terraform/lang/funcs/collection.go

692 lines
20 KiB
Go

package funcs
import (
"errors"
"fmt"
"math/big"
"sort"
"github.com/zclconf/go-cty/cty"
"github.com/zclconf/go-cty/cty/convert"
"github.com/zclconf/go-cty/cty/function"
"github.com/zclconf/go-cty/cty/function/stdlib"
"github.com/zclconf/go-cty/cty/gocty"
)
var LengthFunc = function.New(&function.Spec{
Params: []function.Parameter{
{
Name: "value",
Type: cty.DynamicPseudoType,
AllowDynamicType: true,
AllowUnknown: true,
},
},
Type: func(args []cty.Value) (cty.Type, error) {
collTy := args[0].Type()
switch {
case collTy == cty.String || collTy.IsTupleType() || collTy.IsObjectType() || collTy.IsListType() || collTy.IsMapType() || collTy.IsSetType() || collTy == cty.DynamicPseudoType:
return cty.Number, nil
default:
return cty.Number, errors.New("argument must be a string, a collection type, or a structural type")
}
},
Impl: func(args []cty.Value, retType cty.Type) (cty.Value, error) {
coll := args[0]
collTy := args[0].Type()
switch {
case collTy == cty.DynamicPseudoType:
return cty.UnknownVal(cty.Number), nil
case collTy.IsTupleType():
l := len(collTy.TupleElementTypes())
return cty.NumberIntVal(int64(l)), nil
case collTy.IsObjectType():
l := len(collTy.AttributeTypes())
return cty.NumberIntVal(int64(l)), nil
case collTy == cty.String:
// We'll delegate to the cty stdlib strlen function here, because
// it deals with all of the complexities of tokenizing unicode
// grapheme clusters.
return stdlib.Strlen(coll)
case collTy.IsListType() || collTy.IsSetType() || collTy.IsMapType():
return coll.Length(), nil
default:
// Should never happen, because of the checks in our Type func above
return cty.UnknownVal(cty.Number), errors.New("impossible value type for length(...)")
}
},
})
// AllTrueFunc constructs a function that returns true if all elements of the
// list are true. If the list is empty, return true.
var AllTrueFunc = function.New(&function.Spec{
Params: []function.Parameter{
{
Name: "list",
Type: cty.List(cty.Bool),
},
},
Type: function.StaticReturnType(cty.Bool),
Impl: func(args []cty.Value, retType cty.Type) (ret cty.Value, err error) {
result := cty.True
for it := args[0].ElementIterator(); it.Next(); {
_, v := it.Element()
if !v.IsKnown() {
return cty.UnknownVal(cty.Bool), nil
}
if v.IsNull() {
return cty.False, nil
}
result = result.And(v)
if result.False() {
return cty.False, nil
}
}
return result, nil
},
})
// AnyTrueFunc constructs a function that returns true if any element of the
// list is true. If the list is empty, return false.
var AnyTrueFunc = function.New(&function.Spec{
Params: []function.Parameter{
{
Name: "list",
Type: cty.List(cty.Bool),
},
},
Type: function.StaticReturnType(cty.Bool),
Impl: func(args []cty.Value, retType cty.Type) (ret cty.Value, err error) {
result := cty.False
var hasUnknown bool
for it := args[0].ElementIterator(); it.Next(); {
_, v := it.Element()
if !v.IsKnown() {
hasUnknown = true
continue
}
if v.IsNull() {
continue
}
result = result.Or(v)
if result.True() {
return cty.True, nil
}
}
if hasUnknown {
return cty.UnknownVal(cty.Bool), nil
}
return result, nil
},
})
// CoalesceFunc constructs a function that takes any number of arguments and
// returns the first one that isn't empty. This function was copied from go-cty
// stdlib and modified so that it returns the first *non-empty* non-null element
// from a sequence, instead of merely the first non-null.
