caddy/cmd/removebinary_windows.go
Francis Lavoie 749e55c738
caddycmd: Add --keep-backup to upgrade commands (#4387)
* caddycmd: Add `--skip-cleanup` to upgrade commands

This is a partial fix for https://github.com/caddyserver/caddy/issues/4057, making it possible to retain the old build of Caddy, in case something went wrong.

* caddycmd: Fix duplicate error message

The error message "download succeeded, but unable to execute" was repeated, because it was both in the `listModules`/`showVersion` functions and in the calling `upgradeBuild` function. Oversight when this was refactored.

* caddycmd: Implement fix for performing cleanup on Windows

Without this, the cleanup operation would fail with an error message like this:

upgrade: download succeeded, but unable to clean up backup binary: remove C:\caddy\caddy.exe.tmp: Access is denied.

* caddycmd: Rename to `--keep-backup`, simplify build constraints
2021-11-08 11:35:46 -07:00

37 lines
1.4 KiB
Go

// Copyright 2015 Matthew Holt and The Caddy Authors
//
// 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 caddycmd
import (
"os"
"path/filepath"
"syscall"
)
// removeCaddyBinary removes the Caddy binary at the given path.
//
// On Windows, this uses a syscall to indirectly remove the file,
// because otherwise we get an "Access is denied." error when trying
// to delete the binary while Caddy is still running and performing
// the upgrade. "cmd.exe /C" executes a command specified by the
// following arguments, i.e. "del" which will run as a separate process,
// which avoids the "Access is denied." error.
func removeCaddyBinary(path string) error {
var sI syscall.StartupInfo
var pI syscall.ProcessInformation
argv := syscall.StringToUTF16Ptr(filepath.Join(os.Getenv("windir"), "system32", "cmd.exe") + " /C del " + path)
return syscall.CreateProcess(nil, argv, nil, nil, true, 0, nil, nil, &sI, &pI)
}