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The file Packer provisioner uploads files to machines built by Packer. The recommended usage of the file provisioner is to use it to upload files, and then use shell provisioner to move them to the proper place, set permissions, etc. docs File - Provisioners docs-provisioners-file

File Provisioner

Type: file

The file Packer provisioner uploads files to machines built by Packer. The recommended usage of the file provisioner is to use it to upload files, and then use shell provisioner to move them to the proper place, set permissions, etc.

The file provisioner can upload both single files and complete directories.

Basic Example

{
  "type": "file",
  "source": "app.tar.gz",
  "destination": "/tmp/app.tar.gz"
}

Configuration Reference

The available configuration options are listed below. All elements are required.

  • source (string) - The path to a local file or directory to upload to the machine. The path can be absolute or relative. If it is relative, it is relative to the working directory when Packer is executed. If this is a directory, the existence of a trailing slash is important. Read below on uploading directories.

  • destination (string) - The path where the file will be uploaded to in the machine. This value must be a writable location and any parent directories must already exist.

  • direction (string) - The direction of the file transfer. This defaults to "upload". If it is set to "download" then the file "source" in the machine will be downloaded locally to "destination"

Directory Uploads

The file provisioner is also able to upload a complete directory to the remote machine. When uploading a directory, there are a few important things you should know.

First, the destination directory must already exist. If you need to create it, use a shell provisioner just prior to the file provisioner in order to create the directory. If the destination directory does not exist, the file provisioner may succeed, but it will have undefined results.

Next, the existence of a trailing slash on the source path will determine whether the directory name will be embedded within the destination, or whether the destination will be created. An example explains this best:

If the source is /foo (no trailing slash), and the destination is /tmp, then the contents of /foo on the local machine will be uploaded to /tmp/foo on the remote machine. The foo directory on the remote machine will be created by Packer.

If the source, however, is /foo/ (a trailing slash is present), and the destination is /tmp, then the contents of /foo will be uploaded into /tmp directly.

This behavior was adopted from the standard behavior of rsync. Note that under the covers, rsync may or may not be used.

Uploading files that don't exist before Packer starts

In general, local files used as the source must exist before Packer is run. This is great for catching typos and ensuring that once a build is started, that it will succeed. However, this also means that you can't generate a file during your build and then upload it using the file provisioner later. A convenient workaround is to upload a directory instead of a file. The directory still must exist, but its contents don't. You can write your generated file to the directory during the Packer run, and have it be uploaded later.

The behavior when uploading symbolic links depends on the communicator. The Docker communicator will preserve symlinks, but all other communicators will treat local symlinks as regular files. If you wish to preserve symlinks when uploading, it's recommended that you use tar. Below is an example of what that might look like:

$ ls -l files
total 16
drwxr-xr-x  3 mwhooker  staff  102 Jan 27 17:10 a
lrwxr-xr-x  1 mwhooker  staff    1 Jan 27 17:10 b -> a
-rw-r--r--  1 mwhooker  staff    0 Jan 27 17:10 file1
lrwxr-xr-x  1 mwhooker  staff    5 Jan 27 17:10 file1link -> file1
$ ls -l toupload
total 0
-rw-r--r--  1 mwhooker  staff    0 Jan 27 17:10 files.tar
{
  "provisioners": [
    {
      "type": "shell-local",
      "command": "tar cf toupload/files.tar files"
    },
    {
      "destination": "/tmp/",
      "source": "./toupload",
      "type": "file"
    },
    {
      "inline": [
        "cd /tmp && tar xf toupload/files.tar",
        "rm toupload/files.tar"
      ],
      "type": "shell"
    }
  ]
}

Slowness when transferring large files over WinRM.

Because of the way our WinRM transfers works, it can take a very long time to upload and download even moderately sized files. If you're experiencing slowness using the file provisioner on Windows, it's suggested that you set up an SSH server and use the ssh communicator. If you only want to transfer files to your guest, and if your builder supports it, you may also use the http_directory directive. This will cause that directory to be available to the guest over http, and set the environment variable PACKER_HTTP_ADDR to the address.