1. A method comprising: maintaining a repository of metadata, wherein the metadata repository comprises metadata associated with applications, metadata associated with content associated with the applications, and metadata associated with a cloud infrastructure environment in which the applications are deployable; and determining a deployment for a given application on a trusted infrastructure within the cloud infrastructure environment based on at least a subset of the metadata maintained in the metadata repository, wherein determining the deployment of the given application based on the subset of the metadata comprises mapping trust-based criteria associated with the given application with a given portion of infrastructure of the cloud infrastructure environment that satisfies the trust-based criteria; wherein the maintaining and determining steps are executed by one or more processing devices; wherein maintaining the repository of metadata comprises: obtaining information describing trust capabilities of respective portions of the cloud infrastructure environment; generating trust taxonomies for respective ones of the portions of the cloud infrastructure environment based on the obtained information; and storing the trust taxonomies for respective portions of the cloud infrastructure in the metadata repository as at least a portion of the metadata associated with the cloud infrastructure environment in which the applications are deployable; and wherein determining the deployment for the given application on the trusted infrastructure comprises: extracting a unique identifier for the given application in a platform-as-a-service layer of the cloud infrastructure environment, the platform-as-a-service layer being configured to abstract cloud infrastructure and to enable a user to deploy the given application in the given portion of the cloud infrastructure; providing the extracted identifier to a governed placement service, the governed placement service utilizing the extracted identifier as a key for accessing policies and schemas for the given application from the applications metadata and content metadata of the metadata repository; utilizing the policies and schemas to determine the trust-based criteria associated with the given application; discovering one or more portions of the cloud infrastructure environment that satisfy the trust-based criteria associated with the given application from the cloud infrastructure metadata in the metadata repository, the cloud infrastructure metadata comprising information describing trust capabilities of different portions of the cloud infrastructure environment; and selecting the given portion of the cloud infrastructure from the discovered one or more portions of the cloud infrastructure environment.