terraform/command/format/diff.go

1022 lines
30 KiB
Go

package format
import (
"bufio"
"bytes"
"fmt"
"sort"
"strings"
"github.com/mitchellh/colorstring"
"github.com/zclconf/go-cty/cty"
ctyjson "github.com/zclconf/go-cty/cty/json"
"github.com/hashicorp/terraform/addrs"
"github.com/hashicorp/terraform/configs/configschema"
"github.com/hashicorp/terraform/plans"
"github.com/hashicorp/terraform/plans/objchange"
"github.com/hashicorp/terraform/states"
)
// ResourceChange returns a string representation of a change to a particular
// resource, for inclusion in user-facing plan output.
//
// The resource schema must be provided along with the change so that the
// formatted change can reflect the configuration structure for the associated
// resource.
//
// If "color" is non-nil, it will be used to color the result. Otherwise,
// no color codes will be included.
func ResourceChange(
change *plans.ResourceInstanceChangeSrc,
schema *configschema.Block,
color *colorstring.Colorize,
) string {
addr := change.Addr
var buf bytes.Buffer
if color == nil {
color = &colorstring.Colorize{
Colors: colorstring.DefaultColors,
Disable: true,
Reset: false,
}
}
dispAddr := addr.String()
if change.DeposedKey != states.NotDeposed {
dispAddr = fmt.Sprintf("%s (deposed object %s)", dispAddr, change.DeposedKey)
}
switch change.Action {
case plans.Create:
buf.WriteString(color.Color(fmt.Sprintf("[bold] # %s[reset] will be created", dispAddr)))
case plans.Read:
buf.WriteString(color.Color(fmt.Sprintf("[bold] # %s[reset] will be read during apply\n # (config refers to values not yet known)", dispAddr)))
case plans.Update:
buf.WriteString(color.Color(fmt.Sprintf("[bold] # %s[reset] will be updated in-place", dispAddr)))
case plans.Replace:
buf.WriteString(color.Color(fmt.Sprintf("[bold] # %s[reset] must be [bold][red]replaced", dispAddr)))
case plans.Delete:
buf.WriteString(color.Color(fmt.Sprintf("[bold] # %s[reset] will be [bold][red]destroyed", dispAddr)))
default:
// should never happen, since the above is exhaustive
buf.WriteString(fmt.Sprintf("%s has an action the plan renderer doesn't support (this is a bug)", dispAddr))
}
buf.WriteString(color.Color("[reset]\n"))
switch change.Action {
case plans.Create:
buf.WriteString(color.Color("[green] +[reset] "))
case plans.Read:
buf.WriteString(color.Color("[cyan] <=[reset] "))
case plans.Update:
buf.WriteString(color.Color("[yellow] ~[reset] "))
case plans.Replace:
buf.WriteString(color.Color("[red]-[reset]/[green]+[reset] "))
case plans.Delete:
buf.WriteString(color.Color("[red] -[reset] "))
default:
buf.WriteString(color.Color("??? "))
}
switch addr.Resource.Resource.Mode {
case addrs.ManagedResourceMode:
buf.WriteString(fmt.Sprintf(
"resource %q %q",
addr.Resource.Resource.Type,
addr.Resource.Resource.Name,
))
case addrs.DataResourceMode:
buf.WriteString(fmt.Sprintf(
"data %q %q ",
addr.Resource.Resource.Type,
addr.Resource.Resource.Name,
))
default:
// should never happen, since the above is exhaustive
buf.WriteString(addr.String())
}
buf.WriteString(" {\n")
p := blockBodyDiffPrinter{
buf: &buf,
color: color,
action: change.Action,
requiredReplace: change.RequiredReplace,
}
// Most commonly-used resources have nested blocks that result in us
// going at least three traversals deep while we recurse here, so we'll
// start with that much capacity and then grow as needed for deeper
// structures.
path := make(cty.Path, 0, 3)
changeV, err := change.Decode(schema.ImpliedType())
if err != nil {
// Should never happen in here, since we've already been through
// loads of layers of encode/decode of the planned changes before now.
