terraform/terraform/resource.go

552 lines
16 KiB
Go

package terraform
import (
"fmt"
"reflect"
"sort"
"strconv"
"strings"
"github.com/mitchellh/copystructure"
"github.com/mitchellh/reflectwalk"
"github.com/zclconf/go-cty/cty"
"github.com/hashicorp/terraform/addrs"
"github.com/hashicorp/terraform/config"
"github.com/hashicorp/terraform/configs/configschema"
"github.com/hashicorp/terraform/configs/hcl2shim"
)
// Resource is a legacy way to identify a particular resource instance.
//
// New code should use addrs.ResourceInstance instead. This is still here
// only for codepaths that haven't been updated yet.
type Resource struct {
// These are all used by the new EvalNode stuff.
Name string
Type string
CountIndex int
// These aren't really used anymore anywhere, but we keep them around
// since we haven't done a proper cleanup yet.
Id string
Info *InstanceInfo
Config *ResourceConfig
Dependencies []string
Diff *InstanceDiff
Provider ResourceProvider
State *InstanceState
Flags ResourceFlag
}
// NewResource constructs a legacy Resource object from an
// addrs.ResourceInstance value.
//
// This is provided to shim to old codepaths that haven't been updated away
// from this type yet. Since this old type is not able to represent instances
// that have string keys, this function will panic if given a resource address
// that has a string key.
func NewResource(addr addrs.ResourceInstance) *Resource {
ret := &Resource{
Name: addr.Resource.Name,
Type: addr.Resource.Type,
}
if addr.Key != addrs.NoKey {
switch tk := addr.Key.(type) {
case addrs.IntKey:
ret.CountIndex = int(tk)
default:
panic(fmt.Errorf("resource instance with key %#v is not supported", addr.Key))
}
}
return ret
}
// ResourceKind specifies what kind of instance we're working with, whether
// its a primary instance, a tainted instance, or an orphan.
type ResourceFlag byte
// InstanceInfo is used to hold information about the instance and/or
// resource being modified.
type InstanceInfo struct {
// Id is a unique name to represent this instance. This is not related
// to InstanceState.ID in any way.
Id string
// ModulePath is the complete path of the module containing this
// instance.
ModulePath []string
// Type is the resource type of this instance
Type string
// uniqueExtra is an internal field that can be populated to supply
// extra metadata that is used to identify a unique instance in
// the graph walk. This will be appended to HumanID when uniqueId
// is called.
uniqueExtra string
}
// NewInstanceInfo constructs an InstanceInfo from an addrs.AbsResourceInstance.
//
// InstanceInfo is a legacy type, and uses of it should be gradually replaced
// by direct use of addrs.AbsResource or addrs.AbsResourceInstance as
// appropriate.
//
// The legacy InstanceInfo type cannot represent module instances with instance
// keys, so this function will panic if given such a path. Uses of this type
// should all be removed or replaced before implementing "count" and "for_each"
// arguments on modules in order to avoid such panics.
//
// This legacy type also cannot represent resource instances with string
// instance keys. It will panic if the given key is not either NoKey or an
// IntKey.
func NewInstanceInfo(addr addrs.AbsResourceInstance) *InstanceInfo {
// We need an old-style []string module path for InstanceInfo.
path := make([]string, len(addr.Module))
for i, step := range addr.Module {
if step.InstanceKey != addrs.NoKey {
panic("NewInstanceInfo cannot convert module instance with key")
}
path[i] = step.Name
}
// This is a funny old meaning of "id" that is no longer current. It should
// not be used for anything users might see. Note that it does not include
// a representation of the resource mode, and so it's impossible to
// determine from an InstanceInfo alone whether it is a managed or data
// resource that is being referred to.