var CoalesceFunc = function.New(&function.Spec{
Params: []function.Parameter{},
VarParam: &function.Parameter{
Name: "vals",
Type: cty.DynamicPseudoType,
AllowUnknown: true,
AllowDynamicType: true,
AllowNull: true,
},
Type: func(args []cty.Value) (ret cty.Type, err error) {
argTypes := make([]cty.Type, len(args))
for i, val := range args {
argTypes[i] = val.Type()
}
retType, _ := convert.UnifyUnsafe(argTypes)
if retType == cty.NilType {
return cty.NilType, errors.New("all arguments must have the same type")
}
return retType, nil
},
Impl: func(args []cty.Value, retType cty.Type) (ret cty.Value, err error) {
for _, argVal := range args {
// We already know this will succeed because of the checks in our Type func above
argVal, _ = convert.Convert(argVal, retType)
if !argVal.IsKnown() {
return cty.UnknownVal(retType), nil
}
if argVal.IsNull() {
continue
}
if retType == cty.String && argVal.RawEquals(cty.StringVal("")) {
continue
}
return argVal, nil
}
return cty.NilVal, errors.New("no non-null, non-empty-string arguments")
},
})
// IndexFunc constructs a function that finds the element index for a given value in a list.
var IndexFunc = function.New(&function.Spec{
Params: []function.Parameter{
{
Name: "list",
Type: cty.DynamicPseudoType,
},
{
Name: "value",
Type: cty.DynamicPseudoType,
},
},
Type: function.StaticReturnType(cty.Number),
Impl: func(args []cty.Value, retType cty.Type) (ret cty.Value, err error) {
if !(args[0].Type().IsListType() || args[0].Type().IsTupleType()) {
return cty.NilVal, errors.New("argument must be a list or tuple")
}
if !args[0].IsKnown() {
return cty.UnknownVal(cty.Number), nil
}
if args[0].LengthInt() == 0 { // Easy path
return cty.NilVal, errors.New("cannot search an empty list")
}
for it := args[0].ElementIterator(); it.Next(); {
i, v := it.Element()
eq, err := stdlib.Equal(v, args[1])
if err != nil {
return cty.NilVal, err
}
if !eq.IsKnown() {
return cty.UnknownVal(cty.Number), nil
}
if eq.True() {
return i, nil
}
}
return cty.NilVal, errors.New("item not found")
},
})
// LookupFunc constructs a function that performs dynamic lookups of map types.
var LookupFunc = function.New(&function.Spec{
Params: []function.Parameter{
{
Name: "inputMap",
Type: cty.DynamicPseudoType,
},
{
Name: "key",
Type: cty.String,
},
},
VarParam: &function.Parameter{
Name: "default",
Type: cty.DynamicPseudoType,
AllowUnknown: true,
AllowDynamicType: true,
AllowNull: true,
},
Type: func(args []cty.Value) (ret cty.Type, err error) {
if len(args) < 1 || len(args) > 3 {
return cty.NilType, fmt.Errorf("lookup() takes two or three arguments, got %d", len(args))
}
ty := args[0].Type()
switch {
case ty.IsObjectType():
if !args[1].IsKnown() {
return cty.DynamicPseudoType, nil
}
key := args[1].AsString()
if ty.HasAttribute(key) {
return args[0].GetAttr(key).Type(), nil
} else if len(args) == 3 {
// if the key isn't found but a default is provided,
// return the default type
return args[2].Type(), nil
}
return cty.DynamicPseudoType, function.NewArgErrorf(0, "the given object has no attribute %q", key)
case ty.IsMapType():
if len(args) == 3 {
_, err = convert.Convert(args[2], ty.ElementType())
if err != nil {
return cty.NilType, function.NewArgErrorf(2, "the default value must have the same type as the map elements")
}
}
return ty.ElementType(), nil
default:
return cty.NilType, function.NewArgErrorf(0, "lookup() requires a map as the first argument")
}
},
Impl: func(args []cty.Value, retType cty.Type) (ret cty.Value, err error) {
var defaultVal cty.Value
defaultValueSet := false
if len(args) == 3 {
defaultVal = args[2]
defaultValueSet = true
}
mapVar := args[0]
lookupKey := args[1].AsString()
if !mapVar.IsKnown() {
return cty.UnknownVal(retType), nil
}
if mapVar.Type().IsObjectType() {
if mapVar.Type().HasAttribute(lookupKey) {
return mapVar.GetAttr(lookupKey), nil
}
} else if mapVar.HasIndex(cty.StringVal(lookupKey)) == cty.True {
return mapVar.Index(cty.StringVal(lookupKey)), nil
}
if defaultValueSet {
defaultVal, err = convert.Convert(defaultVal, retType)
if err != nil {
return cty.NilVal, err
}
return defaultVal, nil
}
return cty.UnknownVal(cty.DynamicPseudoType), fmt.Errorf(
"lookup failed to find '%s'", lookupKey)
},
})
// MatchkeysFunc constructs a function that constructs a new list by taking a
// subset of elements from one list whose indexes match the corresponding
// indexes of values in another list.