panic(fmt.Sprintf("failed to decode plan for %s while rendering diff: %s", addr, err))
}
p.writeBlockBodyDiff(schema, changeV.Before, changeV.After, 6, path)
buf.WriteString(" }\n")
return buf.String()
}
type ctyValueDiff struct {
Action plans.Action
Value cty.Value
}
type blockBodyDiffPrinter struct {
buf *bytes.Buffer
color *colorstring.Colorize
action plans.Action
requiredReplace cty.PathSet
}
const forcesNewResourceCaption = " [red]# forces replacement[reset]"
func (p *blockBodyDiffPrinter) writeBlockBodyDiff(schema *configschema.Block, old, new cty.Value, indent int, path cty.Path) {
path = ctyEnsurePathCapacity(path, 1)
blankBeforeBlocks := false
{
attrNames := make([]string, 0, len(schema.Attributes))
attrNameLen := 0
for name := range schema.Attributes {
oldVal := ctyGetAttrMaybeNull(old, name)
newVal := ctyGetAttrMaybeNull(new, name)
if oldVal.IsNull() && newVal.IsNull() {
// Skip attributes where both old and new values are null
// (we do this early here so that we'll do our value alignment
// based on the longest attribute name that has a change, rather
// than the longest attribute name in the full set.)
continue
}
attrNames = append(attrNames, name)
if len(name) > attrNameLen {
attrNameLen = len(name)
}
}
sort.Strings(attrNames)
if len(attrNames) > 0 {
blankBeforeBlocks = true
}
for _, name := range attrNames {
attrS := schema.Attributes[name]
oldVal := ctyGetAttrMaybeNull(old, name)
newVal := ctyGetAttrMaybeNull(new, name)
p.writeAttrDiff(name, attrS, oldVal, newVal, attrNameLen, indent, path)
}
}
{
blockTypeNames := make([]string, 0, len(schema.BlockTypes))
for name := range schema.BlockTypes {
blockTypeNames = append(blockTypeNames, name)
}
sort.Strings(blockTypeNames)
for _, name := range blockTypeNames {
blockS := schema.BlockTypes[name]
oldVal := ctyGetAttrMaybeNull(old, name)
newVal := ctyGetAttrMaybeNull(new, name)
p.writeNestedBlockDiffs(name, blockS, oldVal, newVal, blankBeforeBlocks, indent, path)
// Always include a blank for any subsequent block types.
blankBeforeBlocks = true
}
}
}
func (p *blockBodyDiffPrinter) writeAttrDiff(name string, attrS *configschema.Attribute, old, new cty.Value, nameLen, indent int, path cty.Path) {
path = append(path, cty.GetAttrStep{Name: name})
p.buf.WriteString(strings.Repeat(" ", indent))
showJustNew := false
var action plans.Action
switch {
case old.IsNull():
action = plans.Create
showJustNew = true
case new.IsNull():
action = plans.Delete
case ctyEqualWithUnknown(old, new):
action = plans.NoOp
showJustNew = true
default:
action = plans.Update
}
p.writeActionSymbol(action)
p.buf.WriteString(p.color.Color("[bold]"))
p.buf.WriteString(name)
p.buf.WriteString(p.color.Color("[reset]"))
p.buf.WriteString(strings.Repeat(" ", nameLen-len(name)))
p.buf.WriteString(" = ")
if attrS.Sensitive {
p.buf.WriteString("(sensitive value)")
} else {
switch {
case showJustNew:
p.writeValue(new, action, indent+2)
default:
// We show new even if it is null to emphasize the fact
// that it is being unset, since otherwise it is easy to
// misunderstand that the value is still set to the old value.
p.writeValueDiff(old, new, indent+2, path)
}
}
p.buf.WriteString("\n")
}
func (p *blockBodyDiffPrinter) writeNestedBlockDiffs(name string, blockS *configschema.NestedBlock, old, new cty.Value, blankBefore bool, indent int, path cty.Path) {
path = append(path, cty.GetAttrStep{Name: name})
if old.IsNull() && new.IsNull() {
// Nothing to do if both old and new is null
return
}
// Where old/new are collections representing a nesting mode other than
// NestingSingle, we assume the collection value can never be unknown
// since we always produce the container for the nested objects, even if
// the objects within are computed.
