package schema
import (
"fmt"
"github.com/hashicorp/terraform/config/configschema"
"github.com/zclconf/go-cty/cty"
)
// The functions and methods in this file are concerned with the conversion
// of this package's schema model into the slightly-lower-level schema model
// used by Terraform core for configuration parsing.
// CoreConfigSchema lowers the receiver to the schema model expected by
// Terraform core.
//
// This lower-level model has fewer features than the schema in this package,
// describing only the basic structure of configuration and state values we
// expect. The full schemaMap from this package is still required for full
// validation, handling of default values, etc.
//
// This method presumes a schema that passes InternalValidate, and so may
// panic or produce an invalid result if given an invalid schemaMap.
func (m schemaMap) CoreConfigSchema() *configschema.Block {
if len(m) == 0 {
// We return an actual (empty) object here, rather than a nil,
// because a nil result would mean that we don't have a schema at
// all, rather than that we have an empty one.
return &configschema.Block{}
}
ret := &configschema.Block{
Attributes: map[string]*configschema.Attribute{},
BlockTypes: map[string]*configschema.NestedBlock{},
}
for name, schema := range m {
if schema.Elem == nil {
ret.Attributes[name] = schema.coreConfigSchemaAttribute()
continue
}
switch schema.Elem.(type) {
case *Schema:
ret.Attributes[name] = schema.coreConfigSchemaAttribute()
case *Resource:
ret.BlockTypes[name] = schema.coreConfigSchemaBlock()
default:
// Should never happen for a valid schema
panic(fmt.Errorf("invalid Schema.Elem %#v; need *Schema or *Resource", schema.Elem))
}
}
return ret
}
// coreConfigSchemaAttribute prepares a configschema.Attribute representation
// of a schema. This is appropriate only for primitives or collections whose
// Elem is an instance of Schema. Use coreConfigSchemaBlock for collections
// whose elem is a whole resource.
func (s *Schema) coreConfigSchemaAttribute() *configschema.Attribute {
return &configschema.Attribute{
Type: s.coreConfigSchemaType(),
Optional: s.Optional,
Required: s.Required,
Computed: s.Computed,
Sensitive: s.Sensitive,
}
}
// coreConfigSchemaBlock prepares a configschema.NestedBlock representation of
// a schema. This is appropriate only for collections whose Elem is an instance
// of Resource, and will panic otherwise.
func (s *Schema) coreConfigSchemaBlock() *configschema.NestedBlock {
ret := &configschema.NestedBlock{}
if nested := s.Elem.(*Resource).CoreConfigSchema(); nested != nil {
ret.Block = *nested
}
switch s.Type {
case TypeList:
ret.Nesting = configschema.NestingList
case TypeSet:
ret.Nesting = configschema.NestingSet
case TypeMap:
ret.Nesting = configschema.NestingMap
default:
// Should never happen for a valid schema
panic(fmt.Errorf("invalid s.Type %s for s.Elem being resource", s.Type))
}
ret.MinItems = s.MinItems
ret.MaxItems = s.MaxItems
if s.Required && s.MinItems == 0 {
// configschema doesn't have a "required" representation for nested
// blocks, but we can fake it by requiring at least one item.
ret.MinItems = 1
}
return ret
}
// coreConfigSchemaType determines the core config schema type that corresponds
// to a particular schema's type.
func (s *Schema) coreConfigSchemaType() cty.Type {
switch s.Type {
case TypeString:
return cty.String
case TypeBool:
return cty.Bool
case TypeInt, TypeFloat:
// configschema doesn't distinguish int and float, so helper/schema
// will deal with this as an additional validation step after
// configuration has been parsed and decoded.
return cty.Number
case TypeList, TypeSet, TypeMap:
var elemType cty.Type
switch set := s.Elem.(type) {
case *Schema:
elemType = set.coreConfigSchemaType()
case *Resource:
// In practice we don't actually use this for normal schema
// construction because we construct a NestedBlock in that
// case instead. See schemaMap.CoreConfigSchema.
elemType = set.CoreConfigSchema().ImpliedType()
default:
if set != nil {
// Should never happen for a valid schema
panic(fmt.Errorf("invalid Schema.Elem %#v; need *Schema or *Resource", s.Elem))
}
// Some pre-existing schemas assume string as default, so we need
// to be compatible with them.
elemType = cty.String
}
switch s.Type {
case TypeList:
return cty.List(elemType)
case TypeSet:
return cty.Set(elemType)
case TypeMap:
return cty.Map(elemType)
default:
// can never get here in practice, due to the case we're inside
panic("invalid collection type")
}
default:
// should never happen for a valid schema
panic(fmt.Errorf("invalid Schema.Type %s", s.Type))
}
}
// CoreConfigSchema is a convenient shortcut for calling CoreConfigSchema
// on the resource's schema.
func (r *Resource) CoreConfigSchema() *configschema.Block {
return schemaMap(r.Schema).CoreConfigSchema()
}
