sausage-plugin part 2: import! with typed clients (sausage_interface::client_rs), TCP endpoints with rpc.endpoint, examples

Part 1 fixes: complete stdout writes, buffered stdin, Rust type names
in schemas, enum variant docs, -32603 for serde errors in handlers,
crate docs and modules. End-to-end check of a generated consumer through
a fake core.

examples/secrets/src/main.rs

@@ -0,0 +1,46 @@
+//! Keep a process-local vault behind a fixed endpoint at `/run/secrets`.
+//! Start `secrets.serve` as a detached boot service. Its memory lasts until process exit.
+use sausage_plugin::{Ctx, Result, listen, rpc, schema};
+use std::{cell::RefCell, collections::BTreeMap, rc::Rc};
+struct Secrets;
+#[rpc(endpoints(vault=Vault))]
+impl Secrets {
+    /// Open the in-memory vault and publish its endpoint.
+    async fn serve(&self) -> Result<()> {
+        listen("/run/secrets", Rc::new(Vault::default())).await
+    }
+}
+#[derive(Default)]
+struct Vault {
+    entries: RefCell<BTreeMap<String, String>>,
+}
+/// The name and value of a secret.
+#[schema]
+struct PutParams {
+    /// The unique name within this vault.
+    name: String,
+    /// The text to store until process exit.
+    value: String,
+}
+/// The name of a secret to read.
+#[schema]
+struct GetParams {
+    /// The unique name within this vault.
+    name: String,
+}
+#[rpc]
+impl Vault {
+    /// Store a secret and report its name to the caller.
+    fn put(&self, ctx: &Ctx, p: PutParams) -> Result<()> {
+        ctx.notify("stored", sausage_plugin::serde_json::json!({"name":p.name}))?;
+        self.entries.borrow_mut().insert(p.name, p.value);
+        Ok(())
+    }
+    /// Read a secret, or return null when its name is absent.
+    fn get(&self, p: GetParams) -> Result<Option<String>> {
+        Ok(self.entries.borrow().get(&p.name).cloned())
+    }
+}
+fn main() {
+    sausage_plugin::run(Secrets)
+}