sceptre.resolvers package

exception sceptre.resolvers.RecursiveGet

Bases: exceptions.Exception

class sceptre.resolvers.ResolvableProperty(name)

Bases: object

This is a descriptor class used to store an attribute that may contain Resolver objects. When retrieving the dictionary or list, any Resolver objects contains are a value or within a list are resolved to a primitive type. Supports nested dictionary and lists.

Parameters:name (str) – Attribute suffix used to store the property in the instance.

class ResolveLater(instance, name, key, resolution_function)

Bases: object

Represents a value that could not yet be resolved but can be resolved in the future.

class sceptre.resolvers.Resolver(argument=None, stack=None)

Bases: object

Resolver is an abstract base class that should be inherited by all Resolvers.

Parameters:

• argument (str) – The argument of the resolver.
• stack (sceptre.stack.Stack) – The associated stack of the resolver.

resolve()

An abstract method which must be overwritten by all inheriting classes. This method is called to retrieve the final desired value. Implementation of this method in subclasses must return a suitable object or primitive type.

setup()

This method is called at during stack initialisation. Implementation of this method in subclasses can be used to do any initial setup of the object.

Submodules

sceptre.resolvers.environment_variable module

class sceptre.resolvers.environment_variable.EnvironmentVariable(*args, **kwargs)

Bases: sceptre.resolvers.Resolver

Resolver for shell environment variables.

Parameters:argument (str) – Name of the environment variable to return.

resolve()

Retrieves the value of a named environment variable.

Returns:Value of the environment variable. Return type:str

sceptre.resolvers.file_contents module

class sceptre.resolvers.file_contents.FileContents(*args, **kwargs)

Bases: sceptre.resolvers.Resolver

Resolver for the contents of a file.

Parameters:argument (str) – Absolute path to file.

resolve()

Retrieves the contents of a file at a given absolute file path.

Returns:Contents of file. Return type:str

sceptre.resolvers.stack_output module

class sceptre.resolvers.stack_output.StackOutput(*args, **kwargs)

Bases: sceptre.resolvers.stack_output.StackOutputBase

Resolver for retrieving the value of a Stack output within the current Sceptre StackGroup. Adds the target Stack to the dependencies of the Stack using the Resolver.

Parameters:argument (str in the format "<stack name>::<output key>") – The Stack name and output name to get.

resolve()

Retrieves the value of an output of an internal Stack.

Returns:The value of the Stack output. Return type:str

setup()

Adds dependency to a Stack.

class sceptre.resolvers.stack_output.StackOutputBase(*args, **kwargs)

Bases: sceptre.resolvers.Resolver

A abstract base class which provides methods for getting Stack outputs.

class sceptre.resolvers.stack_output.StackOutputExternal(*args, **kwargs)

Bases: sceptre.resolvers.stack_output.StackOutputBase

Resolver for retrieving the value of an output of any Stack within the current Sceptre stack_group’s account and region.

Parameters:argument (str in the format "<full stack name>::<output key>") – The Stack name and output name to get.

resolve()

Retrieves the value of CloudFormation output of the external Stack

Returns:The value of the Stack output. Return type:str