Plumb through reading the FASTLY_KEY env variable to compute modules

lib/src/component/mod.rs

@@ -2,7 +2,7 @@ use {crate::linking::ComponentCtx, wasmtime::component};
 
 component::bindgen!({
     path: "wit",
-    world: "fastly:api/compute",
+    world: "fastly:viceroy/compute",
     async: true,
     with: {
         "fastly:api/uap/user-agent": uap::UserAgent,
@@ -57,6 +57,7 @@ pub fn link_host_functions(linker: &mut component::Linker<ComponentCtx>) -> anyh
     fastly::api::secret_store::add_to_linker(linker, |x| x.session())?;
     fastly::api::types::add_to_linker(linker, |x| x.session())?;
     fastly::api::uap::add_to_linker(linker, |x| x.session())?;
+    fastly::api::viceroy_env::add_to_linker(linker, |x| x.session())?;
 
     Ok(())
 }
@@ -78,3 +79,4 @@ pub mod purge;
 pub mod secret_store;
 pub mod types;
 pub mod uap;
+pub mod viceroy_env;

lib/src/component/viceroy_env.rs

@@ -0,0 +1,8 @@
+use {super::fastly::api::viceroy_env, crate::session::Session};
+
+#[async_trait::async_trait]
+impl viceroy_env::Host for Session {
+    async fn fastly_key(&mut self) -> Result<String, ()> {
+        self.fastly_key_read().ok_or(())
+    }
+}

lib/src/execute.rs

@@ -89,6 +89,8 @@ pub struct ExecuteCtx {
     object_store: ObjectStores,
     /// The secret stores for this execution.
     secret_stores: Arc<SecretStores>,
+    /// The FASTLY_KEY read in from the environment
+    fastly_key: Arc<Option<String>>,
     // `Arc` for the two fields below because this struct must be `Clone`.
     epoch_increment_thread: Option<Arc<JoinHandle<()>>>,
     epoch_increment_stop: Arc<AtomicBool>,
@@ -189,6 +191,7 @@ impl ExecuteCtx {
                 engine_clone.increment_epoch();
             }
         })));
+        let fastly_key = std::env::var("FASTLY_KEY").ok();
 
         Ok(Self {
             engine,
@@ -204,6 +207,7 @@ impl ExecuteCtx {
             next_req_id: Arc::new(AtomicU64::new(0)),
             object_store: ObjectStores::new(),
             secret_stores: Arc::new(SecretStores::new()),
+            fastly_key: Arc::new(fastly_key),
             epoch_increment_thread,
             epoch_increment_stop,
             guest_profile_path: Arc::new(guest_profile_path),
@@ -416,6 +420,7 @@ impl ExecuteCtx {
             self.config_path.clone(),
             self.object_store.clone(),
             self.secret_stores.clone(),
+            self.fastly_key.clone(),
         );
 
         let guest_profile_path = self.guest_profile_path.as_deref().map(|path| {
@@ -560,6 +565,7 @@ impl ExecuteCtx {
             self.config_path.clone(),
             self.object_store.clone(),
             self.secret_stores.clone(),
+            self.fastly_key.clone(),
         );
 
         if let Instance::Component(_) = self.instance_pre.as_ref() {

lib/src/session.rs

@@ -126,6 +126,8 @@ pub struct Session {
     config_path: Arc<Option<PathBuf>>,
     /// The ID for the client request being processed.
     req_id: u64,
+    /// FASTLY_KEY read in from the environment
+    fastly_key: Arc<Option<String>>,
 }
 
 impl Session {
@@ -144,6 +146,7 @@ impl Session {
         config_path: Arc<Option<PathBuf>>,
         object_store: ObjectStores,
         secret_stores: Arc<SecretStores>,
+        fastly_key: Arc<Option<String>>,
     ) -> Session {
         let (parts, body) = req.into_parts();
         let downstream_req_original_headers = parts.headers.clone();
@@ -179,6 +182,7 @@ impl Session {
             secrets_by_name: PrimaryMap::new(),
             config_path,
             req_id,
+            fastly_key,
         }
     }
 
@@ -839,6 +843,12 @@ impl Session {
         &self.secret_stores
     }
 
+    // ----- FASTLY_KEY (env var) -----
+
+    pub fn fastly_key_read(&self) -> Option<String> {
+        self.fastly_key.as_ref().as_ref().cloned()
+    }
+
     // ----- Pending Requests API -----
 
     /// Insert a [`PendingRequest`] into the session.

lib/wit/deps/fastly/compute.wit

@@ -1065,6 +1065,10 @@ interface reactor {
   serve: func(req: request-handle, body: body-handle) -> result;
 }
 
+interface viceroy-env {
+	fastly-key: func() -> result<string>;
+}
+
 world compute {
     import wasi:clocks/[email protected];
     import wasi:clocks/[email protected];

lib/wit/viceroy.wit

@@ -2,4 +2,5 @@ package fastly:viceroy;
 
 world compute {
 	include fastly:api/compute;
+	import fastly:api/viceroy-env;
 }