switch blockS.Nesting {
case configschema.NestingSingle:
var action plans.Action
switch {
case old.IsNull():
action = plans.Create
case new.IsNull():
action = plans.Delete
case !new.IsKnown() || !old.IsKnown():
// "old" should actually always be known due to our contract
// that old values must never be unknown, but we'll allow it
// anyway to be robust.
action = plans.Update
case !(new.Equals(old).True()):
action = plans.Update
}
if blankBefore {
p.buf.WriteRune('\n')
}
p.writeNestedBlockDiff(name, nil, &blockS.Block, action, old, new, indent, path)
case configschema.NestingList:
// For the sake of handling nested blocks, we'll treat a null list
// the same as an empty list since the config language doesn't
// distinguish these anyway.
if old.IsNull() {
old = cty.ListValEmpty(old.Type().ElementType())
}
if new.IsNull() {
new = cty.ListValEmpty(new.Type().ElementType())
}
oldItems := ctyCollectionValues(old)
newItems := ctyCollectionValues(new)
// Here we intentionally preserve the index-based correspondance
// between old and new, rather than trying to detect insertions
// and removals in the list, because this more accurately reflects
// how Terraform Core and providers will understand the change,
// particularly when the nested block contains computed attributes
// that will themselves maintain correspondance by index.
// commonLen is number of elements that exist in both lists, which
// will be presented as updates (~). Any additional items in one
// of the lists will be presented as either creates (+) or deletes (-)
// depending on which list they belong to.
var commonLen int
switch {
case len(oldItems) < len(newItems):
commonLen = len(oldItems)
default:
commonLen = len(newItems)
}
if blankBefore && (len(oldItems) > 0 || len(newItems) > 0) {
p.buf.WriteRune('\n')
}
for i := 0; i < commonLen; i++ {
path := append(path, cty.IndexStep{Key: cty.NumberIntVal(int64(i))})
oldItem := oldItems[i]
newItem := newItems[i]
p.writeNestedBlockDiff(name, nil, &blockS.Block, plans.Update, oldItem, newItem, indent, path)
}
for i := commonLen; i < len(oldItems); i++ {
path := append(path, cty.IndexStep{Key: cty.NumberIntVal(int64(i))})
oldItem := oldItems[i]
newItem := cty.NullVal(oldItem.Type())
p.writeNestedBlockDiff(name, nil, &blockS.Block, plans.Delete, oldItem, newItem, indent, path)
}
for i := commonLen; i < len(newItems); i++ {
path := append(path, cty.IndexStep{Key: cty.NumberIntVal(int64(i))})
newItem := newItems[i]
oldItem := cty.NullVal(newItem.Type())
p.writeNestedBlockDiff(name, nil, &blockS.Block, plans.Create, oldItem, newItem, indent, path)
}
case configschema.NestingSet:
// For the sake of handling nested blocks, we'll treat a null set
// the same as an empty set since the config language doesn't
// distinguish these anyway.
if old.IsNull() {
old = cty.SetValEmpty(old.Type().ElementType())
}
if new.IsNull() {
new = cty.SetValEmpty(new.Type().ElementType())
}
oldItems := ctyCollectionValues(old)
newItems := ctyCollectionValues(new)
if (len(oldItems) + len(newItems)) == 0 {
// Nothing to do if both sets are empty
return
}
allItems := make([]cty.Value, 0, len(oldItems)+len(newItems))
allItems = append(allItems, oldItems...)
allItems = append(allItems, newItems...)
all := cty.SetVal(allItems)
if blankBefore {
p.buf.WriteRune('\n')
}
for it := all.ElementIterator(); it.Next(); {
_, val := it.Element()
var action plans.Action
var oldValue, newValue cty.Value
switch {
case !old.HasElement(val).True():
action = plans.Create
oldValue = cty.NullVal(val.Type())
newValue = val
case !new.HasElement(val).True():
action = plans.Delete
oldValue = val
newValue = cty.NullVal(val.Type())
default:
action = plans.NoOp
oldValue = val
newValue = val
}
path := append(path, cty.IndexStep{Key: val})
p.writeNestedBlockDiff(name, nil, &blockS.Block, action, oldValue, newValue, indent, path)
}
case configschema.NestingMap:
// TODO: Implement this, once helper/schema is actually able to
// produce schemas containing nested map block types.
