Prometheus comes with several discovery integrations available out of the box. These cover most of the mainstream data sources for application and machine inventories, such as public and private cloud compute APIs, VM and container orchestration systems, standalone service registration and discovery systems, among others. For those discovery mechanisms that aren't directly supported by Prometheus, integration can be done through a generic discovery system using the filesystem and some glue code, as we'll see later in this chapter.

Every integration works in the same way – by setting all the discovered addresses as targets and their associated metadata as temporary labels (not persisted without some relabeling to keep them). For each discovered target, the __address__ label is usually set to the service address and...