[wicketd] add stub API for fetching artifacts (#1998)

Add a basic stub API for fetching artifacts, and update the OpenAPI
schema.

The implementation hasn't been filled out yet.

openapi/wicketd.json

@@ -10,6 +10,60 @@
     "version": "0.0.1"
   },
   "paths": {
+    "/artifacts/{name}/{version}/{hash}": {
+      "get": {
+        "summary": "Fetch an artifact from the in-memory cache.",
+        "operationId": "get_artifact",
+        "parameters": [
+          {
+            "in": "path",
+            "name": "hash",
+            "description": "A hash of the artifact. TODO: is there a hash type?",
+            "required": true,
+            "schema": {
+              "type": "string"
+            },
+            "style": "simple"
+          },
+          {
+            "in": "path",
+            "name": "name",
+            "description": "The artifact's name.",
+            "required": true,
+            "schema": {
+              "type": "string"
+            },
+            "style": "simple"
+          },
+          {
+            "in": "path",
+            "name": "version",
+            "description": "The version of the artifact.",
+            "required": true,
+            "schema": {
+              "type": "string"
+            },
+            "style": "simple"
+          }
+        ],
+        "responses": {
+          "200": {
+            "description": "",
+            "content": {
+              "*/*": {
+                "schema": {}
+              }
+            }
+          },
+          "4XX": {
+            "$ref": "#/components/responses/Error"
+          },
+          "5XX": {
+            "$ref": "#/components/responses/Error"
+          }
+        }
+      }
+    },
     "/inventory": {
       "get": {
         "summary": "A status endpoint used to report high level information known to wicketd.",

wicketd/src/artifacts.rs

@@ -0,0 +1,40 @@
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at https://mozilla.org/MPL/2.0/.
+
+// Copyright 2022 Oxide Computer Company
+
+use hyper::body::Bytes;
+use schemars::JsonSchema;
+use serde::Deserialize;
+use slog::Logger;
+
+/// Path parameters for Silo requests
+#[derive(Clone, Debug, Deserialize, JsonSchema)]
+#[allow(dead_code)]
+pub(crate) struct ArtifactId {
+    /// The artifact's name.
+    pub(crate) name: String,
+
+    /// The version of the artifact.
+    pub(crate) version: String,
+}
+
+/// The artifact store, used to cache artifacts.
+pub struct ArtifactStore {
+    log: Logger,
+    // TODO: implement this
+}
+
+impl ArtifactStore {
+    pub(crate) fn new(log: &Logger) -> Self {
+        let log = log.new(slog::o!("component" => "wicketd artifact store"));
+        Self { log }
+    }
+
+    pub(crate) fn get_artifact(&self, id: &ArtifactId) -> Option<Bytes> {
+        slog::debug!(self.log, "Artifact requested (this is a stub implementation which always 404s): {:?}", id);
+        // TODO: implement this
+        None
+    }
+}

wicketd/src/context.rs

@@ -4,9 +4,10 @@
 
 //! User provided dropshot server context
 
-use crate::MgsHandle;
+use crate::{artifacts::ArtifactStore, MgsHandle};
 
 /// Shared state used by API handlers
 pub struct ServerContext {
+    pub artifact_store: ArtifactStore,
     pub mgs_handle: MgsHandle,
 }

wicketd/src/http_entrypoints.rs

@@ -4,12 +4,16 @@
 
 //! HTTP entrypoint functions for wicketd
 
+use crate::artifacts::ArtifactId;
 use crate::RackV1Inventory;
 use dropshot::endpoint;
 use dropshot::ApiDescription;
+use dropshot::FreeformBody;
 use dropshot::HttpError;
 use dropshot::HttpResponseOk;
+use dropshot::Path;
 use dropshot::RequestContext;
+use hyper::Body;
 use std::sync::Arc;
 
 use crate::ServerContext;
@@ -22,6 +26,7 @@ pub fn api() -> WicketdApiDescription {
         api: &mut WicketdApiDescription,
     ) -> Result<(), String> {
         api.register(get_inventory)?;
+        api.register(get_artifact)?;
         Ok(())
     }
 
@@ -53,3 +58,22 @@ async fn get_inventory(
         }
     }
 }
+
+/// Fetch an artifact from the in-memory cache.
+#[endpoint {
+    method = GET,
+    path = "/artifacts/{name}/{version}"
+}]
+async fn get_artifact(
+    rqctx: Arc<RequestContext<ServerContext>>,
+    path: Path<ArtifactId>,
+) -> Result<HttpResponseOk<FreeformBody>, HttpError> {
+    match rqctx.context().artifact_store.get_artifact(&path.into_inner()) {
+        Some(bytes) => Ok(HttpResponseOk(Body::from(bytes).into())),
+        None => {
+            Err(HttpError::for_not_found(None, "Artifact not found".into()))
+        }
+    }
+}
+
+// TODO: hash verification/fetch artifact by hash?

wicketd/src/lib.rs

@@ -2,12 +2,14 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at https://mozilla.org/MPL/2.0/.
 
+mod artifacts;
 mod config;
 mod context;
 mod http_entrypoints;
 mod inventory;
 mod mgs;
 
+use artifacts::ArtifactStore;
 pub use config::Config;
 pub(crate) use context::ServerContext;
 pub use inventory::{RackV1Inventory, SpInventory};
@@ -58,6 +60,8 @@ pub async fn run_server(config: Config, args: Args) -> Result<(), String> {
         ..Default::default()
     };
 
+    let artifact_store = ArtifactStore::new(&log);
+
     let mgs_manager = MgsManager::new(&log, config.mgs_addr);
     let mgs_handle = mgs_manager.get_handle();
     tokio::spawn(async move {
@@ -67,7 +71,7 @@ pub async fn run_server(config: Config, args: Args) -> Result<(), String> {
     let server = dropshot::HttpServerStarter::new(
         &dropshot_config,
         http_entrypoints::api(),
-        ServerContext { mgs_handle },
+        ServerContext { artifact_store, mgs_handle },
         &log.new(o!("component" => "dropshot (wicketd)")),
     )
     .map_err(|err| format!("initializing http server: {}", err))?