}
}
func (p *blockBodyDiffPrinter) writeNestedBlockDiff(name string, label *string, blockS *configschema.Block, action plans.Action, old, new cty.Value, indent int, path cty.Path) {
p.buf.WriteString(strings.Repeat(" ", indent))
p.writeActionSymbol(action)
if label != nil {
fmt.Fprintf(p.buf, "%s %q {", name, label)
} else {
fmt.Fprintf(p.buf, "%s {", name)
}
if action != plans.NoOp && (p.pathForcesNewResource(path) || p.pathForcesNewResource(path[:len(path)-1])) {
p.buf.WriteString(p.color.Color(forcesNewResourceCaption))
}
p.buf.WriteString("\n")
p.writeBlockBodyDiff(blockS, old, new, indent+4, path)
p.buf.WriteString(strings.Repeat(" ", indent+2))
p.buf.WriteString("}\n")
}
func (p *blockBodyDiffPrinter) writeValue(val cty.Value, action plans.Action, indent int) {
if !val.IsKnown() {
p.buf.WriteString("(known after apply)")
return
}
if val.IsNull() {
p.buf.WriteString("null")
return
}
ty := val.Type()
switch {
case ty.IsPrimitiveType():
switch ty {
case cty.String:
{
// Special behavior for JSON strings containing array or object
src := []byte(val.AsString())
ty, err := ctyjson.ImpliedType(src)
if err == nil && !ty.IsPrimitiveType() {
jv, err := ctyjson.Unmarshal(src, ty)
if err == nil {
p.buf.WriteString("jsonencode(")
p.buf.WriteByte('\n')
p.buf.WriteString(strings.Repeat(" ", indent+4))
p.writeValue(jv, action, indent+4)
p.buf.WriteByte('\n')
p.buf.WriteString(strings.Repeat(" ", indent))
p.buf.WriteByte(')')
break // don't *also* do the normal behavior below
}
}
}
fmt.Fprintf(p.buf, "%q", val.AsString())
case cty.Bool:
if val.True() {
p.buf.WriteString("true")
} else {
p.buf.WriteString("false")
}
case cty.Number:
bf := val.AsBigFloat()
p.buf.WriteString(bf.Text('f', -1))
default:
// should never happen, since the above is exhaustive
fmt.Fprintf(p.buf, "%#v", val)
}
case ty.IsListType() || ty.IsSetType() || ty.IsTupleType():
p.buf.WriteString("[\n")
it := val.ElementIterator()
for it.Next() {
_, val := it.Element()
p.buf.WriteString(strings.Repeat(" ", indent+2))
p.writeActionSymbol(action)
p.writeValue(val, action, indent+4)
p.buf.WriteString(",\n")
}
p.buf.WriteString(strings.Repeat(" ", indent))
p.buf.WriteString("]")
case ty.IsMapType():
p.buf.WriteString("{\n")
keyLen := 0
for it := val.ElementIterator(); it.Next(); {
key, _ := it.Element()
if keyStr := key.AsString(); len(keyStr) > keyLen {
keyLen = len(keyStr)
}
}
for it := val.ElementIterator(); it.Next(); {
key, val := it.Element()
p.buf.WriteString(strings.Repeat(" ", indent+2))
p.writeActionSymbol(action)
p.writeValue(key, action, indent+4)
p.buf.WriteString(strings.Repeat(" ", keyLen-len(key.AsString())))
p.buf.WriteString(" = ")
p.writeValue(val, action, indent+4)
p.buf.WriteString("\n")
}
p.buf.WriteString(strings.Repeat(" ", indent))
p.buf.WriteString("}")
case ty.IsObjectType():
p.buf.WriteString("{\n")
atys := ty.AttributeTypes()
attrNames := make([]string, 0, len(atys))
nameLen := 0
for attrName := range atys {
attrNames = append(attrNames, attrName)
if len(attrName) > nameLen {
nameLen = len(attrName)
}
}
sort.Strings(attrNames)
for _, attrName := range attrNames {
val := val.GetAttr(attrName)
p.buf.WriteString(strings.Repeat(" ", indent+2))
p.writeActionSymbol(action)
p.buf.WriteString(attrName)
p.buf.WriteString(strings.Repeat(" ", nameLen-len(attrName)))
p.buf.WriteString(" = ")
p.writeValue(val, action, indent+4)
p.buf.WriteString("\n")
}
p.buf.WriteString(strings.Repeat(" ", indent))
p.buf.WriteString("}")
}
}
func (p *blockBodyDiffPrinter) writeValueDiff(old, new cty.Value, indent int, path cty.Path) {
ty := old.Type()
// We have some specialized diff implementations for certain complex
// values where it's useful to see a visualization of the diff of
// the nested elements rather than just showing the entire old and
// new values verbatim.
