are used by the
             // public interface of Client.
-            pub use progenitor_client::{ByteStream, Error, ResponseValue};
+            pub use progenitor_client::{
+                ByteStream,
+                Error,
+                ResponseValue,
+                generate_websocket_key
+            };
             #[allow(unused_imports)]
             use progenitor_client::{encode_path, RequestBuilderExt};
 
@@ -319,6 +326,7 @@ impl Generator {
                 #[allow(unused_imports)]
                 use super::{
                     encode_path,
+                    generate_websocket_key,
                     ByteStream,
                     Error,
                     RequestBuilderExt,
@@ -358,11 +366,14 @@ impl Generator {
                 #[allow(unused_imports)]
                 use super::{
                     encode_path,
+                    generate_websocket_key,
                     ByteStream,
                     Error,
                     RequestBuilderExt,
                     ResponseValue,
                 };
+                #[allow(unused_imports)]
+                use std::convert::TryInto;
 
                 #(#builder_struct)*