Update pageserver OpenAPI spec with missing attach/detach methods (#1463)

We have these methods for some time in the API, so mentioning them in the
spec could be useful for console (see zenithdb/console#867), as we generate
pageserver HTTP API golang client there.

pageserver/src/http/openapi_spec.yml

@@ -18,7 +18,7 @@ paths:
               schema:
                 type: object
                 required:
-                - id
+                  - id
                 properties:
                   id:
                     type: integer
@@ -122,6 +122,110 @@ paths:
             application/json:
               schema:
                 $ref: "#/components/schemas/Error"
+
+
+  /v1/tenant/{tenant_id}/timeline/{timeline_id}/attach:
+    parameters:
+      - name: tenant_id
+        in: path
+        required: true
+        schema:
+          type: string
+          format: hex
+      - name: timeline_id
+        in: path
+        required: true
+        schema:
+          type: string
+          format: hex
+    post:
+      description: Attach remote timeline
+      responses:
+        "200":
+          description: Timeline attaching scheduled
+        "400":
+          description: Error when no tenant id found in path or no timeline id
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/Error"
+        "401":
+          description: Unauthorized Error
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/UnauthorizedError"
+        "403":
+          description: Forbidden Error
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/ForbiddenError"
+        "404":
+          description: Timeline not found
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/NotFoundError"
+        "409":
+          description: Timeline download is already in progress
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/ConflictError"
+        "500":
+          description: Generic operation error
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/Error"
+
+
+  /v1/tenant/{tenant_id}/timeline/{timeline_id}/detach:
+    parameters:
+      - name: tenant_id
+        in: path
+        required: true
+        schema:
+          type: string
+          format: hex
+      - name: timeline_id
+        in: path
+        required: true
+        schema:
+          type: string
+          format: hex
+    post:
+      description: Detach local timeline
+      responses:
+        "200":
+          description: Timeline detached
+        "400":
+          description: Error when no tenant id found in path or no timeline id
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/Error"
+        "401":
+          description: Unauthorized Error
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/UnauthorizedError"
+        "403":
+          description: Forbidden Error
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/ForbiddenError"
+        "500":
+          description: Generic operation error
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/Error"
+
+
   /v1/tenant/{tenant_id}/timeline/:
     parameters:
       - name: tenant_id
@@ -179,7 +283,7 @@ paths:
           content:
             application/json:
               schema:
-                $ref: "#/components/schemas/AlreadyExistsError"
+                $ref: "#/components/schemas/ConflictError"
         "500":
           description: Generic operation error
           content:
@@ -260,7 +364,7 @@ paths:
           content:
             application/json:
               schema:
-                $ref: "#/components/schemas/AlreadyExistsError"
+                $ref: "#/components/schemas/ConflictError"
         "500":
           description: Generic operation error
           content:
@@ -354,14 +458,21 @@ components:
       properties:
         msg:
           type: string
-    AlreadyExistsError:
+    ForbiddenError:
       type: object
       required:
         - msg
       properties:
         msg:
           type: string
-    ForbiddenError:
+    NotFoundError:
+      type: object
+      required:
+        - msg
+      properties:
+        msg:
+          type: string
+    ConflictError:
       type: object
       required:
         - msg

pageserver/src/http/routes.rs

@@ -220,6 +220,7 @@ async fn timeline_attach_handler(request: Request<Body>) -> Result<Response<Body
     let span = tokio::task::spawn_blocking(move || {
         let entered = span.entered();
         if tenant_mgr::get_timeline_for_tenant_load(tenant_id, timeline_id).is_ok() {
+            // TODO: maybe answer with 309 Not Modified here?
             anyhow::bail!("Timeline is already present locally")
         };
         Ok(entered.exit())
@@ -235,10 +236,10 @@ async fn timeline_attach_handler(request: Request<Body>) -> Result<Response<Body
             tenant_id,
             timeline_id,
         })
-        .ok_or_else(|| ApiError::BadRequest("Unknown remote timeline".to_string()))?;
+        .ok_or_else(|| ApiError::NotFound("Unknown remote timeline".to_string()))?;
 
     if index_entry.get_awaits_download() {
-        return Err(ApiError::NotFound(
+        return Err(ApiError::Conflict(
             "Timeline download is already in progress".to_string(),
         ));
     }

zenith_utils/src/http/error.rs

@@ -17,6 +17,9 @@ pub enum ApiError {
     #[error("NotFound: {0}")]
     NotFound(String),
 
+    #[error("Conflict: {0}")]
+    Conflict(String),
+
     #[error(transparent)]
     InternalServerError(#[from] anyhow::Error),
 }
@@ -42,6 +45,9 @@ impl ApiError {
             ApiError::NotFound(_) => {
                 HttpErrorBody::response_from_msg_and_status(self.to_string(), StatusCode::NOT_FOUND)
             }
+            ApiError::Conflict(_) => {
+                HttpErrorBody::response_from_msg_and_status(self.to_string(), StatusCode::CONFLICT)
+            }
             ApiError::InternalServerError(err) => HttpErrorBody::response_from_msg_and_status(
                 err.to_string(),
                 StatusCode::INTERNAL_SERVER_ERROR,