update

type Checker struct {
	Source   Source
	Settings func(ctx context.Context) (Settings, error)
	// Current is this binary's version, "dev" for a development build.
	Current  string
	Install  Install
	Clock    clock.Clock
	Logger   *zap.Logger
	Interval time.Duration
	// contains filtered or unexported fields
}

type GitHub struct {
	HTTP    *http.Client
	URL     string
	Version string
}

type ImageVerifier struct {
	// Repository is the image, without a tag: index.docker.io/trypando/pando.
	Repository string
	Trusted    func(ctx context.Context) (root.TrustedMaterial, error)
	Remote     []remote.Option
}

type Install struct {
	Kind string `json:"kind"`
}

type Release struct {
	Version     string    `json:"version"`
	Prerelease  bool      `json:"prerelease"`
	PublishedAt time.Time `json:"published_at"`
	URL         string    `json:"url"`
	// Notes is the version's CHANGELOG.md section, as Markdown.
	Notes string `json:"notes"`
	// Security is set when the Security section names an advisory rather than
	// saying "No new advisories." (docs/releasing.md).
	Security bool `json:"security"`
	// Breaking is set when the version may break what the one before it did:
	// a MAJOR bump, or a MINOR one before 1.0 (docs/releasing.md).
	Breaking bool `json:"breaking"`
}

type Settings struct {
	Enabled bool
	Channel policy.UpdateChannel
}

type Source interface {
	Releases(ctx context.Context) ([]Release, error)
}

type Status struct {
	Current string `json:"current"`
	// Development is set for a binary no release built, which has no version
	// to compare: it is told what the latest is, never that it is behind.
	Development bool                 `json:"development"`
	Enabled     bool                 `json:"enabled"`
	Channel     policy.UpdateChannel `json:"channel"`
	CheckedAt   *time.Time           `json:"checked_at,omitempty"`
	// Error is why the last check failed, when it did. What an earlier check
	// found is still reported beside it.
	Error  string `json:"error,omitempty"`
	Latest string `json:"latest,omitempty"`
	// Available is set when Latest is newer than Current.
	Available bool `json:"available"`
	// Releases are the versions after Current up to Latest, newest first.
	Releases []Release `json:"releases"`
	Security bool      `json:"security"`
	Breaking bool      `json:"breaking"`
	// Upgrade says how to move this installation to Latest (R-352).
	Upgrade *Upgrade `json:"upgrade,omitempty"`
}

type Upgrade struct {
	Version string `json:"version"`
	// Image is the image to run, for a container install.
	Image string `json:"image,omitempty"`
	// Command upgrades an installation run from the release's Compose file,
	// from the directory that file is in.
	Command string `json:"command"`
	// Instructions says the same in a sentence, including the case the
	// command does not cover.
	Instructions string `json:"instructions"`
}