terraform/helper/schema/resource_data.go

408 lines
10 KiB
Go

package schema
import (
"reflect"
"strings"
"sync"
"github.com/hashicorp/terraform/terraform"
)
// ResourceData is used to query and set the attributes of a resource.
//
// ResourceData is the primary argument received for CRUD operations on
// a resource as well as configuration of a provider. It is a powerful
// structure that can be used to not only query data, but check for changes,
// define partial state updates, etc.
//
// The most relevant methods to take a look at are Get, Set, and Partial.
type ResourceData struct {
// Settable (internally)
schema map[string]*Schema
config *terraform.ResourceConfig
state *terraform.InstanceState
diff *terraform.InstanceDiff
// Don't set
multiReader *MultiLevelFieldReader
setWriter *MapFieldWriter
newState *terraform.InstanceState
partial bool
partialMap map[string]struct{}
once sync.Once
}
// getResult is the internal structure that is generated when a Get
// is called that contains some extra data that might be used.
type getResult struct {
Value interface{}
ValueProcessed interface{}
Computed bool
Exists bool
Schema *Schema
}
var getResultEmpty getResult
// Get returns the data for the given key, or nil if the key doesn't exist
// in the schema.
//
// If the key does exist in the schema but doesn't exist in the configuration,
// then the default value for that type will be returned. For strings, this is
// "", for numbers it is 0, etc.
//
// If you want to test if something is set at all in the configuration,
// use GetOk.
func (d *ResourceData) Get(key string) interface{} {
v, _ := d.GetOk(key)
return v
}
// GetChange returns the old and new value for a given key.
//
// HasChange should be used to check if a change exists. It is possible
// that both the old and new value are the same if the old value was not
// set and the new value is. This is common, for example, for boolean
// fields which have a zero value of false.
func (d *ResourceData) GetChange(key string) (interface{}, interface{}) {
o, n := d.getChange(key, getSourceState, getSourceDiff)
return o.Value, n.Value
}
// GetOk returns the data for the given key and whether or not the key
// has been set to a non-zero value at some point.
//
// The first result will not necessarilly be nil if the value doesn't exist.
// The second result should be checked to determine this information.
func (d *ResourceData) GetOk(key string) (interface{}, bool) {
r := d.getRaw(key, getSourceSet)
exists := r.Exists && !r.Computed
if exists {
// If it exists, we also want to verify it is not the zero-value.
value := r.Value
zero := r.Schema.Type.Zero()
if eq, ok := value.(Equal); ok {
exists = !eq.Equal(zero)
} else {
exists = !reflect.DeepEqual(value, zero)
}
}
return r.Value, exists
}
func (d *ResourceData) getRaw(key string, level getSource) getResult {
var parts []string
if key != "" {
parts = strings.Split(key, ".")
}
return d.get(parts, level)
}
// HasChange returns whether or not the given key has been changed.
func (d *ResourceData) HasChange(key string) bool {
o, n := d.GetChange(key)
// If the type implements the Equal interface, then call that
// instead of just doing a reflect.DeepEqual. An example where this is
// needed is *Set
if eq, ok := o.(Equal); ok {
return !eq.Equal(n)
}
return !reflect.DeepEqual(o, n)
}
// Partial turns partial state mode on/off.
//
// When partial state mode is enabled, then only key prefixes specified
// by SetPartial will be in the final state. This allows providers to return
// partial states for partially applied resources (when errors occur).
func (d *ResourceData) Partial(on bool) {
d.partial = on
if on {
if d.partialMap == nil {
d.partialMap = make(map[string]struct{})
}
} else {
d.partialMap = nil
}
}
// Set sets the value for the given key.
//
// If the key is invalid or the value is not a correct type, an error
// will be returned.
func (d *ResourceData) Set(key string, value interface{}) error {
d.once.Do(d.init)
// If the value is a pointer to a non-struct, get its value and
// use that. This allows Set to take a pointer to primitives to
// simplify the interface.
reflectVal := reflect.ValueOf(value)
if reflectVal.Kind() == reflect.Ptr {
if reflectVal.IsNil() {
// If the pointer is nil, then the value is just nil
value = nil
} else {
// Otherwise, we dereference the pointer as long as its not
// a pointer to a struct, since struct pointers are allowed.
reflectVal = reflect.Indirect(reflectVal)
if reflectVal.Kind() != reflect.Struct {
value = reflectVal.Interface()
}
}
}
return d.setWriter.WriteField(strings.Split(key, "."), value)
}
// SetPartial adds the key to the final state output while
// in partial state mode. The key must be a root key in the schema (i.e.
// it cannot be "list.0").
