terraform/helper/schema/shims.go

159 lines
4.8 KiB
Go

package schema
import (
"encoding/json"
"fmt"
"github.com/hashicorp/terraform/config"
"github.com/hashicorp/terraform/config/hcl2shim"
"github.com/hashicorp/terraform/configs/configschema"
"github.com/hashicorp/terraform/terraform"
"github.com/zclconf/go-cty/cty"
ctyjson "github.com/zclconf/go-cty/cty/json"
)
// DiffFromValues takes the current state and desired state as cty.Values and
// derives a terraform.InstanceDiff to give to the legacy providers. This is
// used to take the states provided by the new ApplyResourceChange method and
// convert them to a state+diff required for the legacy Apply method.
func DiffFromValues(prior, planned cty.Value, res *Resource) (*terraform.InstanceDiff, error) {
return diffFromValues(prior, planned, res, nil)
}
// diffFromValues takes an additional CustomizeDiffFunc, so we can generate our
// test fixtures from the legacy tests. In the new provider protocol the diff
// only needs to be created for the apply operation, and any customizations
// have already been done.
func diffFromValues(prior, planned cty.Value, res *Resource, cust CustomizeDiffFunc) (*terraform.InstanceDiff, error) {
instanceState := InstanceStateFromStateValue(prior, res.SchemaVersion)
configSchema := res.CoreConfigSchema()
cfg := terraform.NewResourceConfigShimmed(planned, configSchema)
return schemaMap(res.Schema).Diff(instanceState, cfg, cust, nil)
}
// ApplyDiff takes a cty.Value state and applies a terraform.InstanceDiff to
// get a new cty.Value state. This is used to convert the diff returned from
// the legacy provider Diff method to the state required for the new
// PlanResourceChange method.
func ApplyDiff(state cty.Value, d *terraform.InstanceDiff, schemaBlock *configschema.Block) (cty.Value, error) {
// No diff means the state is unchanged.
if d.Empty() {
return state, nil
}
// Create an InstanceState attributes from our existing state.
// We can use this to more easily apply the diff changes.
attrs := hcl2shim.FlatmapValueFromHCL2(state)
if attrs == nil {
attrs = map[string]string{}
}
if d.Destroy || d.DestroyDeposed || d.DestroyTainted {
// to mark a destroy, we remove all attributes
attrs = map[string]string{}
}
for attr, diff := range d.Attributes {
old, exists := attrs[attr]
if old != diff.Old && exists {
return state, fmt.Errorf("mismatched diff: %q != %q", old, diff.Old)
}
if diff.NewComputed {
attrs[attr] = config.UnknownVariableValue
continue
}
if diff.NewRemoved {
delete(attrs, attr)
continue
}
attrs[attr] = diff.New
}
val, err := hcl2shim.HCL2ValueFromFlatmap(attrs, schemaBlock.ImpliedType())
if err != nil {
return val, err
}
return schemaBlock.CoerceValue(val)
}
// StateValueToJSONMap converts a cty.Value to generic JSON map via the cty JSON
// encoding.
func StateValueToJSONMap(val cty.Value, ty cty.Type) (map[string]interface{}, error) {
js, err := ctyjson.Marshal(val, ty)
if err != nil {
return nil, err
}
var m map[string]interface{}
if err := json.Unmarshal(js, &m); err != nil {
return nil, err
}
return m, nil
}
// JSONMapToStateValue takes a generic json map[string]interface{} and converts it
// to the specific type, ensuring that the values conform to the schema.
func JSONMapToStateValue(m map[string]interface{}, block *configschema.Block) (cty.Value, error) {
var val cty.Value
js, err := json.Marshal(m)
if err != nil {
return val, err
}
val, err = ctyjson.Unmarshal(js, block.ImpliedType())
if err != nil {
return val, err
}
return block.CoerceValue(val)
}
// StateValueFromInstanceState converts a terraform.InstanceState to a
// cty.Value as described by the provided cty.Type, and maintains the resource
// ID as the "id" attribute.
func StateValueFromInstanceState(is *terraform.InstanceState, ty cty.Type) (cty.Value, error) {
if is == nil {
// if the state is nil, we need to construct a complete cty.Value with
// null attributes, rather than a single cty.NullVal(ty)
is = &terraform.InstanceState{}
}
// make sure ID is included in the attributes. The InstanceState.ID value
// takes precedent.
if is.Attributes == nil {
is.Attributes = map[string]string{}
}
if is.ID != "" {
is.Attributes["id"] = is.ID
}
return hcl2shim.HCL2ValueFromFlatmap(is.Attributes, ty)
}
// InstanceStateFromStateValue converts a cty.Value to a
// terraform.InstanceState. This function requires the schema version used by
// the provider, because the legacy providers used the private Meta data in the
// InstanceState to store the schema version.
func InstanceStateFromStateValue(state cty.Value, schemaVersion int) *terraform.InstanceState {
attrs := hcl2shim.FlatmapValueFromHCL2(state)
return &terraform.InstanceState{
ID: attrs["id"],
Attributes: attrs,
Meta: map[string]interface{}{
"schema_version": schemaVersion,
},
}
}