Usable declarative configuration specification and validation for applications, systems, and cloud
is increasingly difficult. These stacks comprise multiple microservices which are deployed across a combination of containers and hosts (VMs, physical machines) in a cloud or a data center. The existing approaches for detecting misconfiguration, whether rule-based or inference, are highly specialized (e.g., security only), cumbersome to write and maintain, geared towards a host (instead of container images), and can result into false-positives or false-negatives. This paper introduces configuration validation language (CVL), a declarative language for writing rules to detect misconfigurations that can, for instance, impact security, performance, functionality. We have built a system, ConfigValidator, which applies the CVL rules across a multitude of environments such as Docker images, running containers, host, and cloud. The system is running in production and has scanned thousands of Docker images and running containers for identifying misconfigurations.