OOM Developer Guide
ONAP consists of a large number of components, each of which are substantial projects within themselves, which results in a high degree of complexity in deployment and management. To cope with this complexity the ONAP Operations Manager (OOM) uses a Helm model of ONAP - Helm being the primary management system for Kubernetes container systems - to drive all user driven life-cycle management operations. The Helm model of ONAP is composed of a set of hierarchical Helm charts that define the structure of the ONAP components and the configuration of these components. These charts are fully parameterized such that a single environment file defines all of the parameters needed to deploy ONAP. A user of ONAP may maintain several such environment files to control the deployment of ONAP in multiple environments such as development, pre-production, and production.
Linux containers allow for an application and all of its operating system dependencies to be packaged and deployed as a single unit without including a guest operating system as done with virtual machines. The most popular container solution is Docker which provides tools for container management like the Docker Host (dockerd) which can create, run, stop, move, or delete a container. Docker has a very popular registry of containers images that can be used by any Docker system; however, in the ONAP context, Docker images are built by the standard CI/CD flow and stored in Nexus repositories. OOM uses the “standard” ONAP docker containers and three new ones specifically created for OOM.
Containers are isolated from each other primarily via name spaces within the Linux kernel without the need for multiple guest operating systems. As such, multiple containers can be deployed with little overhead such as all of ONAP can be deployed on a single host. With some optimization of the ONAP components (e.g. elimination of redundant database instances) it may be possible to deploy ONAP on a single laptop computer.
The following sections describe how the ONAP Helm charts are constructed.