IBM DataPower doesn't support validating REST API calls against a swagger document out-of-the-box (Unless you have IBM API Connect). This project exposes REST APIs using swaggers on a sinle Multi Protcol Gateway.
This means you can simply upload your swaggers to the designated directory and get it exposed and schema validated immediately.
You can start by building the docker image and run it.
git clone https://github.com/dorser/dp-swagger-proxy.git
cd dp-swagger-proxy
docker build -t dorser/apigw:1.0 .
docker start --name apigw -p 15000:15000 -e DATAPOWER_ACCEPT_LICENSE=true dorser/apigw:1.0