OpenStack NFV Orchestration服务，暨OpenStack Tacker入门指南

OpenStack NFV Orchestration服务(OpenStack Tacker)用以构建GVNFM和NFVO，从而能够支持在NFVI平台上（如OpenStack）部署和操作网络服务（NS）和虚拟网络功能（VNF）。
OpenStack NFV Orchestration服务遵循ETSI-GS MANO Architecture Framework标准，提供一个功能栈，以将VNF装配成端对端的网络服务。
OpenStack NFV Orchestration服务的当前版本v1.0，Python实现，最早随OpenStack Liberty版本发布。
1. OpenStack NFV Orchestration的组成部分
1)NFV Catalog

• NS Descriptors，描述多个网络服务的动态组合
• VNF Descriptors，描述单个VNF
• VNF Forwarding Graph Descriptors (VNFFGD)，描述VNF之间的流量关系

2)VNFM

• life-cycle of VNF
• Facilitate initial configuration
• placement of high-performance NFV workloads
• Health monitoring
• Auto Healing / Auto Scaling VNFs

3)NFVO

• Templatized end-to-end Network Service deployment
• VNF placement policy
• VNFs connected
• VIM Resource Checks and Resource Allocation
• Orchestrate VNFs across Multiple VIMs and Multiple Sites

2. OpenStack NFV Orchestration服务的基本工作流程
1)利用镜像文件实例化一个VM（即VDU, Virtual Deployment Unit）
2)在VDU中创建或获取YAML模板文件
3)Onboarding VNF，即基于YAML模板文件创建VNFD，并得到VNFD ID

tacker vnfd-create --vnfd-file sample-vnfd.yaml 

4)Deploying VNF
5)通过VNFD创建VNF

tacker vnf-create --vnfd-id  
或
tacker vnf-create --vnfd-name  

6)直接通过YAML模板文件创建VNF

tacker vnf-create --vnfd-template sample-vnfd-hello-world.yaml 

7)操作VNF实例

tacker vim-list
tacker vnfd-list
tacker vnf-list
tacker vnf-show 
tacker vnfd-show 

8)删除VNF和VNFD

tacker vnf-delete 
tacker vnfd-delete 

3. OpenStack NFV Orchestration服务的APIs

• /
• /v1.0/extensions
• 
  
• /v1.0/vnfds
• /v1.0/vnfs
• 
  
• /v1.0/vims, controlling and managing Network Function Virtualization Infrastructure (NFVI) 
• 
  
• /v1.0/events
• 
  
• /v1.0/vnffgds
• /v1.0/vnffgs
• 
  
• /v1.0/nfps, Network Forwarding Paths (NFPs), a component of VNFFG and contains a Service Function Chain (SFC) and a classifier
• /v1.0/classifiers, a component of a NFP and defines policies to distinguish which traffic should enter the related SFC
• /v1.0/sfcs, Service Function Chains (SFCs)
• 
  
• /v1.0/nsds, Network Service Descriptors, a TOSCA template that describes the deployment and behaviour of a Network Service (NS) using a collection of VNFs
• /v1.0/nss, Network Servicess (NSs), NS resources are instantiations of network services described in the associated NSD TOSCA template.

4. VNFC扩展:

OpenStack NFV Orchestration服务不满足于通过镜像文件预定义的网络功能，还可以通过VNFC实现灵活配置的网络功能。
VNF Component (VNFC)是一种定义网络功能的软件，部署在VDU中。

5. 参考文献

https://wiki.openstack.org/wiki/Tacker
http://specs.openstack.org/openstack/tacker-specs/
https://docs.openstack.org/developer/tacker/
https://github.com/openstack/tacker
https://developer.openstack.org/api-ref/nfv-orchestration/v1/