var MatchkeysFunc = function.New(&function.Spec{
Params: []function.Parameter{
{
Name: "values",
Type: cty.List(cty.DynamicPseudoType),
},
{
Name: "keys",
Type: cty.List(cty.DynamicPseudoType),
},
{
Name: "searchset",
Type: cty.List(cty.DynamicPseudoType),
},
},
Type: func(args []cty.Value) (cty.Type, error) {
ty, _ := convert.UnifyUnsafe([]cty.Type{args[1].Type(), args[2].Type()})
if ty == cty.NilType {
return cty.NilType, errors.New("keys and searchset must be of the same type")
}
// the return type is based on args[0] (values)
return args[0].Type(), nil
},
Impl: func(args []cty.Value, retType cty.Type) (ret cty.Value, err error) {
if !args[0].IsKnown() {
return cty.UnknownVal(cty.List(retType.ElementType())), nil
}
if args[0].LengthInt() != args[1].LengthInt() {
return cty.ListValEmpty(retType.ElementType()), errors.New("length of keys and values should be equal")
}
output := make([]cty.Value, 0)
values := args[0]
// Keys and searchset must be the same type.
// We can skip error checking here because we've already verified that
// they can be unified in the Type function
ty, _ := convert.UnifyUnsafe([]cty.Type{args[1].Type(), args[2].Type()})
keys, _ := convert.Convert(args[1], ty)
searchset, _ := convert.Convert(args[2], ty)
// if searchset is empty, return an empty list.
if searchset.LengthInt() == 0 {
return cty.ListValEmpty(retType.ElementType()), nil
}
if !values.IsWhollyKnown() || !keys.IsWhollyKnown() {
return cty.UnknownVal(retType), nil
}
i := 0
for it := keys.ElementIterator(); it.Next(); {
_, key := it.Element()
for iter := searchset.ElementIterator(); iter.Next(); {
_, search := iter.Element()
eq, err := stdlib.Equal(key, search)
if err != nil {
return cty.NilVal, err
}
if !eq.IsKnown() {
return cty.ListValEmpty(retType.ElementType()), nil
}
if eq.True() {
v := values.Index(cty.NumberIntVal(int64(i)))
output = append(output, v)
break
}
}
i++
}
// if we haven't matched any key, then output is an empty list.
if len(output) == 0 {
return cty.ListValEmpty(retType.ElementType()), nil
}
return cty.ListVal(output), nil
},
})
// OneFunc returns either the first element of a one-element list, or null
// if given a zero-element list.
var OneFunc = function.New(&function.Spec{
Params: []function.Parameter{
{
Name: "list",
Type: cty.DynamicPseudoType,
},
},
Type: func(args []cty.Value) (cty.Type, error) {
ty := args[0].Type()
switch {
case ty.IsListType() || ty.IsSetType():
return ty.ElementType(), nil
case ty.IsTupleType():
etys := ty.TupleElementTypes()
switch len(etys) {
case 0:
// No specific type information, so we'll ultimately return
// a null value of unknown type.
