Run npm install in the middleware folder to install the packages (libraries) specified in the package.json and their dependencies. You should see the packages downloaded to the node_modules folder.

A cleaner way of installing dependencies and configuring the middleware for regular operation is automated building using Makefile. You can simply run make in the middleware folder; see Chapter 8, Agility In A Blockchain Network, for more details on setting up and building your development and testing environment.