docs/utils/b2d.go

131 lines
2.6 KiB
Go

package utils
import (
"encoding/json"
"fmt"
"io"
"io/ioutil"
"net"
"net/http"
"net/url"
"os"
"path/filepath"
"time"
)
const (
timeout = time.Second * 5
)
func defaultTimeout(network, addr string) (net.Conn, error) {
return net.DialTimeout(network, addr, timeout)
}
func getClient() *http.Client {
transport := http.Transport{
DisableKeepAlives: true,
Proxy: http.ProxyFromEnvironment,
Dial: defaultTimeout,
}
client := http.Client{
Transport: &transport,
}
return &client
}
type B2dUtils struct {
githubApiBaseUrl string
githubBaseUrl string
}
func NewB2dUtils(githubApiBaseUrl, githubBaseUrl string) *B2dUtils {
defaultBaseApiUrl := "https://api.github.com"
defaultBaseUrl := "https://github.com"
if githubApiBaseUrl == "" {
githubApiBaseUrl = defaultBaseApiUrl
}
if githubBaseUrl == "" {
githubBaseUrl = defaultBaseUrl
}
return &B2dUtils{
githubApiBaseUrl: githubApiBaseUrl,
githubBaseUrl: githubBaseUrl,
}
}
// Get the latest boot2docker release tag name (e.g. "v0.6.0").
// FIXME: find or create some other way to get the "latest release" of boot2docker since the GitHub API has a pretty low rate limit on API requests
func (b *B2dUtils) GetLatestBoot2DockerReleaseURL() (string, error) {
client := getClient()
apiUrl := fmt.Sprintf("%s/repos/boot2docker/boot2docker/releases", b.githubApiBaseUrl)
rsp, err := client.Get(apiUrl)
if err != nil {
return "", err
}
defer rsp.Body.Close()
var t []struct {
TagName string `json:"tag_name"`
}
if err := json.NewDecoder(rsp.Body).Decode(&t); err != nil {
return "", err
}
if len(t) == 0 {
return "", fmt.Errorf("no releases found")
}
tag := t[0].TagName
isoUrl := fmt.Sprintf("%s/boot2docker/boot2docker/releases/download/%s/boot2docker.iso", b.githubBaseUrl, tag)
return isoUrl, nil
}
// Download boot2docker ISO image for the given tag and save it at dest.
func (b *B2dUtils) DownloadISO(dir, file, isoUrl string) error {
u, err := url.Parse(isoUrl)
var src io.ReadCloser
if u.Scheme == "file" {
s, err := os.Open(u.Path)
if err != nil {
return err
}
src = s
} else {
client := getClient()
s, err := client.Get(isoUrl)
if err != nil {
return err
}
src = s.Body
}
defer src.Close()
// Download to a temp file first then rename it to avoid partial download.
f, err := ioutil.TempFile(dir, file+".tmp")
if err != nil {
return err
}
defer os.Remove(f.Name())
if _, err := io.Copy(f, src); err != nil {
// TODO: display download progress?
return err
}
if err := f.Close(); err != nil {
return err
}
if err := os.Rename(f.Name(), filepath.Join(dir, file)); err != nil {
return err
}
return nil
}