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Interpreter Discovery

Most Ansible modules that execute under a POSIX environment require a Python interpreter on the target host. Unless configured otherwise, Ansible will attempt to discover a suitable Python interpreter on each target host the first time a Python module is executed for that host.

To control the discovery behavior:

  • for individual hosts and groups, use the ansible_python_interpreter inventory variable
  • globally, use the interpreter_python key in the [defaults] section of ansible.cfg

Use one of the following values:

auto_legacy : (default in 2.8)
Detects the target OS platform, distribution, and version, then consults a table listing the correct Python interpreter and path for each platform/distribution/version. If an entry is found, and /usr/bin/python is absent, uses the discovered interpreter (and path). If an entry is found, and /usr/bin/python is present, uses /usr/bin/python and issues a warning. This exception provides temporary compatibility with previous versions of Ansible that always defaulted to /usr/bin/python, so if you have installed Python and other dependencies at usr/bin/python on some hosts, Ansible will find and use them with this setting. If no entry is found, or the listed Python is not present on the target host, searches a list of common Python interpreter paths and uses the first one found; also issues a warning that future installation of another Python interpreter could alter the one chosen.
auto : (future default in 2.12)
Detects the target OS platform, distribution, and version, then consults a table listing the correct Python interpreter and path for each platform/distribution/version. If an entry is found, uses the discovered interpreter. If no entry is found, or the listed Python is not present on the target host, searches a list of common Python interpreter paths and uses the first one found; also issues a warning that future installation of another Python interpreter could alter the one chosen.
auto_legacy_silent
Same as auto_legacy, but does not issue warnings.
auto_silent
Same as auto, but does not issue warnings.

You can still set ansible_python_interpreter to a specific path at any variable level (for example, in host_vars, in vars files, in playbooks, etc.). Setting a specific path completely disables automatic interpreter discovery; Ansible always uses the path specified.