id := fmt.Sprintf("%s.%s", addr.Resource.Resource.Type, addr.Resource.Resource.Name)
if addr.Resource.Resource.Mode == addrs.DataResourceMode {
id = "data." + id
}
if addr.Resource.Key != addrs.NoKey {
switch k := addr.Resource.Key.(type) {
case addrs.IntKey:
id = id + fmt.Sprintf(".%d", int(k))
default:
panic(fmt.Sprintf("NewInstanceInfo cannot convert resource instance with %T instance key", addr.Resource.Key))
}
}
return &InstanceInfo{
Id: id,
ModulePath: path,
Type: addr.Resource.Resource.Type,
}
}
// ResourceAddress returns the address of the resource that the receiver is describing.
func (i *InstanceInfo) ResourceAddress() *ResourceAddress {
// GROSS: for tainted and deposed instances, their status gets appended
// to i.Id to create a unique id for the graph node. Historically these
// ids were displayed to the user, so it's designed to be human-readable:
// "aws_instance.bar.0 (deposed #0)"
//
// So here we detect such suffixes and try to interpret them back to
// their original meaning so we can then produce a ResourceAddress
// with a suitable InstanceType.
id := i.Id
instanceType := TypeInvalid
if idx := strings.Index(id, " ("); idx != -1 {
remain := id[idx:]
id = id[:idx]
switch {
case strings.Contains(remain, "tainted"):
instanceType = TypeTainted
case strings.Contains(remain, "deposed"):
instanceType = TypeDeposed
}
}
addr, err := parseResourceAddressInternal(id)
if err != nil {
// should never happen, since that would indicate a bug in the
// code that constructed this InstanceInfo.
panic(fmt.Errorf("InstanceInfo has invalid Id %s", id))
}
if len(i.ModulePath) > 1 {
addr.Path = i.ModulePath[1:] // trim off "root" prefix, which is implied
}
if instanceType != TypeInvalid {
addr.InstanceTypeSet = true
addr.InstanceType = instanceType
}
return addr
}
// ResourceConfig is a legacy type that was formerly used to represent
// interpolatable configuration blocks. It is now only used to shim to old
// APIs that still use this type, via NewResourceConfigShimmed.
type ResourceConfig struct {
ComputedKeys []string
Raw map[string]interface{}
Config map[string]interface{}
raw *config.RawConfig
}
// NewResourceConfig creates a new ResourceConfig from a config.RawConfig.
func NewResourceConfig(c *config.RawConfig) *ResourceConfig {
result := &ResourceConfig{raw: c}
result.interpolateForce()
return result
}
// NewResourceConfigRaw constructs a ResourceConfig whose content is exactly
// the given value.
//
// The given value may contain hcl2shim.UnknownVariableValue to signal that
// something is computed, but it must not contain unprocessed interpolation
// sequences as we might've seen in Terraform v0.11 and prior.
func NewResourceConfigRaw(raw map[string]interface{}) *ResourceConfig {
v := hcl2shim.HCL2ValueFromConfigValue(raw)
// This is a little weird but we round-trip the value through the hcl2shim
// package here for two reasons: firstly, because that reduces the risk
// of it including something unlike what NewResourceConfigShimmed would
// produce, and secondly because it creates a copy of "raw" just in case
// something is relying on the fact that in the old world the raw and
// config maps were always distinct, and thus you could in principle mutate
// one without affecting the other. (I sure hope nobody was doing that, though!)
cfg := hcl2shim.ConfigValueFromHCL2(v).(map[string]interface{})
return &ResourceConfig{
Raw: raw,
Config: cfg,
ComputedKeys: newResourceConfigShimmedComputedKeys(v, ""),
}
}
// NewResourceConfigShimmed wraps a cty.Value of object type in a legacy
// ResourceConfig object, so that it can be passed to older APIs that expect
// this wrapping.
//
// The returned ResourceConfig is already interpolated and cannot be
// re-interpolated. It is, therefore, useful only to functions that expect
// an already-populated ResourceConfig which they then treat as read-only.