return cty.DynamicPseudoType, nil
case 1:
return etys[0], nil
}
}
return cty.NilType, function.NewArgErrorf(0, "must be a list, set, or tuple value with either zero or one elements")
},
Impl: func(args []cty.Value, retType cty.Type) (ret cty.Value, err error) {
val := args[0]
ty := val.Type()
// Our parameter spec above doesn't set AllowUnknown or AllowNull,
// so we can assume our top-level collection is both known and non-null
// in here.
switch {
case ty.IsListType() || ty.IsSetType():
lenVal := val.Length()
if !lenVal.IsKnown() {
return cty.UnknownVal(retType), nil
}
var l int
err := gocty.FromCtyValue(lenVal, &l)
if err != nil {
// It would be very strange to get here, because that would
// suggest that the length is either not a number or isn't
// an integer, which would suggest a bug in cty.
return cty.NilVal, fmt.Errorf("invalid collection length: %s", err)
}
switch l {
case 0:
return cty.NullVal(retType), nil
case 1:
var ret cty.Value
// We'll use an iterator here because that works for both lists
// and sets, whereas indexing directly would only work for lists.
// Since we've just checked the length, we should only actually
// run this loop body once.
for it := val.ElementIterator(); it.Next(); {
_, ret = it.Element()
}
return ret, nil
}
case ty.IsTupleType():
etys := ty.TupleElementTypes()
switch len(etys) {
case 0:
return cty.NullVal(retType), nil
case 1:
ret := val.Index(cty.NumberIntVal(0))
return ret, nil
}
}
return cty.NilVal, function.NewArgErrorf(0, "must be a list, set, or tuple value with either zero or one elements")
},
})
// SumFunc constructs a function that returns the sum of all
// numbers provided in a list
var SumFunc = function.New(&function.Spec{
Params: []function.Parameter{
{
Name: "list",
Type: cty.DynamicPseudoType,
},
},
Type: function.StaticReturnType(cty.Number),
Impl: func(args []cty.Value, retType cty.Type) (ret cty.Value, err error) {
if !args[0].CanIterateElements() {
return cty.NilVal, function.NewArgErrorf(0, "cannot sum noniterable")
}
if args[0].LengthInt() == 0 { // Easy path
return cty.NilVal, function.NewArgErrorf(0, "cannot sum an empty list")
}
arg := args[0].AsValueSlice()
ty := args[0].Type()
if !ty.IsListType() && !ty.IsSetType() && !ty.IsTupleType() {
return cty.NilVal, function.NewArgErrorf(0, fmt.Sprintf("argument must be list, set, or tuple. Received %s", ty.FriendlyName()))
}
if !args[0].IsWhollyKnown() {
return cty.UnknownVal(cty.Number), nil
}
// big.Float.Add can panic if the input values are opposing infinities,
// so we must catch that here in order to remain within
// the cty Function abstraction.
defer func() {
if r := recover(); r != nil {
if _, ok := r.(big.ErrNaN); ok {
ret = cty.NilVal
err = fmt.Errorf("can't compute sum of opposing infinities")
} else {
// not a panic we recognize
panic(r)
}
}
}()
s := arg[0]
if s.IsNull() {
return cty.NilVal, function.NewArgErrorf(0, "argument must be list, set, or tuple of number values")
}
for _, v := range arg[1:] {
if v.IsNull() {
return cty.NilVal, function.NewArgErrorf(0, "argument must be list, set, or tuple of number values")
}
v, err = convert.Convert(v, cty.Number)
if err != nil {
return cty.NilVal, function.NewArgErrorf(0, "argument must be list, set, or tuple of number values")
}
s = s.Add(v)
}
return s, nil
},
})
// TransposeFunc constructs a function that takes a map of lists of strings and
// swaps the keys and values to produce a new map of lists of strings.
