Give support for new Mistral environment variables when installing the undercloud.

Sometimes developers will need to use additional values inside Mistral tasks. For example, if we need to create a dump of a database we might need another one than the Mistral user credentials for authentication purposes.

Initially when the Undercloud is installed it’s created a Mistral environment called tripleo.undercloud-config. This environment variable will have all required configuration details that we can get from Mistral. This is defined in the instack-undercloud repository.

Let’s get into the repository and check the content of the file instack_undercloud/

This file defines a set of methods to interact with the Undercloud, specifically the method called _create_mistral_config_environment allows to configure additional environment variables when installing the Undercloud.

For additional testing, you can use the Python snippet to call Mistral client from the Undercloud node available in