mongodbrelation

Documentation

Overview

The mongodbrelation package implements a Juju mongodb relation.

Importing this package also registers the type *mgo.Session with the httpservice package, so that it can be used as a relation field with httpservice.Service.Register.

For example, to register a web service that requires a MongoDB connection, you might do something like this:

type relations struct {
	Session *mgo.Session	`httpservice:"mongodb"`
}
func RegisterHooks(r *hook.Registry) {
	var svc httpservice.Service
	svc.Register(r, "somename", "http", func(_ struct{}, rel *relations) (httpservice.Handler, error) {
		// rel.Session contains the actual MongoDB connection.
		return newHandler(rel)
	})
}

This would create a Juju requirer relation named "mongodb" and dial the related MongoDB instance before creating the HTTP handler.

Index

• type Requirer
  • func (req *Requirer) Addresses() []string
  • func (req *Requirer) Register(r *hook.Registry, relationName string)
  • func (req *Requirer) URL() string

Types

type Requirer

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

Requirer represents the requirer side of an mongodb relation.

func (*Requirer) Addresses

func (req *Requirer) Addresses() []string

Addresses returns the addresses of the current mongodb servers.

func (*Requirer) Register

func (req *Requirer) Register(r *hook.Registry, relationName string)

Register registers an mongodb requirer relation with the given relation name with the given hook registry.

To find out when the host addresses change, register a wildcard ("*") hook.

func (*Requirer) URL

func (req *Requirer) URL() string

URL returns a URL suitable for passing to mgo.Dial. If there are no current addresses, it returns the empty string. TODO does this work with IPv6?