imagedownloads

Documentation

Overview

Package imagedownloads implements image-downloads metadata from simplestreams.

Index

• Constants
• func DefaultSource() simplestreams.DataSource
• func Filter(ftype string) simplestreams.AppendMatchingFunc
• func NewDataSource(baseURL string) simplestreams.DataSource
• func Sort(metadata []*Metadata)
• type Metadata
  • func Fetch(src []simplestreams.DataSource, cons *imagemetadata.ImageConstraint, ...) ([]*Metadata, *simplestreams.ResolveInfo, error)
  • func One(arch, release, stream, ftype string, src func() simplestreams.DataSource) (*Metadata, error)
  • func (m *Metadata) DownloadURL() (*url.URL, error)

Constants

const (
	// DataType is the simplestreams datatype.
	DataType = "image-downloads"
)

Functions

func DefaultSource

func DefaultSource() simplestreams.DataSource

DefaultSource creates a new signed simplestreams datasource for use with the image-downloads datatype.

func Filter

func Filter(ftype string) simplestreams.AppendMatchingFunc

Filter collects only matching products. Series and Arch are filtered by imagemetadata.ImageConstraints. So this really only let's us filter on a file type.

func NewDataSource

func NewDataSource(baseURL string) simplestreams.DataSource

NewDataSource returns a new simplestreams.DataSource from the provided baseURL. baseURL MUST include the image stream.

func Sort

func Sort(metadata []*Metadata)

Sort sorts a slice of ImageMetadata in ascending order of their id in order to ensure the results of Fetch are ordered deterministically.

Types

type Metadata

type Metadata struct {
	Arch string `json:"arch,omitempty"`
	// For testing.
	// TODO(ro) 2016-12-07 BaseURL was jammed on to allow for testing in
	// juju/container/kvm/sync_internal_test. Refactor to pass it in rather
	// than setting it on an otherwise needlessly exported member.
	BaseURL string `json:"-"`
	Release string `json:"release,omitempty"`
	Version string `json:"version,omitempty"`
	FType   string `json:"ftype,omitempty"`
	SHA256  string `json:"sha256,omitempty"`
	Path    string `json:"path,omitempty"`
	Size    int64  `json:"size,omitempty"`
}

Metadata models the information about a particular cloud image download product.

func Fetch

func Fetch(
	src []simplestreams.DataSource,
	cons *imagemetadata.ImageConstraint,
	ff simplestreams.AppendMatchingFunc) ([]*Metadata, *simplestreams.ResolveInfo, error)

Fetch gets product results as Metadata from the provided datasources, given some constraints and an optional filter function.

func One

func One(arch, release, stream, ftype string, src func() simplestreams.DataSource) (*Metadata, error)

One gets Metadata for one content download item: The most recent of:

• architecture
• OS release
• Simplestreams stream
• File image type.

src exists to pass in a data source for testing.

func (*Metadata) DownloadURL

func (m *Metadata) DownloadURL() (*url.URL, error)

DownloadURL returns the URL representing the image.