// However, these specialized implementations can apply only if both
// values are known and non-null.
if old.IsKnown() && new.IsKnown() && !old.IsNull() && !new.IsNull() {
switch {
// TODO: object diffs that behave a bit like the map diffs, including if the two object types don't exactly match
case ty == cty.String:
// We have special behavior for both multi-line strings in general
// and for strings that can parse as JSON. For the JSON handling
// to apply, both old and new must be valid JSON.
// For single-line strings that don't parse as JSON we just fall
// out of this switch block and do the default old -> new rendering.
oldS := old.AsString()
newS := new.AsString()
{
// Special behavior for JSON strings containing object or
// list values.
oldBytes := []byte(oldS)
newBytes := []byte(newS)
oldType, oldErr := ctyjson.ImpliedType(oldBytes)
newType, newErr := ctyjson.ImpliedType(newBytes)
if oldErr == nil && newErr == nil && !(oldType.IsPrimitiveType() && newType.IsPrimitiveType()) {
oldJV, oldErr := ctyjson.Unmarshal(oldBytes, oldType)
newJV, newErr := ctyjson.Unmarshal(newBytes, newType)
if oldErr == nil && newErr == nil {
if !oldJV.RawEquals(newJV) { // two JSON values may differ only in insignificant whitespace
p.buf.WriteString("jsonencode(")
p.buf.WriteByte('\n')
p.buf.WriteString(strings.Repeat(" ", indent+2))
p.writeActionSymbol(plans.Update)
p.writeValueDiff(oldJV, newJV, indent+4, path)
p.buf.WriteByte('\n')
p.buf.WriteString(strings.Repeat(" ", indent))
p.buf.WriteByte(')')
} else {
// if they differ only in insigificant whitespace
// then we'll note that but still expand out the
// effective value.
if p.pathForcesNewResource(path) {
p.buf.WriteString(p.color.Color("jsonencode( [red]# whitespace changes force replacement[reset]"))
} else {
p.buf.WriteString(p.color.Color("jsonencode( [dim]# whitespace changes[reset]"))
}
p.buf.WriteByte('\n')
p.buf.WriteString(strings.Repeat(" ", indent+4))
p.writeValue(oldJV, plans.NoOp, indent+4)
p.buf.WriteByte('\n')
p.buf.WriteString(strings.Repeat(" ", indent))
p.buf.WriteByte(')')
}
return
}
}
}
if strings.Index(oldS, "\n") < 0 && strings.Index(newS, "\n") < 0 {
break
}
p.buf.WriteString("<<~EOT")
if p.pathForcesNewResource(path) {
p.buf.WriteString(p.color.Color(forcesNewResourceCaption))
}
p.buf.WriteString("\n")
var oldLines, newLines []cty.Value
{
r := strings.NewReader(oldS)
sc := bufio.NewScanner(r)
for sc.Scan() {
oldLines = append(oldLines, cty.StringVal(sc.Text()))
}
}
{
r := strings.NewReader(newS)
sc := bufio.NewScanner(r)
for sc.Scan() {
newLines = append(newLines, cty.StringVal(sc.Text()))
}
}
diffLines := ctySequenceDiff(oldLines, newLines)
for _, diffLine := range diffLines {
line := diffLine.Value.AsString()
switch diffLine.Action {
case plans.Create:
p.buf.WriteString(strings.Repeat(" ", indent+2))
p.buf.WriteString(p.color.Color("[green]+[reset] "))
p.buf.WriteString(line)
p.buf.WriteString("\n")
case plans.Delete:
p.buf.WriteString(strings.Repeat(" ", indent+2))
p.buf.WriteString(p.color.Color("[red]-[reset] "))
p.buf.WriteString(line)
p.buf.WriteString("\n")
case plans.NoOp:
p.buf.WriteString(strings.Repeat(" ", indent+2))
p.buf.WriteString(p.color.Color(" "))
p.buf.WriteString(line)
p.buf.WriteString("\n")
default:
// Should never happen since the above covers all
// actions that ctySequenceDiff can return.
