terraform/helper/schema/schema.go

466 lines
10 KiB
Go

package schema
import (
"fmt"
"strings"
"github.com/hashicorp/terraform/terraform"
"github.com/mitchellh/mapstructure"
)
// ValueType is an enum of the type that can be represented by a schema.
type ValueType int
const (
TypeInvalid ValueType = iota
TypeBool
TypeInt
TypeString
TypeList
)
// Schema is used to describe the structure of a value.
type Schema struct {
// Type is the type of the value and must be one of the ValueType values.
Type ValueType
// If one of these is set, then this item can come from the configuration.
// Both cannot be set. If Optional is set, the value is optional. If
// Required is set, the value is required.
Optional bool
Required bool
// The fields below relate to diffs.
//
// If Computed is true, then the result of this value is computed
// (unless specified by config) on creation.
//
// If ForceNew is true, then a change in this resource necessitates
// the creation of a new resource.
Computed bool
ForceNew bool
// The following fields are only set for a TypeList Type.
//
// Elem must be either a *Schema or a *Resource only if the Type is
// TypeList, and represents what the element type is. If it is *Schema,
// the element type is just a simple value. If it is *Resource, the
// element type is a complex structure, potentially with its own lifecycle.
Elem interface{}
// ComputedWhen is a set of queries on the configuration. Whenever any
// of these things is changed, it will require a recompute (this requires
// that Computed is set to true).
ComputedWhen []string
}
func (s *Schema) finalizeDiff(
d *terraform.ResourceAttrDiff) *terraform.ResourceAttrDiff {
if d == nil {
return d
}
if s.Computed {
if d.Old != "" && d.New == "" {
// This is a computed value with an old value set already,
// just let it go.
return nil
}
if d.New == "" {
// Computed attribute without a new value set
d.NewComputed = true
}
}
if s.ForceNew {
// Force new, set it to true in the diff
d.RequiresNew = true
}
return d
}
// schemaMap is a wrapper that adds nice functions on top of schemas.
type schemaMap map[string]*Schema
// Data returns a ResourceData for the given schema, state, and diff.
//
// The diff is optional.
func (m schemaMap) Data(
s *terraform.ResourceState,
d *terraform.ResourceDiff) (*ResourceData, error) {
return &ResourceData{
schema: m,
state: s,
diff: d,
}, nil
}
// Diff returns the diff for a resource given the schema map,
// state, and configuration.
func (m schemaMap) Diff(
s *terraform.ResourceState,
c *terraform.ResourceConfig) (*terraform.ResourceDiff, error) {
result := new(terraform.ResourceDiff)
result.Attributes = make(map[string]*terraform.ResourceAttrDiff)
for k, schema := range m {
err := m.diff(k, schema, result, s, c)
if err != nil {
return nil, err
}
}
// Remove any nil diffs just to keep things clean
for k, v := range result.Attributes {
if v == nil {
delete(result.Attributes, k)
}
}
// Go through and detect all of the ComputedWhens now that we've
// finished the diff.
// TODO
if result.Empty() {
// If we don't have any diff elements, just return nil
return nil, nil
}
return result, nil
}
// Validate validates the configuration against this schema mapping.
func (m schemaMap) Validate(c *terraform.ResourceConfig) ([]string, []error) {
return m.validateObject("", m, c)
}
// InternalValidate validates the format of this schema. This should be called
// from a unit test (and not in user-path code) to verify that a schema
// is properly built.
func (m schemaMap) InternalValidate() error {
for k, v := range m {
if v.Type == TypeInvalid {
return fmt.Errorf("%s: Type must be specified", k)
}
if v.Optional && v.Required {
return fmt.Errorf("%s: Optional or Required must be set, not both", k)
}
if v.Required && v.Computed {
return fmt.Errorf("%s: Cannot be both Required and Computed", k)
}
if len(v.ComputedWhen) > 0 && !v.Computed {
return fmt.Errorf("%s: ComputedWhen can only be set with Computed", k)
}
if v.Type == TypeList {
if v.Elem == nil {
return fmt.Errorf("%s: Elem must be set for lists", k)
}
switch t := v.Elem.(type) {
case *Resource:
if err := t.InternalValidate(); err != nil {
return err
}
case *Schema:
bad := t.Computed || t.Optional || t.Required
if bad {
return fmt.Errorf(
"%s: Elem must have only Type set", k)
}
}
}
}
return nil
}
func (m schemaMap) diff(
k string,
schema *Schema,
diff *terraform.ResourceDiff,
s *terraform.ResourceState,
c *terraform.ResourceConfig) error {
var err error
switch schema.Type {
case TypeBool:
fallthrough
case TypeInt:
fallthrough
case TypeString:
err = m.diffString(k, schema, diff, s, c)
case TypeList:
err = m.diffList(k, schema, diff, s, c)
default:
err = fmt.Errorf("%s: unknown type %s", k, schema.Type)
}
return err
}
func (m schemaMap) diffList(
k string,
schema *Schema,
diff *terraform.ResourceDiff,
s *terraform.ResourceState,
c *terraform.ResourceConfig) error {
v, ok := c.Get(k)
if !ok {
// We don't have a value, if it is required then it is an error
if schema.Required {
return fmt.Errorf("%s: required field not set", k)
}
// We don't have a configuration value.
