selfupdate

Documentation

Overview

Update protocol:

GET hk.heroku.com/hk/linux-amd64.json

200 ok
{
    "Version": "2",
    "Sha256": "..." // base64
}

then

GET hkpatch.s3.amazonaws.com/hk/1/2/linux-amd64

200 ok
[bsdiff data]

or

GET hkdist.s3.amazonaws.com/hk/2/linux-amd64.gz

200 ok
[gzipped executable data]

Index

• Variables
• type HTTPRequester
  • func (httpRequester *HTTPRequester) Fetch(url string) (io.ReadCloser, error)
• type Requester
• type Updater
  • func (u *Updater) BackgroundRun(update bool) error
  • func (u *Updater) WantUpdate() bool

Variables

var ErrHashMismatch = errors.New("new file hash mismatch after patch")

Types

type HTTPRequester

type HTTPRequester struct {
}

HTTPRequester is the normal requester that is used and does an HTTP to the url location requested to retrieve the specified data.

func (*HTTPRequester) Fetch

func (httpRequester *HTTPRequester) Fetch(url string) (io.ReadCloser, error)

Fetch will return an HTTP request to the specified url and return the body of the result. An error will occur for a non 200 status code.

type Requester

type Requester interface {
	Fetch(url string) (io.ReadCloser, error)
}

Requester interface allows developers to customize the method in which requests are made to retrieve the version and binary

type Updater

type Updater struct {
	CurrentVersion string    // Currently running version.
	ApiURL         string    // Base URL for API requests (json files).
	CmdName        string    // Command name is appended to the ApiURL like http://apiurl/CmdName/. This represents one binary.
	BinURL         string    // Base URL for full binary downloads.
	DiffURL        string    // Base URL for diff downloads.
	Dir            string    // Directory to store selfupdate state.
	ForceCheck     bool      // Check for update regardless of cktime timestamp
	Requester      Requester //Optional parameter to override existing http request handler
	Info           struct {
		Version string
		Sha256  []byte
	}
}

Updater is the configuration and runtime data for doing an update.

Note that ApiURL, BinURL and DiffURL should have the same value if all files are available at the same location.

Example:

updater := &selfupdate.Updater{
	CurrentVersion: version,
	ApiURL:         "http://updates.yourdomain.com/",
	BinURL:         "http://updates.yourdownmain.com/",
	DiffURL:        "http://updates.yourdomain.com/",
	Dir:            "update/",
	CmdName:        "myapp", // app name
}
if updater != nil {
	go updater.BackgroundRun()
}

func (*Updater) BackgroundRun

func (u *Updater) BackgroundRun(update bool) error

BackgroundRun starts the update check and apply cycle.

func (*Updater) WantUpdate

func (u *Updater) WantUpdate() bool