Open Stack

• Keystone: Identity service
• Nova: Compute
• Glance: Image service
• Neutron: Networking
• Horizon: Dashboard
• Cinder: Block storage
• Heat: Orchestration
• Telemetry: Celiometer
• Swift: Object storage
• Rally: Benchmark service
• Ironic: Bare metal
• Designate: DNS service
• Manila: Shared file systems

Nova

Nova provides virtual servers on demand.

• Scheduler: manages virtual server instances on hosts
• Network: manages IP forwarding, bridges, vlans
• Compute: manages communication with hypervisors and virtual servers
• Conductor: manages requests that need coordination, acts as db proxy

Neutron

Standalone service that deploys processes across nodes.

• Neutron-server: services the networking API, enforces network-model and IP addressing of each port
• Plugin agent: runs on each compute node and manages local virtual switch configs
• DHCP agent: provides DHCP services to tenant networks
• L3 agent: provides L3/NAT forwarding to external network access of VMs
• SDN services: provides additional networking services to tenant networks

An OpenStack setup usually needs for distinct networks:

• Management network
• Guest network
• External network
• API network

Glance

Virtual machine image registration and storage with pluggable storage backends.

Cinder

Block level storage for VMs with puggable backends.

Swift

Object storage to store and retrieve data. Objects are stored in buckets. Eventually consistent design.

Keystone

Identity provider for authentication and authorization used by all OpenStack services. Pluggable front- and backends. Supports federated identity management.

Horizon

Modular web based user interface / dashboard to manage OpenStack core functionality. Specialised services require the use of the command line.

Ceilometer

Optional service for telemetry data. Complete monitoring environment for services, resources and infrastructure. Also provides metrics for billing and scaling decisions.

Heat

Optional service for orchestration. Orchestrates using Heat Orchestration Template (HOT).

Main components:

• Heat-cfn (cloudformation)
• Heat-api
• Heat-engine
• Heat-metadata