if !schema.Computed {
return nil
}
}
vs, ok := v.([]interface{})
if !ok {
return fmt.Errorf("%s: must be a list", k)
}
// If this field is required, then it must also be non-empty
if len(vs) == 0 && schema.Required {
return fmt.Errorf("%s: required field is not set", k)
}
// Diff the count no matter what
countSchema := &Schema{
Type: TypeInt,
ForceNew: schema.ForceNew,
}
m.diffString(k+".#", countSchema, diff, s, c)
switch t := schema.Elem.(type) {
case *Schema:
// Copy the schema so that we can set Computed/ForceNew from
// the parent schema (the TypeList).
t2 := *t
t2.Computed = schema.Computed
t2.ForceNew = schema.ForceNew
// This is just a primitive element, so go through each and
// just diff each.
for i, _ := range vs {
subK := fmt.Sprintf("%s.%d", k, i)
err := m.diff(subK, &t2, diff, s, c)
if err != nil {
return err
}
}
case *Resource:
// This is a complex resource
for i, _ := range vs {
for k2, schema := range t.Schema {
subK := fmt.Sprintf("%s.%d.%s", k, i, k2)
err := m.diff(subK, schema, diff, s, c)
if err != nil {
return err
}
}
}
default:
return fmt.Errorf("%s: unknown element type (internal)", k)
}
return nil
}
func (m schemaMap) diffString(
k string,
schema *Schema,
diff *terraform.ResourceDiff,
s *terraform.ResourceState,
c *terraform.ResourceConfig) error {
var old, n string
if s != nil {
old = s.Attributes[k]
}
v, ok := c.Get(k)
if !ok {
// We don't have a value, if it is required then it is an error
if schema.Required {
return fmt.Errorf("%s: required field not set", k)
}
// We don't have a configuration value.
if !schema.Computed {
return nil
}
} else {
if err := mapstructure.WeakDecode(v, &n); err != nil {
return fmt.Errorf("%s: %s", k, err)
}
if old == n {
// They're the same value
return nil
}
}
diff.Attributes[k] = schema.finalizeDiff(&terraform.ResourceAttrDiff{
Old: old,
New: n,
})
return nil
}
func (m schemaMap) diffPrimitive(
k string,
nraw interface{},
schema *Schema,
diff *terraform.ResourceDiff,
s *terraform.ResourceState) error {
var old, n string
if s != nil {
old = s.Attributes[k]
}
if err := mapstructure.WeakDecode(nraw, &n); err != nil {
return fmt.Errorf("%s: %s", k, err)
}
if old == n {
// They're the same value
return nil
}
diff.Attributes[k] = schema.finalizeDiff(&terraform.ResourceAttrDiff{
Old: old,
New: n,
})
return nil
}
func (m schemaMap) validate(
k string,
schema *Schema,
c *terraform.ResourceConfig) ([]string, []error) {
raw, ok := c.Get(k)
if !ok {
if schema.Required {
return nil, []error{fmt.Errorf(
"%s: required field is not set", k)}
}
return nil, nil
}
if !schema.Required && !schema.Optional {
// This is a computed-only field
return nil, []error{fmt.Errorf(
"%s: this field cannot be set", k)}
}
return m.validatePrimitive(k, raw, schema, c)
}
func (m schemaMap) validateList(
k string,
raw interface{},
schema *Schema,
c *terraform.ResourceConfig) ([]string, []error) {
raws, ok := raw.([]interface{})
if !ok {
return nil, []error{fmt.Errorf(
"%s: should be list", k)}
}
var ws []string
var es []error
for i, raw := range raws {
key := fmt.Sprintf("%s.%d", k, i)
var ws2 []string
var es2 []error
switch t := schema.Elem.(type) {
case *Resource:
// This is a sub-resource
ws2, es2 = m.validateObject(key, t.Schema, c)
case *Schema:
// This is some sort of primitive
ws2, es2 = m.validatePrimitive(key, raw, t, c)
}
if len(ws2) > 0 {
ws = append(ws, ws2...)
}
if len(es2) > 0 {
es = append(es, es2...)
}
}
return ws, es
}
func (m schemaMap) validateObject(
k string,
schema map[string]*Schema,
c *terraform.ResourceConfig) ([]string, []error) {
var ws []string
var es []error
for subK, s := range schema {
key := subK
if k != "" {
key = fmt.Sprintf("%s.%s", k, subK)
}
ws2, es2 := m.validate(key, s, c)
if len(ws2) > 0 {
ws = append(ws, ws2...)
}
if len(es2) > 0 {
es = append(es, es2...)
}
}
// Detect any extra/unknown keys and report those as errors.
prefix := k + "."
for configK, _ := range c.Raw {
if k != "" {
if !strings.HasPrefix(configK, prefix) {
continue
}
configK = configK[len(prefix):]
}
if _, ok := schema[configK]; !ok {
es = append(es, fmt.Errorf(
"%s: invalid or unknown key: %s", k, configK))
}
}
return ws, es
}
func (m schemaMap) validatePrimitive(
k string,
raw interface{},
schema *Schema,
c *terraform.ResourceConfig) ([]string, []error) {
switch schema.Type {
case TypeList:
return m.validateList(k, raw, schema, c)
case TypeInt:
// Verify that we can parse this as an int
var n int
if err := mapstructure.WeakDecode(raw, &n); err != nil {
return nil, []error{err}
}
}
return nil, nil
}