p.buf.WriteString(strings.Repeat(" ", indent+2))
p.buf.WriteString(p.color.Color("? "))
p.buf.WriteString(line)
p.buf.WriteString("\n")
}
}
p.buf.WriteString(strings.Repeat(" ", indent)) // +4 here because there's no symbol
p.buf.WriteString("EOT")
return
case ty.IsSetType():
p.buf.WriteString("[")
if p.pathForcesNewResource(path) {
p.buf.WriteString(p.color.Color(forcesNewResourceCaption))
}
p.buf.WriteString("\n")
var addedVals, removedVals, allVals []cty.Value
for it := old.ElementIterator(); it.Next(); {
_, val := it.Element()
allVals = append(allVals, val)
if new.HasElement(val).False() {
removedVals = append(removedVals, val)
}
}
for it := new.ElementIterator(); it.Next(); {
_, val := it.Element()
allVals = append(allVals, val)
if old.HasElement(val).False() {
addedVals = append(addedVals, val)
}
}
var all, added, removed cty.Value
if len(allVals) > 0 {
all = cty.SetVal(allVals)
} else {
all = cty.SetValEmpty(ty.ElementType())
}
if len(addedVals) > 0 {
added = cty.SetVal(addedVals)
} else {
added = cty.SetValEmpty(ty.ElementType())
}
if len(removedVals) > 0 {
removed = cty.SetVal(removedVals)
} else {
removed = cty.SetValEmpty(ty.ElementType())
}
for it := all.ElementIterator(); it.Next(); {
_, val := it.Element()
p.buf.WriteString(strings.Repeat(" ", indent+2))
var action plans.Action
switch {
case added.HasElement(val).True():
action = plans.Create
case removed.HasElement(val).True():
action = plans.Delete
default:
action = plans.NoOp
}
p.writeActionSymbol(action)
p.writeValue(val, action, indent+4)
p.buf.WriteString(",\n")
}
p.buf.WriteString(strings.Repeat(" ", indent))
p.buf.WriteString("]")
return
case ty.IsListType() || ty.IsTupleType():
p.buf.WriteString("[")
if p.pathForcesNewResource(path) {
p.buf.WriteString(p.color.Color(forcesNewResourceCaption))
}
p.buf.WriteString("\n")
elemDiffs := ctySequenceDiff(old.AsValueSlice(), new.AsValueSlice())
for _, elemDiff := range elemDiffs {
p.buf.WriteString(strings.Repeat(" ", indent+2))
p.writeActionSymbol(elemDiff.Action)
p.writeValue(elemDiff.Value, elemDiff.Action, indent+4)
p.buf.WriteString(",\n")
}
p.buf.WriteString(strings.Repeat(" ", indent))
p.buf.WriteString("]")
return
case ty.IsMapType():
p.buf.WriteString("{")
if p.pathForcesNewResource(path) {
p.buf.WriteString(p.color.Color(forcesNewResourceCaption))
}
p.buf.WriteString("\n")
var allKeys []string
keyLen := 0
for it := old.ElementIterator(); it.Next(); {
k, _ := it.Element()
keyStr := k.AsString()
allKeys = append(allKeys, keyStr)
if len(keyStr) > keyLen {
keyLen = len(keyStr)
}
}
for it := new.ElementIterator(); it.Next(); {
k, _ := it.Element()
keyStr := k.AsString()
allKeys = append(allKeys, keyStr)
if len(keyStr) > keyLen {
keyLen = len(keyStr)
}
}
sort.Strings(allKeys)
lastK := ""
for i, k := range allKeys {
if i > 0 && lastK == k {
continue // skip duplicates (list is sorted)
}
lastK = k
p.buf.WriteString(strings.Repeat(" ", indent+2))
kV := cty.StringVal(k)
var action plans.Action
if old.HasIndex(kV).False() {
action = plans.Create
} else if new.HasIndex(kV).False() {
