packer-cn/common/config.go

128 lines
3.3 KiB
Go

package common
import (
"fmt"
"net/url"
"os"
"path/filepath"
"runtime"
"strings"
"time"
)
// PackerKeyEnv is used to specify the key interval (delay) between keystrokes
// sent to the VM, typically in boot commands. This is to prevent host CPU
// utilization from causing key presses to be skipped or repeated incorrectly.
const PackerKeyEnv = "PACKER_KEY_INTERVAL"
// PackerKeyDefault 100ms is appropriate for shared build infrastructure while a
// shorter delay (e.g. 10ms) can be used on a workstation. See PackerKeyEnv.
const PackerKeyDefault = 100 * time.Millisecond
// ScrubConfig is a helper that returns a string representation of
// any struct with the given values stripped out.
func ScrubConfig(target interface{}, values ...string) string {
conf := fmt.Sprintf("Config: %+v", target)
for _, value := range values {
if value == "" {
continue
}
conf = strings.Replace(conf, value, "<Filtered>", -1)
}
return conf
}
// ChooseString returns the first non-empty value.
func ChooseString(vals ...string) string {
for _, el := range vals {
if el != "" {
return el
}
}
return ""
}
// DownloadableURL processes a URL that may also be a file path and returns
// a completely valid URL. For example, the original URL might be "local/file.iso"
// which isn't a valid URL. DownloadableURL will return "file:///local/file.iso"
func DownloadableURL(original string) (string, error) {
if runtime.GOOS == "windows" {
// If the distance to the first ":" is just one character, assume
// we're dealing with a drive letter and thus a file path.
idx := strings.Index(original, ":")
if idx == 1 {
original = "file:///" + original
}
}
url, err := url.Parse(original)
if err != nil {
return "", err
}
if url.Scheme == "" {
url.Scheme = "file"
}
if url.Scheme == "file" {
// Windows file handling is all sorts of tricky...
if runtime.GOOS == "windows" {
// If the path is using Windows-style slashes, URL parses
// it into the host field.
if url.Path == "" && strings.Contains(url.Host, `\`) {
url.Path = url.Host
url.Host = ""
}
// For Windows absolute file paths, remove leading / prior to processing
// since net/url turns "C:/" into "/C:/"
if len(url.Path) > 0 && url.Path[0] == '/' {
url.Path = url.Path[1:len(url.Path)]
}
}
// Only do the filepath transformations if the file appears
// to actually exist.
if _, err := os.Stat(url.Path); err == nil {
url.Path, err = filepath.Abs(url.Path)
if err != nil {
return "", err
}
url.Path, err = filepath.EvalSymlinks(url.Path)
if err != nil {
return "", err
}
url.Path = filepath.Clean(url.Path)
}
if runtime.GOOS == "windows" {
// Also replace all backslashes with forwardslashes since Windows
// users are likely to do this but the URL should actually only
// contain forward slashes.
url.Path = strings.Replace(url.Path, `\`, `/`, -1)
}
}
// Make sure it is lowercased
url.Scheme = strings.ToLower(url.Scheme)
// Verify that the scheme is something we support in our common downloader.
supported := []string{"file", "http", "https"}
found := false
for _, s := range supported {
if url.Scheme == s {
found = true
break
}
}
if !found {
return "", fmt.Errorf("Unsupported URL scheme: %s", url.Scheme)
}
return url.String(), nil
}