servicelabel

README

Service Label

The servicelabel is a small Core Agent Plugin, which other plugins can use to obtain the microservice label, i.e. the string used to identify the particular VNF. The label is primarily used to prefix keys in etcd datastore so that the configurations of different VNFs do not get mixed up.

API

described in doc.go

Configuration

• the serviceLabel can be set either by commandline flag microservice-label or environment variable MICROSERVICE_LABEL

Dependencies

-

Example

Example of retrieving and using the microservice label:

plugin.Label = servicelabel.GetAgentLabel()
dbw.Watch(dataChan, cfg.SomeConfigKeyPrefix(plugin.Label))

Documentation

Overview

Package servicelabel provides support for creating/retrieving an identifier (a service label) for a CN-Infra based app.

p := serviceLabel.Plugin{}
// initialization plugin handled by agent core

To retrieve service label of the VNF instance, run:

label = p.GetAgentLabel()

To retrieve prefix that can be used to access configuration of the VNF instance in key-value datastore, run:

prefix = p.GetAgentPrefix()

To retrieve prefix for a different VNF instance, run:

otherPrefix = p.GetDifferentAgentPrefix(differentLabel)

To retrieve prefix that identifies configuration of all instances:

allInstances = p.GetAllAgentsPrefix()

Index

• Constants
• func GetAllAgentsPrefix() string
• func GetDifferentAgentPrefix(microserviceLabel string) string
• type Plugin
  • func OfDifferentAgent(microserviceLabel string) *Plugin
  • func (p *Plugin) Close() error
  • func (p *Plugin) GetAgentLabel() string
  • func (p *Plugin) GetAgentPrefix() string
  • func (p *Plugin) GetAllAgentsPrefix() string
  • func (p *Plugin) GetDifferentAgentPrefix(microserviceLabel string) string
  • func (p *Plugin) Init() error
• type ReaderAPI

Constants

const MicroserviceLabelEnvVar = "MICROSERVICE_LABEL"

MicroserviceLabelEnvVar label this is inferred from the flag name

Functions

func GetAllAgentsPrefix

func GetAllAgentsPrefix() string

GetAllAgentsPrefix returns the string that is supposed to be used as the prefix for configuration subtree of the particular VPP Agent instance (e.g. in ETCD).

func GetDifferentAgentPrefix

func GetDifferentAgentPrefix(microserviceLabel string) string

GetDifferentAgentPrefix returns the string that is supposed to be used as the prefix for configuration "subtree" of the particular VPP Agent instance (e.g. in ETCD).

Types

type Plugin

type Plugin struct {
	// MicroserviceLabel identifies particular VNF.
	// Used primarily as a key prefix to ETCD data store.
	MicroserviceLabel string
}

Plugin exposes the service label(i.e. the string used to identify the particular VNF) to the other plugins.

func OfDifferentAgent

func OfDifferentAgent(microserviceLabel string) *Plugin

OfDifferentAgent sets micorserivce label and returns new instance of Plugin. It is meant for watching DB by prefix of different agent. You can pass/inject instance of this plugin for example to kvdbsync.

func (*Plugin) Close

func (p *Plugin) Close() error

Close is called at plugin cleanup phase.

func (*Plugin) GetAgentLabel

func (p *Plugin) GetAgentLabel() string

GetAgentLabel returns string that is supposed to be used to distinguish (ETCD) key prefixes for particular VNF (particular VPP Agent configuration)

func (*Plugin) GetAgentPrefix

func (p *Plugin) GetAgentPrefix() string

GetAgentPrefix returns the string that is supposed to be used as the prefix for configuration of current MicroserviceLabel "subtree" of the particular VPP Agent instance (e.g. in ETCD).

func (*Plugin) GetAllAgentsPrefix

func (p *Plugin) GetAllAgentsPrefix() string

GetAllAgentsPrefix returns the string that is supposed to be used as the prefix for configuration subtree of the particular VPP Agent instance (e.g. in ETCD).

func (*Plugin) GetDifferentAgentPrefix

func (p *Plugin) GetDifferentAgentPrefix(microserviceLabel string) string

GetDifferentAgentPrefix returns the string that is supposed to be used as the prefix for configuration "subtree" of the particular VPP Agent instance (e.g. in ETCD).

func (*Plugin) Init

func (p *Plugin) Init() error

Init is called at plugin initialization.

type ReaderAPI

type ReaderAPI interface {
	// GetAgentLabel returns string that is supposed to be used to distinguish
	// (ETCD) key prefixes for particular VNF (particular VPP Agent configuration)
	GetAgentLabel() string

	// GetAgentPrefix returns the string that is supposed to be used as the prefix for configuration of current
	// MicroserviceLabel "subtree" of the particular VPP Agent instance (e.g. in ETCD).
	GetAgentPrefix() string
	// GetDifferentAgentPrefix returns the string that is supposed to be used as the prefix for configuration
	// "subtree" of the particular VPP Agent instance (e.g. in ETCD).
	GetDifferentAgentPrefix(microserviceLabel string) string

	// GetAllAgentsPrefix returns the string that is supposed to be used as the prefix for configuration
	// subtree of the particular VPP Agent instance (e.g. in ETCD).
	GetAllAgentsPrefix() string
}

ReaderAPI allows to read agent micorservice label with prefix. Reason for doing this is to have prefix for all keys of the agent.