package schema import ( "errors" "fmt" "github.com/hashicorp/terraform/terraform" ) // Resource represents a thing in Terraform that has a set of configurable // attributes and a lifecycle (create, read, update, delete). // // The Resource schema is an abstraction that allows provider writers to // worry only about CRUD operations while off-loading validation, diff // generation, etc. to this higher level library. type Resource struct { // Schema is the schema for the configuration of this resource. // // The keys of this map are the configuration keys, and the values // describe the schema of the configuration value. // // The schema is used to represent both configurable data as well // as data that might be computed in the process of creating this // resource. Schema map[string]*Schema // The functions below are the CRUD operations for this resource. // // The only optional operation is Update. If Update is not implemented, // then updates will not be supported for this resource. // // The ResourceData parameter in the functions below are used to // query configuration and changes for the resource as well as to set // the ID, computed data, etc. // // The interface{} parameter is the result of the ConfigureFunc in // the provider for this resource. If the provider does not define // a ConfigureFunc, this will be nil. This parameter should be used // to store API clients, configuration structures, etc. // // If any errors occur during each of the operation, an error should be // returned. If a resource was partially updated, be careful to enable // partial state mode for ResourceData and use it accordingly. Create CreateFunc Read ReadFunc Update UpdateFunc Delete DeleteFunc } // See Resource documentation. type CreateFunc func(*ResourceData, interface{}) error // See Resource documentation. type ReadFunc func(*ResourceData, interface{}) error // See Resource documentation. type UpdateFunc func(*ResourceData, interface{}) error // See Resource documentation. type DeleteFunc func(*ResourceData, interface{}) error // Apply creates, updates, and/or deletes a resource. func (r *Resource) Apply( s *terraform.InstanceState, d *terraform.ResourceDiff, meta interface{}) (*terraform.InstanceState, error) { data, err := schemaMap(r.Schema).Data(s, d) if err != nil { return s, err } if s == nil { // The Terraform API dictates that this should never happen, but // it doesn't hurt to be safe in this case. s = new(terraform.InstanceState) } if d.Destroy || d.RequiresNew() { if s.ID != "" { // Destroy the resource since it is created if err := r.Delete(data, meta); err != nil { return data.State(), err } // Make sure the ID is gone. data.SetId("") } // If we're only destroying, and not creating, then return // now since we're done! if !d.RequiresNew() { return nil, nil } } err = nil if data.Id() == "" { // We're creating, it is a new resource. err = r.Create(data, meta) } else { if r.Update == nil { return s, fmt.Errorf("doesn't support update") } err = r.Update(data, meta) } return data.State(), err } // Diff returns a diff of this resource and is API compatible with the // ResourceProvider interface. func (r *Resource) Diff( s *terraform.InstanceState, c *terraform.ResourceConfig) (*terraform.ResourceDiff, error) { return schemaMap(r.Schema).Diff(s, c) } // Validate validates the resource configuration against the schema. func (r *Resource) Validate(c *terraform.ResourceConfig) ([]string, []error) { return schemaMap(r.Schema).Validate(c) } // Refresh refreshes the state of the resource. func (r *Resource) Refresh( s *terraform.InstanceState, meta interface{}) (*terraform.InstanceState, error) { data, err := schemaMap(r.Schema).Data(s, nil) if err != nil { return s, err } err = r.Read(data, meta) state := data.State() if state != nil && state.ID == "" { state = nil } return state, err } // InternalValidate should be called to validate the structure // of the resource. // // This should be called in a unit test for any resource to verify // before release that a resource is properly configured for use with // this library. // // Provider.InternalValidate() will automatically call this for all of // the resources it manages, so you don't need to call this manually if it // is part of a Provider. func (r *Resource) InternalValidate() error { if r == nil { return errors.New("resource is nil") } return schemaMap(r.Schema).InternalValidate() }