Adrien Delorme 9f82b75e57 Use the hashicorp/go-getter to download files
* removed packer.Cache and references since packer.Cache is never used except in the download step. The download step now uses the new func packer.CachePath(targetPath) for this, the behavior is the same.
* removed download code from packer that was reimplemented into the go-getter library: progress bar, http download restart, checksuming from file, skip already downloaded files, symlinking, make a download cancellable by context.
* on windows if packer is running without symlinking rights and we are getting a local file, the file will be copied instead to avoid errors.
* added unit tests for step_download that are now CI tested on windows, mac & linux.
* files are now downloaded under cache dir `sha1(filename + "?checksum=" + checksum) + file_extension`
* since the output dir is based on the source url and the checksum, when the checksum fails, the file is auto deleted.
* a download file is protected and locked by a file lock,
* updated docs
* updated go modules and vendors
2019-03-13 12:11:58 +01:00

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Go

// Copyright 2016 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package internal
import (
"context"
"time"
gax "github.com/googleapis/gax-go/v2"
)
// Retry calls the supplied function f repeatedly according to the provided
// backoff parameters. It returns when one of the following occurs:
// When f's first return value is true, Retry immediately returns with f's second
// return value.
// When the provided context is done, Retry returns with an error that
// includes both ctx.Error() and the last error returned by f.
func Retry(ctx context.Context, bo gax.Backoff, f func() (stop bool, err error)) error {
return retry(ctx, bo, f, gax.Sleep)
}
func retry(ctx context.Context, bo gax.Backoff, f func() (stop bool, err error),
sleep func(context.Context, time.Duration) error) error {
var lastErr error
for {
stop, err := f()
if stop {
return err
}
// Remember the last "real" error from f.
if err != nil && err != context.Canceled && err != context.DeadlineExceeded {
lastErr = err
}
p := bo.Pause()
if cerr := sleep(ctx, p); cerr != nil {
if lastErr != nil {
return Annotatef(lastErr, "retry failed with %v; last error", cerr)
}
return cerr
}
}
}