//
// If the given value is not of an object type that conforms to the given
// schema then this function will panic.
func NewResourceConfigShimmed(val cty.Value, schema *configschema.Block) *ResourceConfig {
if !val.Type().IsObjectType() {
panic(fmt.Errorf("NewResourceConfigShimmed given %#v; an object type is required", val.Type()))
}
ret := &ResourceConfig{}
legacyVal := hcl2shim.ConfigValueFromHCL2Block(val, schema)
if legacyVal != nil {
ret.Config = legacyVal
// Now we need to walk through our structure and find any unknown values,
// producing the separate list ComputedKeys to represent these. We use the
// schema here so that we can preserve the expected invariant
// that an attribute is always either wholly known or wholly unknown, while
// a child block can be partially unknown.
ret.ComputedKeys = newResourceConfigShimmedComputedKeys(val, "")
} else {
ret.Config = make(map[string]interface{})
}
ret.Raw = ret.Config
return ret
}
// Record the any config values in ComputedKeys. This field had been unused in
// helper/schema, but in the new protocol we're using this so that the SDK can
// now handle having an unknown collection. The legacy diff code doesn't
// properly handle the unknown, because it can't be expressed in the same way
// between the config and diff.
func newResourceConfigShimmedComputedKeys(val cty.Value, path string) []string {
var ret []string
ty := val.Type()
if val.IsNull() {
return ret
}
if !val.IsKnown() {
// we shouldn't have an entirely unknown resource, but prevent empty
// strings just in case
if len(path) > 0 {
ret = append(ret, path)
}
return ret
}
if path != "" {
path += "."
}
switch {
case ty.IsListType(), ty.IsTupleType(), ty.IsSetType():
i := 0
for it := val.ElementIterator(); it.Next(); i++ {
_, subVal := it.Element()
keys := newResourceConfigShimmedComputedKeys(subVal, fmt.Sprintf("%s%d", path, i))
ret = append(ret, keys...)
}
case ty.IsMapType(), ty.IsObjectType():
for it := val.ElementIterator(); it.Next(); {
subK, subVal := it.Element()
keys := newResourceConfigShimmedComputedKeys(subVal, fmt.Sprintf("%s%s", path, subK.AsString()))
ret = append(ret, keys...)
}
}
return ret
}
// DeepCopy performs a deep copy of the configuration. This makes it safe
// to modify any of the structures that are part of the resource config without
// affecting the original configuration.
func (c *ResourceConfig) DeepCopy() *ResourceConfig {
// DeepCopying a nil should return a nil to avoid panics
if c == nil {
return nil
}
// Copy, this will copy all the exported attributes
copy, err := copystructure.Config{Lock: true}.Copy(c)
if err != nil {
panic(err)
}
// Force the type
result := copy.(*ResourceConfig)
return result
}
// Equal checks the equality of two resource configs.
func (c *ResourceConfig) Equal(c2 *ResourceConfig) bool {
// If either are nil, then they're only equal if they're both nil
if c == nil || c2 == nil {
return c == c2
}
// Sort the computed keys so they're deterministic
sort.Strings(c.ComputedKeys)
sort.Strings(c2.ComputedKeys)
// Two resource configs if their exported properties are equal.
// We don't compare "raw" because it is never used again after
// initialization and for all intents and purposes they are equal
// if the exported properties are equal.
check := [][2]interface{}{
{c.ComputedKeys, c2.ComputedKeys},
{c.Raw, c2.Raw},
{c.Config, c2.Config},
}
for _, pair := range check {
if !reflect.DeepEqual(pair[0], pair[1]) {
return false
}
}
return true
}
// CheckSet checks that the given list of configuration keys is
// properly set. If not, errors are returned for each unset key.
//
// This is useful to be called in the Validate method of a ResourceProvider.
func (c *ResourceConfig) CheckSet(keys []string) []error {
var errs []error
for _, k := range keys {
if !c.IsSet(k) {
errs = append(errs, fmt.Errorf("%s must be set", k))
}
}
return errs
}
// Get looks up a configuration value by key and returns the value.
//
// The second return value is true if the get was successful. Get will
// return the raw value if the key is computed, so you should pair this
// with IsComputed.
func (c *ResourceConfig) Get(k string) (interface{}, bool) {
// We aim to get a value from the configuration. If it is computed,
// then we return the pure raw value.
source := c.Config
if c.IsComputed(k) {
source = c.Raw
}
return c.get(k, source)
}
// GetRaw looks up a configuration value by key and returns the value,
// from the raw, uninterpolated config.
