opentofu/terraform/resource_provisioner.go
Martin Atkins c937c06a03 terraform: ugly huge change to weave in new HCL2-oriented types
Due to how deeply the configuration types go into Terraform Core, there
isn't a great way to switch out to HCL2 gradually. As a consequence, this
huge commit gets us from the old state to a _compilable_ new state, but
does not yet attempt to fix any tests and has a number of known missing
parts and bugs. We will continue to iterate on this in forthcoming
commits, heading back towards passing tests and making Terraform
fully-functional again.

The three main goals here are:
- Use the configuration models from the "configs" package instead of the
  older models in the "config" package, which is now deprecated and
  preserved only to help us write our migration tool.
- Do expression inspection and evaluation using the functionality of the
  new "lang" package, instead of the Interpolator type and related
  functionality in the main "terraform" package.
- Represent addresses of various objects using types in the addrs package,
  rather than hand-constructed strings. This is not critical to support
  the above, but was a big help during the implementation of these other
  points since it made it much more explicit what kind of address is
  expected in each context.

Since our new packages are built to accommodate some future planned
features that are not yet implemented (e.g. the "for_each" argument on
resources, "count"/"for_each" on modules), and since there's still a fair
amount of functionality still using old-style APIs, there is a moderate
amount of shimming here to connect new assumptions with old, hopefully in
a way that makes it easier to find and eliminate these shims later.

I apologize in advance to the person who inevitably just found this huge
commit while spelunking through the commit history.
2018-10-16 18:46:46 -07:00

66 lines
2.8 KiB
Go

package terraform
import (
"github.com/hashicorp/terraform/config/configschema"
)
// ResourceProvisioner is an interface that must be implemented by any
// resource provisioner: the thing that initializes resources in
// a Terraform configuration.
type ResourceProvisioner interface {
// GetConfigSchema returns the schema for the provisioner type's main
// configuration block. This is called prior to Validate to enable some
// basic structural validation to be performed automatically and to allow
// the configuration to be properly extracted from potentially-ambiguous
// configuration file formats.
GetConfigSchema() (*configschema.Block, error)
// Validate is called once at the beginning with the raw
// configuration (no interpolation done) and can return a list of warnings
// and/or errors.
//
// This is called once per resource.
//
// This should not assume any of the values in the resource configuration
// are valid since it is possible they have to be interpolated still.
// The primary use case of this call is to check that the required keys
// are set and that the general structure is correct.
Validate(*ResourceConfig) ([]string, []error)
// Apply runs the provisioner on a specific resource and returns the new
// resource state along with an error. Instead of a diff, the ResourceConfig
// is provided since provisioners only run after a resource has been
// newly created.
Apply(UIOutput, *InstanceState, *ResourceConfig) error
// Stop is called when the provisioner should halt any in-flight actions.
//
// This can be used to make a nicer Ctrl-C experience for Terraform.
// Even if this isn't implemented to do anything (just returns nil),
// Terraform will still cleanly stop after the currently executing
// graph node is complete. However, this API can be used to make more
// efficient halts.
//
// Stop doesn't have to and shouldn't block waiting for in-flight actions
// to complete. It should take any action it wants and return immediately
// acknowledging it has received the stop request. Terraform core will
// automatically not make any further API calls to the provider soon
// after Stop is called (technically exactly once the currently executing
// graph nodes are complete).
//
// The error returned, if non-nil, is assumed to mean that signaling the
// stop somehow failed and that the user should expect potentially waiting
// a longer period of time.
Stop() error
}
// ResourceProvisionerCloser is an interface that provisioners that can close
// connections that aren't needed anymore must implement.
type ResourceProvisionerCloser interface {
Close() error
}
// ResourceProvisionerFactory is a function type that creates a new instance
// of a resource provisioner.
type ResourceProvisionerFactory func() (ResourceProvisioner, error)