Alex, a cloud security engineer working in Eyecloud Inc. is tasked with isolating applications from the underlying infrastructure and stimulating communication via well-defined channels. For this purpose, he used an open-source technology that helped him in developing, packaging, and running applications; further, the technology provides PaaS through OS-level virtualization, delivers containerized software packages, and promotes fast software delivery.
What is the cloud technology employed by Alex in the above scenario?