.. _ssh-ext-alternatives:

==================== SSH Ext Alternatives

In the 2019.2.0 release the ssh_ext_alternatives feature was added. This allows salt-ssh to work across different supported python versions. You will need to ensure you have the following:

• Salt is installed, with all required dependencies for the Python version.
• Everything needs to be importable from the respective Python environment.

To enable using this feature you will need to edit the master configuration similar to below:

.. code-block:: yaml

   ssh_ext_alternatives:
       2019.2:                     # Namespace, can be anything.
           py-version: [2, 7]      # Constraint to specific interpreter version
           path: /opt/2019.2/salt  # Main Salt installation directory.
           dependencies:           # List of dependencies and their installation paths
             jinja2: /opt/jinja2
             yaml: /opt/yaml
             tornado: /opt/tornado
             msgpack: /opt/msgpack
             certifi: /opt/certifi
             singledispatch: /opt/singledispatch.py
             singledispatch_helpers: /opt/singledispatch_helpers.py
             markupsafe: /opt/markupsafe
             backports_abc: /opt/backports_abc.py

.. warning:: When using Salt versions >= 3001 and Python 2 is your py-version you need to use an older version of Salt that supports Python 2. For example, if using Salt-SSH version 3001 and you do not want to install Python 3 on your target host you can use ssh_ext_alternatives's path option. This option needs to point to a 2019.2.3 Salt installation directory on your Salt-SSH host, which still supports Python 2.

auto_detect

In the 3001 release the auto_detect feature was added for ssh_ext_alternatives. This allows salt-ssh to automatically detect the path to all of your dependencies and does not require you to define them under dependencies.

.. code-block:: yaml

   ssh_ext_alternatives:
       2019.2:                     # Namespace, can be anything.
           py-version: [2, 7]      # Constraint to specific interpreter version
           path: /opt/2019.2/salt  # Main Salt installation directory.
           auto_detect: True       # Auto detect dependencies
           py_bin: /usr/bin/python2.7 # Python binary path used to auto detect dependencies

If py_bin is not set alongside auto_detect, it will attempt to auto detect the dependencies using the major version set in py-version. For example if you have [2, 7] set as your py-version, it will attempt to use the binary python2.

You can also use auto_detect and dependencies together.

.. code-block:: yaml

   ssh_ext_alternatives:
       2019.2:                     # Namespace, can be anything.
           py-version: [2, 7]      # Constraint to specific interpreter version
           path: /opt/2019.2/salt  # Main Salt installation directory.
           auto_detect: True       # Auto detect dependencies
           py_bin: /usr/bin/python2.7 # Python binary path to auto detect dependencies
           dependencies:           # List of dependencies and their installation paths
             jinja2: /opt/jinja2

If a dependency is defined in the dependencies list ssh_ext_alternatives will use this dependency, instead of the path that auto_detect finds. For example, if you define /opt/jinja2 under your dependencies for jinja2, it will not try to autodetect the file path to the jinja2 module, and will favor /opt/jinja2.