action = plans.Delete
} else if eqV := old.Index(kV).Equals(new.Index(kV)); eqV.IsKnown() && eqV.True() {
action = plans.NoOp
} else {
action = plans.Update
}
path := append(path, cty.IndexStep{Key: kV})
p.writeActionSymbol(action)
p.writeValue(kV, action, indent+4)
p.buf.WriteString(strings.Repeat(" ", keyLen-len(k)))
p.buf.WriteString(" = ")
switch action {
case plans.Create, plans.NoOp:
v := new.Index(kV)
p.writeValue(v, action, indent+4)
case plans.Delete:
oldV := old.Index(kV)
newV := cty.NullVal(oldV.Type())
p.writeValueDiff(oldV, newV, indent+4, path)
default:
oldV := old.Index(kV)
newV := new.Index(kV)
p.writeValueDiff(oldV, newV, indent+4, path)
}
p.buf.WriteByte('\n')
}
p.buf.WriteString(strings.Repeat(" ", indent))
p.buf.WriteString("}")
return
}
}
// In all other cases, we just show the new and old values as-is
p.writeValue(old, plans.Delete, indent)
p.buf.WriteString(p.color.Color(" [yellow]->[reset] "))
p.writeValue(new, plans.Create, indent)
if p.pathForcesNewResource(path) {
p.buf.WriteString(p.color.Color(forcesNewResourceCaption))
}
}
// writeActionSymbol writes a symbol to represent the given action, followed
// by a space.
//
// It only supports the actions that can be represented with a single character:
// Create, Delete, Update and NoAction.
func (p *blockBodyDiffPrinter) writeActionSymbol(action plans.Action) {
switch action {
case plans.Create:
p.buf.WriteString(p.color.Color("[green]+[reset] "))
case plans.Delete:
p.buf.WriteString(p.color.Color("[red]-[reset] "))
case plans.Update:
p.buf.WriteString(p.color.Color("[yellow]~[reset] "))
case plans.NoOp:
p.buf.WriteString(" ")
default:
// Should never happen
p.buf.WriteString(p.color.Color("? "))
}
}
func (p *blockBodyDiffPrinter) pathForcesNewResource(path cty.Path) bool {
if p.action != plans.Replace {
// "requiredReplace" only applies when the instance is being replaced
return false
}
return p.requiredReplace.Has(path)
}
func ctyGetAttrMaybeNull(val cty.Value, name string) cty.Value {
if val.IsNull() {
ty := val.Type().AttributeType(name)
return cty.NullVal(ty)
}
return val.GetAttr(name)
}
func ctyCollectionValues(val cty.Value) []cty.Value {
ret := make([]cty.Value, 0, val.LengthInt())
for it := val.ElementIterator(); it.Next(); {
_, value := it.Element()
ret = append(ret, value)
}
return ret
}
func ctySequenceDiff(old, new []cty.Value) []ctyValueDiff {
var ret []ctyValueDiff
lcs := objchange.LongestCommonSubsequence(old, new)
var oldI, newI, lcsI int
for oldI < len(old) || newI < len(new) || lcsI < len(lcs) {
for oldI < len(old) && (lcsI >= len(lcs) || !old[oldI].RawEquals(lcs[lcsI])) {
ret = append(ret, ctyValueDiff{
Action: plans.Delete,
Value: old[oldI],
})
oldI++
}
for newI < len(new) && (lcsI >= len(lcs) || !new[newI].RawEquals(lcs[lcsI])) {
ret = append(ret, ctyValueDiff{
Action: plans.Create,
Value: new[newI],
})
newI++
}
if lcsI < len(lcs) {
ret = append(ret, ctyValueDiff{
Action: plans.NoOp,
Value: new[newI],
})
// All of our indexes advance together now, since the line
// is common to all three sequences.
