Using a template to update a stack of resources

A non-transitory computer-readable medium storing program instructions that are executed by one or more processors to implement a service provider component configured to:

• instantiate a stack of resources that operate together to provide at least one network-accessible service, the stack of resources associated with a first template;
• receive a request to update the stack of resources, the request including a second template that specifies at least a desired end state for the stack of resources;
• compute one or more differences for one or more resources in the stack, the one or more differences introduced by the second template;
• determine, based at least in part on one or more computed differences, a set of changes to the resources of the stack;
• determine whether the changes can be implemented as a running update or require a destructive update;
• if the changes can be implemented as the running update, modify the resources while the resources are running, otherwise if the changes require the destructive update:
• create at least one new resource,
• add the new resource into the stack, and
• remove a previous version of said resource from the stack;
• and
• if the request to update the stack is unsuccessful, roll back any changes that have been made to the resources of the stack in order to return the stack to a state specified in the first template.

A system, comprising:

• one or more processors;
• and
• program instructions that are executed by one or more processors to implement a service provider component configured to:
• instantiate a stack of resources that operate together to provide at least one network-accessible service, the stack of resources being associated with a first template;
• receive a request to update the stack of resources, the request including a second template that specifies at least a desired end state for the stack of resources;
• compute one or more differences for one or more resources in the stack, the one or more differences introduced by the second template;
• determine, based at least in part on one or more computed differences, a set of changes to the resources of the stack;
• determine whether the changes can be implemented as a running update or require a destructive update;
• if the changes can be implemented as the running update, modify the resources while the resources are running, otherwise if the changes require the destructive update:
• create at least one new resource,
• add the new resource into the stack, and
• remove a previous version of said resource from the stack;
• and
• if the request to update the stack is unsuccessful, roll back any changes that have been made to the resources of the stack in order to return the stack to a state specified in the first template.