//
// The second return value is true if the get was successful. Get will
// not succeed if the value is being computed.
func (c *ResourceConfig) GetRaw(k string) (interface{}, bool) {
return c.get(k, c.Raw)
}
// IsComputed returns whether the given key is computed or not.
func (c *ResourceConfig) IsComputed(k string) bool {
// The next thing we do is check the config if we get a computed
// value out of it.
v, ok := c.get(k, c.Config)
if !ok {
return false
}
// If value is nil, then it isn't computed
if v == nil {
return false
}
// Test if the value contains an unknown value
var w unknownCheckWalker
if err := reflectwalk.Walk(v, &w); err != nil {
panic(err)
}
return w.Unknown
}
// IsSet checks if the key in the configuration is set. A key is set if
// it has a value or the value is being computed (is unknown currently).
//
// This function should be used rather than checking the keys of the
// raw configuration itself, since a key may be omitted from the raw
// configuration if it is being computed.
func (c *ResourceConfig) IsSet(k string) bool {
if c == nil {
return false
}
if c.IsComputed(k) {
return true
}
if _, ok := c.Get(k); ok {
return true
}
return false
}
func (c *ResourceConfig) get(
k string, raw map[string]interface{}) (interface{}, bool) {
parts := strings.Split(k, ".")
if len(parts) == 1 && parts[0] == "" {
parts = nil
}
var current interface{} = raw
var previous interface{} = nil
for i, part := range parts {
if current == nil {
return nil, false
}
cv := reflect.ValueOf(current)
switch cv.Kind() {
case reflect.Map:
previous = current
v := cv.MapIndex(reflect.ValueOf(part))
if !v.IsValid() {
if i > 0 && i != (len(parts)-1) {
tryKey := strings.Join(parts[i:], ".")
v := cv.MapIndex(reflect.ValueOf(tryKey))
if !v.IsValid() {
return nil, false
}
return v.Interface(), true
}
return nil, false
}
current = v.Interface()
case reflect.Slice:
previous = current
if part == "#" {
// If any value in a list is computed, this whole thing
// is computed and we can't read any part of it.
for i := 0; i < cv.Len(); i++ {
if v := cv.Index(i).Interface(); v == hcl2shim.UnknownVariableValue {
return v, true
}
}
current = cv.Len()
} else {
i, err := strconv.ParseInt(part, 0, 0)
if err != nil {
return nil, false
}
if int(i) < 0 || int(i) >= cv.Len() {
return nil, false
}
current = cv.Index(int(i)).Interface()
}
case reflect.String:
// This happens when map keys contain "." and have a common
// prefix so were split as path components above.
actualKey := strings.Join(parts[i-1:], ".")
if prevMap, ok := previous.(map[string]interface{}); ok {
v, ok := prevMap[actualKey]
return v, ok
}
return nil, false
default:
panic(fmt.Sprintf("Unknown kind: %s", cv.Kind()))
}
}
return current, true
}
// interpolateForce is a temporary thing. We want to get rid of interpolate
// above and likewise this, but it can only be done after the f-ast-graph
// refactor is complete.
func (c *ResourceConfig) interpolateForce() {
if c.raw == nil {
// If we don't have a lowercase "raw" but we _do_ have the uppercase
// Raw populated then this indicates that we're recieving a shim
// ResourceConfig created by NewResourceConfigShimmed, which is already
// fully evaluated and thus this function doesn't need to do anything.
if c.Raw != nil {
return
}
var err error
c.raw, err = config.NewRawConfig(make(map[string]interface{}))
if err != nil {
panic(err)
}
}
c.ComputedKeys = c.raw.UnknownKeys()
c.Raw = c.raw.RawMap()
c.Config = c.raw.Config()
}
// unknownCheckWalker
type unknownCheckWalker struct {
Unknown bool
}
func (w *unknownCheckWalker) Primitive(v reflect.Value) error {
if v.Interface() == hcl2shim.UnknownVariableValue {
w.Unknown = true
}
return nil
}