# Automatic Updates / Frozen Deployments

Added in version 0.10.3.d.

Salt has support for the Esky application freezing and update tool. This tool allows one to build a complete zipfile out of the salt scripts and all their dependencies - including shared objects / DLLs.

## Getting Started

To build frozen applications, suitable build environment will be needed for each platform. You should probably set up a virtualenv in order to limit the scope of Q/A.

This process does work on Windows. Directions are available at https://github.com/saltstack/salt-windows-install for details on installing Salt in Windows. Only the 32-bit Python and dependencies have been tested, but they have been tested on 64-bit Windows.

Install `bbfreeze`, and then `esky` from PyPI in order to enable the `bdist_esky` command in `setup.py`. Salt itself must also be installed, in addition to its dependencies.

## Building and Freezing

Once you have your tools installed and the environment configured, use `setup.py` to prepare the distribution files.

    python setup.py sdist
    python setup.py bdist

Once the distribution files are in place, Esky can be used traverse the module tree and pack all the scripts up into a redistributable.

    python setup.py bdist_esky

There will be an appropriately versioned `salt-VERSION.zip` in `dist/` if everything went smoothly.

### Windows

`C:\Python27\lib\site-packages\zmq` will need to be added to the PATH variable. This helps bbfreeze find the zmq DLL so it can pack it up.

## Using the Frozen Build

Unpack the zip file in the desired install location. Scripts like `salt-minion` and `salt-call` will be in the root of the zip file. The associated libraries and bootstrapping will be in the directories at the same level. (Check the Esky documentation for more information)

To support updating your minions in the wild, put the builds on a web server that the minions can reach. `salt.modules.saltutil.update()` will trigger an update and (optionally) a restart of the minion service under the new version.

## Troubleshooting

### A Windows minion isn't responding

The process dispatch on Windows is slower than it is on *nix. It may be necessary to add '-t 15' to salt commands to give minions plenty of time to return.

### Windows and the Visual Studio Redist

The Visual C++ 2008 32-bit redistributable will need to be installed on all Windows minions. Esky has an option to pack the library into the zipfile, but OpenSSL does not seem to acknowledge the new location. If a `no OPENSSL_Applink` error appears on the console when trying to start a frozen minion, the redistributable is not installed.

### Mixed Linux environments and Yum

The Yum Python module doesn't appear to be available on any of the standard Python package mirrors. If RHEL/CentOS systems need to be supported, the frozen build should created on that platform to support all the Linux nodes. Remember to build the virtualenv with `--system-site-packages` so that the `yum` module is included.

### Automatic (Python) module discovery

Automatic (Python) module discovery does not work with the late-loaded scheme that Salt uses for (Salt) modules. Any misbehaving modules will need to be explicitly added to the `freezer_includes` in Salt's `setup.py`. Always check the zipped application to make sure that the necessary modules were included.