Templates

Templates

awless writing operations to the cloud infrastructure relies on the concepts of templates. A template in awless describes a list of actions updating the cloud. For instance, this would be a one-liner template:

create instance subnet=subnet-356d517f image=ami-70edb016 type=t2.micro key=$keypair

This one line template contains an action create on an entity followed by a list of params.

Parameters can be either:

• given directly through the command line as key=value arguments
• filled transparently filled by your local config defaults (i.e: instance ami, instance type, etc...)
• completed through dynamic CLI prompting for missing required arguments

Under the hood, an awless template is parsed with a parsing expression grammar used to build an abstract syntax tree executed by an AWS cloud driver.

awless templates are used with shortcut commands (for example, awless create instance) or by launching a template file with awless run.

Commands

awless provides multiple shortcut commands to edit the cloud infrastructure using templates:

• awless create allow to create a cloud resource (ex: instance, vpc, user, ssh keypair, routetable...). It may requires multiple parameters in order to create the resource.
• awless delete allow to delete a cloud resource. It generally requires only the id of the resource to delete.
• awless update allow to update a cloud resource property after its creation. It requires at least the id of the resource to update and to set the property to update.
• awless attach allow to attach a cloud resource (for example, a volume) to another (for example an instance). It generally requires the id of those two cloud resources.
• awless detach allow to attach two attached cloud resources.
• awless start allow to start a cloud resource (for example, an instance). It requires the id of the resource to start.
• awless stop allow to stop a cloud resource (for example, an instance). It requires the id of the resource to stop.

Template file

awless can also load more complex templates combining multiple commands in a template file.