Ensembles are meant to be self-contained and independent of their environment with any environment-dependent values and settings placed in the Ensemble’s context.
Unfurl projects define these contexts and assign them to the project’s ensembles.
Contexts can contain:
An isolated execution environment to run the ensemble’s job in. This can be directory to a Python virtual environment or a Docker container. If this is missing, it will look a Python virtual environment directory (
.venv) in the project’s directory. By default, Unfurl will create a Python virtual environment in
~/unfurl_home when the home project is created.
Specifies the runtimes environment variables to set or copy from the current environment (see Environment)
Locals are properties specific to the local environment (e.g. proxy settings) and are accessed through the local expression function.
A map of connection templates containing account credentials to use. Inherited connection templates can be renamed locally by including an item with the new name as its key and old name as its the value.
This specifies instances and connections that will be imported from external ensembles. See External ensembles.
Inheritance and precedence¶
A Unfurl project can set context defaults. It can also declare named contexts and associate ensembles with a named context.
An Ensemble can also declare what properties and values it is expecting in its context along with defaults.
The following search order is applied when looking context up settings and objects:
named context in current project
named context in home project
defaults in current project
defaults in home projects
context section in the ensemble manifest
The External section of the manifest lets you declare instances that are imported from external manifests. Instances listed here can be accessed in two ways: One, they will be implicitly used if they match a node template that is declared abstract using the “select” directive (see “3.4.3 Directives”). Two, they can be explicitly referenced using the External expression function.
There are 3 instances that are always implicitly imported even if they are not declared:
localhostinstance that represents the machine Unfurl is currently executing on. This instance is accessed through the
ORCHESTRATORkeyword in TOSCA and is defined in the home manifest that resides in your Unfurl home folder.
A map specifying the location of the manifest. It must contain a
filekey with the path to the ensemble and optionally either a
repositorykey indicating the name of the repository where the file is located or a
projectkey to indicate the project the ensemble is in.
(default: “*”) The name of the instance within the ensemble to make available. If
*all instances in the ensemble will be available.
uriof the ensemble. If it is set and it doesn’t match the retrieved ensemble’s URI a validation error will occur.
Locals and secrets:
a map of the providing the names and values of locals or secrets
a JSON schema properties object describing the schema for each attribute. If missing, validation of the attributes will be skipped.
After running “init” your Unfurl project will look like:
ensemble/ensemble.yaml ensemble-template.yaml unfurl.yaml local/unfurl.yaml
If the –existing option is used, the project will be added to the nearest repository found in a parent folder. If the –mono option is used, the ensemble add the project repo instead of it’s own.
Each repository created will also have .gitignore and .gitattributes added.
When a repository is added as child of another repo, that folder will be added to .git/info/exclude (instead of .gitignore because they shouldn’t be committed into the repository).
Include directives, imports, and external file reference are guaranteed to be local to the project. Paths outside the project need to be referenced with a named repository. Paths are always relative but you can optionally specify which repository a path is relative to.
There are three predefined repositories:
“self”, which represents the location the ensemble lives in – it will be a “git-local:” URL or a “file:” URL if the ensemble is not part of a git repository.
“unfurl” which points to the Python package of the unfurl process – this can be used to load configurators and templates that ship with Unfurl.
“spec” which, unless explicitly declared, defaults to the project root or the ensemble itself if it is not part of a project.