package states import ( "github.com/zclconf/go-cty/cty" ctyjson "github.com/zclconf/go-cty/cty/json" "github.com/hashicorp/terraform/addrs" "github.com/hashicorp/terraform/config/hcl2shim" ) // ResourceInstanceObjectSrc is a not-fully-decoded version of // ResourceInstanceObject. Decoding of it can be completed by first handling // any schema migration steps to get to the latest schema version and then // calling method Decode with the implied type of the latest schema. type ResourceInstanceObjectSrc struct { // SchemaVersion is the resource-type-specific schema version number that // was current when either AttrsJSON or AttrsFlat was encoded. Migration // steps are required if this is less than the current version number // reported by the corresponding provider. SchemaVersion uint64 // AttrsJSON is a JSON-encoded representation of the object attributes, // encoding the value (of the object type implied by the associated resource // type schema) that represents this remote object in Terraform Language // expressions, and is compared with configuration when producing a diff. // // This is retained in JSON format here because it may require preprocessing // before decoding if, for example, the stored attributes are for an older // schema version which the provider must upgrade before use. If the // version is current, it is valid to simply decode this using the // type implied by the current schema, without the need for the provider // to perform an upgrade first. // // When writing a ResourceInstanceObject into the state, AttrsJSON should // always be conformant to the current schema version and the current // schema version should be recorded in the SchemaVersion field. AttrsJSON []byte // AttrsFlat is a legacy form of attributes used in older state file // formats, and in the new state format for objects that haven't yet been // upgraded. This attribute is mutually exclusive with Attrs: for any // ResourceInstanceObject, only one of these attributes may be populated // and the other must be nil. // // An instance object with this field populated should be upgraded to use // Attrs at the earliest opportunity, since this legacy flatmap-based // format will be phased out over time. AttrsFlat should not be used when // writing new or updated objects to state; instead, callers must follow // the recommendations in the AttrsJSON documentation above. AttrsFlat map[string]string // These fields all correspond to the fields of the same name on // ResourceInstanceObject. Private []byte Status ObjectStatus Dependencies []addrs.Referenceable } // Decode unmarshals the raw representation of the object attributes. Pass the // implied type of the corresponding resource type schema for correct operation. // // Before calling Decode, the caller must check that the SchemaVersion field // exactly equals the version number of the schema whose implied type is being // passed, or else the result is undefined. // // The returned object may share internal references with the receiver and // so the caller must not mutate the receiver any further once once this // method is called. func (os *ResourceInstanceObjectSrc) Decode(ty cty.Type) (*ResourceInstanceObject, error) { var val cty.Value var err error if os.AttrsFlat != nil { // Legacy mode. We'll do our best to unpick this from the flatmap. val, err = hcl2shim.HCL2ValueFromFlatmap(os.AttrsFlat, ty) if err != nil { return nil, err } } else { val, err = ctyjson.Unmarshal(os.AttrsJSON, ty) if err != nil { return nil, err } } return &ResourceInstanceObject{ Value: val, Status: os.Status, Dependencies: os.Dependencies, Private: os.Private, }, nil }