pulumi/pkg/backend/filestate/bucket.go
Matt Ellis b14e3d9c35 Do not use os package in filestate backend
Since the filestate backend is now written using the go-cloud blob
abstraction, places where we were using functions from the `os`
package were very unlikely to be correct.

This change removes their uses in favor of APIs provided by
go-cloud (which sometimes requires more work than before).
2019-08-16 13:42:27 -07:00

124 lines
4 KiB
Go

package filestate
import (
"context"
"io"
"path"
"path/filepath"
"github.com/pkg/errors"
"github.com/pulumi/pulumi/pkg/util/logging"
"gocloud.dev/blob"
)
// Bucket is a wrapper around an underlying gocloud blob.Bucket. It ensures that we pass all paths
// to it normalized to forward-slash form like it requires.
type Bucket interface {
Copy(ctx context.Context, dstKey, srcKey string, opts *blob.CopyOptions) (err error)
Delete(ctx context.Context, key string) (err error)
List(opts *blob.ListOptions) *blob.ListIterator
SignedURL(ctx context.Context, key string, opts *blob.SignedURLOptions) (string, error)
ReadAll(ctx context.Context, key string) (_ []byte, err error)
WriteAll(ctx context.Context, key string, p []byte, opts *blob.WriterOptions) (err error)
Exists(ctx context.Context, key string) (bool, error)
}
// wrappedBucket encapsulates a true gocloud blob.Bucket, but ensures that all paths we send to it
// are appropriately normalized to use forward slashes as required by it. Without this, we may use
// filepath.join which can make paths like `c:\temp\etc`. gocloud's fileblob then converts those
// backslashes to the hex string __0x5c__, breaking things on windows completely.
type wrappedBucket struct {
bucket *blob.Bucket
}
func (b *wrappedBucket) Copy(ctx context.Context, dstKey, srcKey string, opts *blob.CopyOptions) (err error) {
return b.bucket.Copy(ctx, filepath.ToSlash(dstKey), filepath.ToSlash(srcKey), opts)
}
func (b *wrappedBucket) Delete(ctx context.Context, key string) (err error) {
return b.bucket.Delete(ctx, filepath.ToSlash(key))
}
func (b *wrappedBucket) List(opts *blob.ListOptions) *blob.ListIterator {
return b.bucket.List(opts)
}
func (b *wrappedBucket) SignedURL(ctx context.Context, key string, opts *blob.SignedURLOptions) (string, error) {
return b.bucket.SignedURL(ctx, filepath.ToSlash(key), opts)
}
func (b *wrappedBucket) ReadAll(ctx context.Context, key string) (_ []byte, err error) {
return b.bucket.ReadAll(ctx, filepath.ToSlash(key))
}
func (b *wrappedBucket) WriteAll(ctx context.Context, key string, p []byte, opts *blob.WriterOptions) (err error) {
return b.bucket.WriteAll(ctx, filepath.ToSlash(key), p, opts)
}
func (b *wrappedBucket) Exists(ctx context.Context, key string) (bool, error) {
return b.bucket.Exists(ctx, filepath.ToSlash(key))
}
// listBucket returns a list of all files in the bucket within a given directory. go-cloud sorts the results by key
func listBucket(bucket Bucket, dir string) ([]*blob.ListObject, error) {
bucketIter := bucket.List(&blob.ListOptions{
Delimiter: "/",
Prefix: dir + "/",
})
files := []*blob.ListObject{}
ctx := context.TODO()
for {
file, err := bucketIter.Next(ctx)
if err == io.EOF {
break
}
if err != nil {
return nil, errors.Wrap(err, "could not list bucket")
}
files = append(files, file)
}
return files, nil
}
// objectName returns the filename of a ListObject (an object from a bucket)
func objectName(obj *blob.ListObject) string {
_, filename := path.Split(obj.Key)
return filename
}
// removeAllByPrefix deletes all objects with a given prefix (i.e. filepath)
func removeAllByPrefix(bucket Bucket, dir string) error {
files, err := listBucket(bucket, dir)
if err != nil {
return errors.Wrap(err, "unable to list bucket objects for removal")
}
for _, file := range files {
err = bucket.Delete(context.TODO(), file.Key)
if err != nil {
logging.V(5).Infof("error deleting object: %v (%v) skipping", file.Key, err)
}
}
return nil
}
// renameObject renames an object in a bucket. the rename requires a download/upload of the object
// due to a go-cloud API limitation
func renameObject(bucket Bucket, source string, dest string) error {
err := bucket.Copy(context.TODO(), dest, source, nil)
if err != nil {
return errors.Wrapf(err, "copying %s to %s", source, dest)
}
err = bucket.Delete(context.TODO(), source)
if err != nil {
logging.V(5).Infof("error deleting source object after rename: %v (%v) skipping", source, err)
}
return nil
}