terraform/configs/configload/getter.go

153 lines
4.8 KiB
Go

package configload
import (
"fmt"
"log"
"os"
"path/filepath"
cleanhttp "github.com/hashicorp/go-cleanhttp"
getter "github.com/hashicorp/go-getter"
)
// We configure our own go-getter detector and getter sets here, because
// the set of sources we support is part of Terraform's documentation and
// so we don't want any new sources introduced in go-getter to sneak in here
// and work even though they aren't documented. This also insulates us from
// any meddling that might be done by other go-getter callers linked into our
// executable.
var goGetterDetectors = []getter.Detector{
new(getter.GitHubDetector),
new(getter.BitBucketDetector),
new(getter.GCSDetector),
new(getter.S3Detector),
new(getter.FileDetector),
}
var goGetterNoDetectors = []getter.Detector{}
var goGetterDecompressors = map[string]getter.Decompressor{
"bz2": new(getter.Bzip2Decompressor),
"gz": new(getter.GzipDecompressor),
"xz": new(getter.XzDecompressor),
"zip": new(getter.ZipDecompressor),
"tar.bz2": new(getter.TarBzip2Decompressor),
"tar.tbz2": new(getter.TarBzip2Decompressor),
"tar.gz": new(getter.TarGzipDecompressor),
"tgz": new(getter.TarGzipDecompressor),
"tar.xz": new(getter.TarXzDecompressor),
"txz": new(getter.TarXzDecompressor),
}
var goGetterGetters = map[string]getter.Getter{
"file": new(getter.FileGetter),
"gcs": new(getter.GCSGetter),
"git": new(getter.GitGetter),
"hg": new(getter.HgGetter),
"s3": new(getter.S3Getter),
"http": getterHTTPGetter,
"https": getterHTTPGetter,
}
var getterHTTPClient = cleanhttp.DefaultClient()
var getterHTTPGetter = &getter.HttpGetter{
Client: getterHTTPClient,
Netrc: true,
}
// A reusingGetter is a helper for the module installer that remembers
// the final resolved addresses of all of the sources it has already been
// asked to install, and will copy from a prior installation directory if
// it has the same resolved source address.
//
// The keys in a reusingGetter are resolved and trimmed source addresses
// (with a scheme always present, and without any "subdir" component),
// and the values are the paths where each source was previously installed.
type reusingGetter map[string]string
// getWithGoGetter retrieves the package referenced in the given address
// into the installation path and then returns the full path to any subdir
// indicated in the address.
//
// The errors returned by this function are those surfaced by the underlying
// go-getter library, which have very inconsistent quality as
// end-user-actionable error messages. At this time we do not have any
// reasonable way to improve these error messages at this layer because
// the underlying errors are not separatelyr recognizable.
func (g reusingGetter) getWithGoGetter(instPath, addr string) (string, error) {
packageAddr, subDir := splitAddrSubdir(addr)
log.Printf("[DEBUG] will download %q to %s", packageAddr, instPath)
realAddr, err := getter.Detect(packageAddr, instPath, getter.Detectors)
if err != nil {
return "", err
}
var realSubDir string
realAddr, realSubDir = splitAddrSubdir(realAddr)
if realSubDir != "" {
subDir = filepath.Join(realSubDir, subDir)
}
if realAddr != packageAddr {
log.Printf("[TRACE] go-getter detectors rewrote %q to %q", packageAddr, realAddr)
}
if prevDir, exists := g[realAddr]; exists {
log.Printf("[TRACE] copying previous install %s to %s", prevDir, instPath)
err := os.Mkdir(instPath, os.ModePerm)
if err != nil {
return "", fmt.Errorf("failed to create directory %s: %s", instPath, err)
}
err = copyDir(instPath, prevDir)
if err != nil {
return "", fmt.Errorf("failed to copy from %s to %s: %s", prevDir, instPath, err)
}
} else {
log.Printf("[TRACE] fetching %q to %q", realAddr, instPath)
client := getter.Client{
Src: realAddr,
Dst: instPath,
Pwd: instPath,
Mode: getter.ClientModeDir,
Detectors: goGetterNoDetectors, // we already did detection above
Decompressors: goGetterDecompressors,
Getters: goGetterGetters,
}
err = client.Get()
if err != nil {
return "", err
}
// Remember where we installed this so we might reuse this directory
// on subsequent calls to avoid re-downloading.
g[realAddr] = instPath
}
// Our subDir string can contain wildcards until this point, so that
// e.g. a subDir of * can expand to one top-level directory in a .tar.gz
// archive. Now that we've expanded the archive successfully we must
// resolve that into a concrete path.
var finalDir string
if subDir != "" {
finalDir, err = getter.SubdirGlob(instPath, subDir)
log.Printf("[TRACE] expanded %q to %q", subDir, finalDir)
if err != nil {
return "", err
}
} else {
finalDir = instPath
}
// If we got this far then we have apparently succeeded in downloading
// the requested object!
return filepath.Clean(finalDir), nil
}