manager

Documentation

Overview

Package manager provides functions to start or stop monitoring of a target.

Index

• Constants
• Variables
• type Config
• type ConnectionManager
• type CredentialsClient
• type Manager
  • func NewManager(cfg Config) (*Manager, error)
  • func (m *Manager) Add(name string, t *tpb.Target, sr *gpb.SubscribeRequest) error
  • func (m *Manager) Reconnect(name string) error
  • func (m *Manager) Remove(name string) error

Constants

const (
	// Address is deprecated, proxies should support multiple addresses via the
	// Addresses metadata key.
	Address   = "address"
	Addresses = "addresses"
	Password  = "password"
	Target    = "target"
	Username  = "username"
)

gRPC metadata keys.

const AddrSeparator = ";"

AddrSeparator delimits the chain of addresses used to connect to a target.

Variables

var (
	// ErrPending indicates a pending subscription attempt for the target exists.
	ErrPending = errors.New("subscription already pending")

	// RetryBaseDelay is the initial retry interval for target connections.
	RetryBaseDelay = time.Second
	// RetryMaxDelay caps the retry interval for target connections.
	RetryMaxDelay = time.Minute
	// RetryRandomization is the randomization factor applied to the retry
	// interval.
	RetryRandomization = 0.5
)

Types

type Config

type Config struct {
	// Connect will be invoked when a target connects.
	Connect func(string)
	// Credentials is an optional client used to lookup passwords for targets
	// with a specified username and password ID.
	Credentials CredentialsClient
	// Reset will be invoked when a target disconnects.
	Reset func(string)
	// Sync will be invoked in response to gNMI sync updates.
	Sync func(string)
	// Timeout defines the optional duration to wait for a gRPC dial.
	Timeout time.Duration
	// Update will be invoked in response to gNMI updates.
	Update func(*gpb.Notification)
	// ConnectionManager is used to create gRPC connections.
	ConnectionManager ConnectionManager
	// ConnectError record error from subcribe connections.
	ConnectError func(string, error)
}

Config is used by Manager to handle updates.

type ConnectionManager

type ConnectionManager interface {
	Connection(ctx context.Context, addr string) (conn *grpc.ClientConn, done func(), err error)
}

ConnectionManager defines a function to create a *grpc.ClientConn along with a done function that will be called when the returned connection handle is unused.

type CredentialsClient

type CredentialsClient interface {
	Lookup(ctx context.Context, key string) (string, error)
}

CredentialsClient is an interface for credentials lookup.

type Manager

type Manager struct {
	// contains filtered or unexported fields
}

Manager provides functionality for making gNMI subscriptions to targets and handling updates.

func NewManager

func NewManager(cfg Config) (*Manager, error)

NewManager returns a new target Manager.

func (*Manager) Add

func (m *Manager) Add(name string, t *tpb.Target, sr *gpb.SubscribeRequest) error

Add adds the target to Manager and starts a streaming subscription that continues until Remove is called. Failed subscriptions are retried using exponential backoff.

After Add returns successfully, re-adding a target returns an error, unless first removed.

func (*Manager) Reconnect

func (m *Manager) Reconnect(name string) error

Reconnect triggers a reconnection for the specified target.

func (*Manager) Remove

func (m *Manager) Remove(name string) error

Remove stops the streaming connection to the target. Removing a target not added returns an error. Remove does not return until the subscription is completed and no further updates will occur.