lcsI++
oldI++
newI++
}
}
return ret
}
// ctyObjectSequenceDiff is a variant of ctySequenceDiff that only works for
// values of object types. Whereas ctySequenceDiff can only return Create
// and Delete actions, this function can additionally return Update actions
// heuristically based on similarity of objects in the lists, which must
// be greater than or equal to the caller-specified threshold.
//
// See ctyObjectSimilarity for details on what "similarity" means here.
func ctyObjectSequenceDiff(old, new []cty.Value, threshold float64) []*plans.Change {
var ret []*plans.Change
lcs := objchange.LongestCommonSubsequence(old, new)
var oldI, newI, lcsI int
for oldI < len(old) || newI < len(new) || lcsI < len(lcs) {
for oldI < len(old) && (lcsI >= len(lcs) || !old[oldI].RawEquals(lcs[lcsI])) {
if newI < len(new) {
// See if the next "new" is similar enough to our "old" that
// we'll treat this as an Update rather than a Delete/Create.
similarity := ctyObjectSimilarity(old[oldI], new[newI])
if similarity >= threshold {
ret = append(ret, &plans.Change{
Action: plans.Update,
Before: old[oldI],
After: new[newI],
})
oldI++
newI++ // we also consume the next "new" in this case
continue
}
}
ret = append(ret, &plans.Change{
Action: plans.Delete,
Before: old[oldI],
After: cty.NullVal(old[oldI].Type()),
})
oldI++
}
for newI < len(new) && (lcsI >= len(lcs) || !new[newI].RawEquals(lcs[lcsI])) {
ret = append(ret, &plans.Change{
Action: plans.Create,
Before: cty.NullVal(new[newI].Type()),
After: new[newI],
})
newI++
}
if lcsI < len(lcs) {
ret = append(ret, &plans.Change{
Action: plans.NoOp,
Before: new[newI],
After: new[newI],
})
// All of our indexes advance together now, since the line
// is common to all three sequences.
lcsI++
oldI++
newI++
}
}
return ret
}
// ctyObjectSimilarity returns a number between 0 and 1 that describes
// approximately how similar the two given values are, comparing in terms of
// how many of the corresponding attributes have the same value in both
// objects.
//
// This function expects the two values to have a similar set of attribute
// names, though doesn't mind if the two slightly differ since it will
// count missing attributes as differences.
//
// This function will panic if either of the given values is not an object.
func ctyObjectSimilarity(old, new cty.Value) float64 {
oldType := old.Type()
newType := new.Type()
attrNames := make(map[string]struct{})
for name := range oldType.AttributeTypes() {
attrNames[name] = struct{}{}
}
for name := range newType.AttributeTypes() {
attrNames[name] = struct{}{}
}
matches := 0
for name := range attrNames {
if !oldType.HasAttribute(name) {
continue
}
if !newType.HasAttribute(name) {
continue
}
eq := old.GetAttr(name).Equals(new.GetAttr(name))
if !eq.IsKnown() {
continue
}
if eq.True() {
matches++
}
}
return float64(matches) / float64(len(attrNames))
}
func ctyEqualWithUnknown(old, new cty.Value) bool {
if !old.IsKnown() || !new.IsKnown() {
return false
}
return old.Equals(new).True()
}
func ctyEnsurePathCapacity(path cty.Path, minExtra int) cty.Path {
if cap(path)-len(path) >= minExtra {
return path
}
newCap := cap(path) * 2
if newCap < (len(path) + minExtra) {
newCap = len(path) + minExtra
}
newPath := make(cty.Path, len(path), newCap)
copy(newPath, path)
return newPath
}