Magnum Documentation

Magnum is an OpenStack project which offers container orchestration engines for deploying and man- aging containers as first class resources in OpenStack.

• Free software: under the Apache license
• Source: https://opendev.org/openstack/magnum
• Blueprints: https://blueprints.launchpad.net/magnum
• Bugs: https://bugs.launchpad.net/magnum
• REST Client: https://opendev.org/openstack/python-magnumclient

Chapter One – Architecture

There are several different types of objects in the magnum system:

• Cluster: A collection of node objects where work is scheduled
• ClusterTemplate: An object stores template information about the cluster which is used to create new clusters consistently

Two binaries work together to compose the magnum system. The first binary (accessed by the python- magnumclient code) is the magnum-api REST server. The REST server may run as one process or multiple processes. When a REST request is sent to the client API, the request is sent via AMQP to the magnum-conductor process. The REST server is horizontally scalable. At this time, the conductor is limited to one process, but we intend to add horizontal scalability to the conductor as well.

Chapter Two – Features

• Abstractions for Clusters
• Integration with Kubernetes, Swarm for backend container technology
• Integration with Keystone for multi-tenant security
• Integration with Neutron for Kubernetes multi-tenancy network security
• Integration with Cinder to provide volume service for containers

Chapter Three – Installation Guide

3.1 Magnum Installation Guide

3.1.1 Container Infrastructure Management service overview

The Container Infrastructure Management service consists of the following components:

magnum command-line client A CLI that communicates with the magnum-api to create and manage container clusters. End developers can directly use the magnum REST API.

magnum-api service An OpenStack-native REST API that processes API requests by sending them to the magnum-conductor via AMQP.

magnum-conductor service Runs on a controller machine and connects to heat to orchestrate a cluster. Additionally, it connects to a Docker Swarm or Kubernetes API endpoint.

3.1.2 Install and configure 

This section describes how to install and configure the Container Infrastructure Management service, code-named magnum, on the controller node.

This section assumes that you already have a working OpenStack environment with at least the follow- ing components installed: Identity service, Image service, Compute service, Networking service, Block Storage service and Orchestration service. See OpenStack Install Guides.

To provide access to Docker Swarm or Kubernetes using the native clients (docker or kubectl, respec- tively) magnum uses TLS certificates. To store the certificates, it is recommended to use the Key Manager service, code-named barbican, or you can save them in magnums database.

Optionally, you can install the following components:

• Load Balancer as a Service (LBaaS v2) to create clusters with multiple masters
• Bare Metal service to create baremetal clusters
• Object Storage service to make private Docker registries available to users
• Telemetry Data Collection service to periodically send magnum-related metrics

Note: Installation and configuration vary by distribution.

Important: Magnum creates clusters of compute instances on the Compute service (nova). These instances must have basic Internet connectivity and must be able to reach magnums API server. Make sure that the Compute and Network services are configured accordingly.