Action Scripts
Only available with select server licenses.

In addition to transferring files, servedat can be configured to execute scripts and commands in response to client requests.  This allows servedat to perform actions such as post-processing, notifications, and other data management processes on targeted files.

Action Scripts are primarily for use with the movedat client or the ExpeDat Client SDK.  Other clients have limited ability to interact with Action Scripts.

Action Scripts are a variation of Packaging commands and are setup in exactly the same way.  The only difference is in how you use them.  Packaging commands are intended to archive files and stream the archive to the client.  Action Scripts are intended to perform some function and report the result to the client.  But the setup and environment are identical for both.

Syntax

Adding support for an Action Script is done with the Package configuration variable or the "–P" command line option:

Package <suffix>,"<command>" <options> "%s"
  or
servedat -P <suffix>,'"<command>" <options> "%s"'

Note the careful arrangement of single and double quotes on the command line to ensure correct handling by the command-shell.  <suffix> is the action code or file name extension you wish to associate with the given action script.  <command> is the path name of the script or command line utility which will be executed with this action.  <options> includes any command switches needed by the command.

The string "%s" will be replaced with the name of the directory or file targeted by the client.  The command will executed with a current working directory set to the folder containing the file.  Additional variations of the target path are available in the Environment variables.

You may specify multiple action scripts and packaging commands by adding additional "–P" options on the command line or Package variables in the configuration file.

Environment

The command will be executed using the bourne-shell (sh) on unix systems and CreateProcess() on Windows systems.  The current working directory will be set to the parent folder containing the target file.  Environment variables will be inherited from servedat itself.

As of this release, the target pathname must exist and be accessible.  This requirement may be removed in a future release.

If PackTimeout is set, then the command will be terminated by servedat if it runs longer than the specified time.

In addition to the server's environment, the following variables are provided to both Action Scripts and Packaging commands:

Additional environment variables are likely to be introduced in future releases.  Please let us know if you have suggestions.

Example

The following bourne-shell script returns the script environment back to the client.

#!/bin/sh echo Target is $1 printenv

The server can be configured to use this script as follows:

servedat -P "echo,/tmp/echoenv.sh %s" /tmp/

The action can be triggered by movedat like this:

movedat -D user@example.com:somefile=echo

Security

For security reasons, characters which may have special meaning to a command shell are not permitted in the target name.  If one of the following forbidden character appear in the path, either from the client or the home directory path, the action will fail with a pathname error.

" ' ; ` ( ) [ ] & ? * ! ~ | { }

In addition, the backslash character '\' is not permitted on unix systems.

Environment values for SV_ARG and SV_PATHRAW are provided directly by the client and are not validated by servedat in any way.

The script will execute with the same privileges as the user account used for authentication.  The server will advise of additional restrictions using SV_NOOVERWRITE, SV_READONLY, SV_GETONLY, SV_RESTRICTHOME, SV_WRITEONLY, and SV_WRITELISTONLY.  It is up to your action script to interpret and enforce those restrictions.

Because action scripts may execute arbitrary commands, administrators should take care that they are not writeable by untrusted users.