Increased heterogeneity of physical resources has had positive and negative effects in Internet of Things (IoT) through the existence of edge computing. As a result, there has been a need for effective dynamic management of IoT, cloud and edge resources, in order to address the existence of low-level constraints during resource migration. Nevertheless, the explosion of IoT devices and data has allowed orchestration of microservices to adopt an opportunistic approach to how applications and services are deployed in the edge in IoT platform. A notable approach has been osmotic computing that allows resources from a federated cloud to be able to diffuse from an ecosystem of higher solute (network properties and entities) concentration to solvent (applications, layered interfaces and services). We posit that, while computing resources and applications are able to move from the federated environment, to the cloud deployable models, to the edge, then to IoT ecosystem, there is a higher chance of susceptibility of threats and attacks that may be directed to the emerging edge applications/data due to dynamic emergent configurations. This paper proposes a 5-layer opportunistic architecture that adds security metrics across different levels of osmotic computing paradigm. The proposed 5-layer security architecture addresses the need for autonomously securing resources-edge computation, edge storage and emerging edge configurations as the computing resources move to a higher solute in heterogenous edge and cloud datacenters across IoT devices. This has been achieved by proposing security metrics that address the prevailing challenge with a degree of certainty.