tunnel

type Cloudflare struct {
	// Binary is an explicit cloudflared executable; when set, nothing else
	// is tried.
	Binary string
	// Timeout bounds how long Open waits for the URL and then for its
	// hostname to be published in DNS; defaults to 30s.
	Timeout time.Duration
	// InstallDir is where a downloaded cloudflared is kept (sam-one uses
	// <data-dir>/bin). Empty disables both the cache and downloads.
	InstallDir string
	// Consent is asked before downloading; installing cloudflared means
	// accepting Cloudflare's license, so this must be an explicit choice.
	// Nil never downloads.
	Consent func(version, url string) bool
	// ReleaseURL overrides the GitHub release download prefix (mirrors,
	// tests). The pinned digests still apply.
	ReleaseURL string
	// HTTPClient performs the download; nil uses a 10 minute timeout.
	HTTPClient *http.Client
	// LookupHost asks whether the assigned hostname exists yet; nil asks
	// the zone's authoritative nameserver (see authoritativeLookup). Tests
	// stub it.
	LookupHost func(ctx context.Context, host string) ([]string, error)
}

type Provider interface {
	// Name is the operator-facing identifier (e.g. "cloudflare").
	Name() string
	// Open publishes target, a local http://host:port URL, and returns once
	// the public URL is known or ctx expires.
	Open(ctx context.Context, target string) (Tunnel, error)
}

type Tunnel interface {
	// URL is the public https base URL that reaches the local target.
	URL() string
	// Done is closed once the tunnel has stopped forwarding, for whatever
	// reason; Err then reports why (nil after Close).
	Done() <-chan struct{}
	Err() error
	// Close tears the tunnel down.
	Close() error
}