feat(agent): expose HTTP debug server over tailnet API (#12582)

codersdk/workspaceagentconn.go

@@ -356,6 +356,22 @@ func (c *WorkspaceAgentConn) ListeningPorts(ctx context.Context) (WorkspaceAgent
 	return resp, json.NewDecoder(res.Body).Decode(&resp)
 }
 
+// DebugMagicsock makes a request to the workspace agent's magicsock debug endpoint.
+func (c *WorkspaceAgentConn) DebugMagicsock(ctx context.Context) ([]byte, error) {
+	ctx, span := tracing.StartSpan(ctx)
+	defer span.End()
+	res, err := c.apiRequest(ctx, http.MethodGet, "/debug/magicsock", nil)
+	if err != nil {
+		return nil, xerrors.Errorf("do request: %w", err)
+	}
+	defer res.Body.Close()
+	bs, err := io.ReadAll(res.Body)
+	if err != nil {
+		return nil, xerrors.Errorf("read response body: %w", err)
+	}
+	return bs, nil
+}
+
 // apiRequest makes a request to the workspace agent's HTTP API server.
 func (c *WorkspaceAgentConn) apiRequest(ctx context.Context, method, path string, body io.Reader) (*http.Response, error) {
 	ctx, span := tracing.StartSpan(ctx)