//
// If partial state mode is disabled, then this has no effect. Additionally,
// whenever partial state mode is toggled, the partial data is cleared.
func (d *ResourceData) SetPartial(k string) {
if d.partial {
d.partialMap[k] = struct{}{}
}
}
// Id returns the ID of the resource.
func (d *ResourceData) Id() string {
var result string
if d.state != nil {
result = d.state.ID
}
if d.newState != nil {
result = d.newState.ID
}
return result
}
// ConnInfo returns the connection info for this resource.
func (d *ResourceData) ConnInfo() map[string]string {
if d.newState != nil {
return d.newState.Ephemeral.ConnInfo
}
if d.state != nil {
return d.state.Ephemeral.ConnInfo
}
return nil
}
// SetId sets the ID of the resource. If the value is blank, then the
// resource is destroyed.
func (d *ResourceData) SetId(v string) {
d.once.Do(d.init)
d.newState.ID = v
}
// SetConnInfo sets the connection info for a resource.
func (d *ResourceData) SetConnInfo(v map[string]string) {
d.once.Do(d.init)
d.newState.Ephemeral.ConnInfo = v
}
// State returns the new InstanceState after the diff and any Set
// calls.
func (d *ResourceData) State() *terraform.InstanceState {
var result terraform.InstanceState
result.ID = d.Id()
// If we have no ID, then this resource doesn't exist and we just
// return nil.
if result.ID == "" {
return nil
}
// In order to build the final state attributes, we read the full
// attribute set as a map[string]interface{}, write it to a MapFieldWriter,
// and then use that map.
rawMap := make(map[string]interface{})
for k := range d.schema {
source := getSourceSet
if d.partial {
source = getSourceState
if _, ok := d.partialMap[k]; ok {
source = getSourceSet
}
}
raw := d.get([]string{k}, source)
if raw.Exists && !raw.Computed {
rawMap[k] = raw.Value
if raw.ValueProcessed != nil {
rawMap[k] = raw.ValueProcessed
}
}
}
mapW := &MapFieldWriter{Schema: d.schema}
if err := mapW.WriteField(nil, rawMap); err != nil {
return nil
}
result.Attributes = mapW.Map()
result.Ephemeral.ConnInfo = d.ConnInfo()
// TODO: This is hacky and we can remove this when we have a proper
// state writer. We should instead have a proper StateFieldWriter
// and use that.
for k, schema := range d.schema {
if schema.Type != TypeMap {
continue
}
if result.Attributes[k] == "" {
delete(result.Attributes, k)
}
}
if v := d.Id(); v != "" {
result.Attributes["id"] = d.Id()
}
return &result
}
func (d *ResourceData) init() {
// Initialize the field that will store our new state
var copyState terraform.InstanceState
if d.state != nil {
copyState = *d.state
}
d.newState = &copyState
// Initialize the map for storing set data
d.setWriter = &MapFieldWriter{Schema: d.schema}
// Initialize the reader for getting data from the
// underlying sources (config, diff, etc.)
readers := make(map[string]FieldReader)
var stateAttributes map[string]string
if d.state != nil {
stateAttributes = d.state.Attributes
readers["state"] = &MapFieldReader{
Schema: d.schema,
Map: BasicMapReader(stateAttributes),
}
}
if d.config != nil {
readers["config"] = &ConfigFieldReader{
Schema: d.schema,
Config: d.config,
}
}
if d.diff != nil {
readers["diff"] = &DiffFieldReader{
Schema: d.schema,
Diff: d.diff,
Source: &MultiLevelFieldReader{
Levels: []string{"state", "config"},
Readers: readers,
},
}
}
readers["set"] = &MapFieldReader{
Schema: d.schema,
Map: BasicMapReader(d.setWriter.Map()),
}
d.multiReader = &MultiLevelFieldReader{
Levels: []string{
"state",
"config",
"diff",
"set",
},
Readers: readers,
}
}
func (d *ResourceData) diffChange(
k string) (interface{}, interface{}, bool, bool) {
// Get the change between the state and the config.
o, n := d.getChange(k, getSourceState, getSourceConfig|getSourceExact)
if !o.Exists {
o.Value = nil
}
if !n.Exists {
n.Value = nil
}
// Return the old, new, and whether there is a change
return o.Value, n.Value, !reflect.DeepEqual(o.Value, n.Value), n.Computed
}
func (d *ResourceData) getChange(
k string,
oldLevel getSource,
newLevel getSource) (getResult, getResult) {
var parts, parts2 []string
if k != "" {
parts = strings.Split(k, ".")
parts2 = strings.Split(k, ".")
}
o := d.get(parts, oldLevel)
n := d.get(parts2, newLevel)
return o, n
}
func (d *ResourceData) get(addr []string, source getSource) getResult {
d.once.Do(d.init)
level := "set"
flags := source & ^getSourceLevelMask
exact := flags&getSourceExact != 0
source = source & getSourceLevelMask
if source >= getSourceSet {
level = "set"
} else if source >= getSourceDiff {
level = "diff"
} else if source >= getSourceConfig {
level = "config"
} else {
level = "state"
}
var result FieldReadResult
var err error
if exact {
result, err = d.multiReader.ReadFieldExact(addr, level)
} else {
result, err = d.multiReader.ReadFieldMerge(addr, level)
}
if err != nil {
panic(err)
}
// If the result doesn't exist, then we set the value to the zero value
var schema *Schema
if schemaL := addrToSchema(addr, d.schema); len(schemaL) > 0 {
schema = schemaL[len(schemaL)-1]
}
if result.Value == nil && schema != nil {
result.Value = result.ValueOrZero(schema)
}
// Transform the FieldReadResult into a getResult. It might be worth
// merging these two structures one day.
return getResult{
Value: result.Value,
ValueProcessed: result.ValueProcessed,
Computed: result.Computed,
Exists: result.Exists,
Schema: schema,
}
}