var TransposeFunc = function.New(&function.Spec{
Params: []function.Parameter{
{
Name: "values",
Type: cty.Map(cty.List(cty.String)),
},
},
Type: function.StaticReturnType(cty.Map(cty.List(cty.String))),
Impl: func(args []cty.Value, retType cty.Type) (ret cty.Value, err error) {
inputMap := args[0]
if !inputMap.IsWhollyKnown() {
return cty.UnknownVal(retType), nil
}
outputMap := make(map[string]cty.Value)
tmpMap := make(map[string][]string)
for it := inputMap.ElementIterator(); it.Next(); {
inKey, inVal := it.Element()
for iter := inVal.ElementIterator(); iter.Next(); {
_, val := iter.Element()
if !val.Type().Equals(cty.String) {
return cty.MapValEmpty(cty.List(cty.String)), errors.New("input must be a map of lists of strings")
}
outKey := val.AsString()
if _, ok := tmpMap[outKey]; !ok {
tmpMap[outKey] = make([]string, 0)
}
outVal := tmpMap[outKey]
outVal = append(outVal, inKey.AsString())
sort.Strings(outVal)
tmpMap[outKey] = outVal
}
}
for outKey, outVal := range tmpMap {
values := make([]cty.Value, 0)
for _, v := range outVal {
values = append(values, cty.StringVal(v))
}
outputMap[outKey] = cty.ListVal(values)
}
if len(outputMap) == 0 {
return cty.MapValEmpty(cty.List(cty.String)), nil
}
return cty.MapVal(outputMap), nil
},
})
// ListFunc constructs a function that takes an arbitrary number of arguments
// and returns a list containing those values in the same order.
//
// This function is deprecated in Terraform v0.12
var ListFunc = function.New(&function.Spec{
Params: []function.Parameter{},
VarParam: &function.Parameter{
Name: "vals",
Type: cty.DynamicPseudoType,
AllowUnknown: true,
AllowDynamicType: true,
AllowNull: true,
},
Type: func(args []cty.Value) (ret cty.Type, err error) {
return cty.DynamicPseudoType, fmt.Errorf("the \"list\" function was deprecated in Terraform v0.12 and is no longer available; use tolist([ ... ]) syntax to write a literal list")
},
Impl: func(args []cty.Value, retType cty.Type) (ret cty.Value, err error) {
return cty.DynamicVal, fmt.Errorf("the \"list\" function was deprecated in Terraform v0.12 and is no longer available; use tolist([ ... ]) syntax to write a literal list")
},
})
// MapFunc constructs a function that takes an even number of arguments and
// returns a map whose elements are constructed from consecutive pairs of arguments.
//
// This function is deprecated in Terraform v0.12
var MapFunc = function.New(&function.Spec{
Params: []function.Parameter{},
VarParam: &function.Parameter{
Name: "vals",
Type: cty.DynamicPseudoType,
AllowUnknown: true,
AllowDynamicType: true,
AllowNull: true,
},
Type: func(args []cty.Value) (ret cty.Type, err error) {
return cty.DynamicPseudoType, fmt.Errorf("the \"map\" function was deprecated in Terraform v0.12 and is no longer available; use tomap({ ... }) syntax to write a literal map")
},
Impl: func(args []cty.Value, retType cty.Type) (ret cty.Value, err error) {
return cty.DynamicVal, fmt.Errorf("the \"map\" function was deprecated in Terraform v0.12 and is no longer available; use tomap({ ... }) syntax to write a literal map")
},
})
// Length returns the number of elements in the given collection or number of
// Unicode characters in the given string.
func Length(collection cty.Value) (cty.Value, error) {
return LengthFunc.Call([]cty.Value{collection})
}
// AllTrue returns true if all elements of the list are true. If the list is empty,
// return true.
func AllTrue(collection cty.Value) (cty.Value, error) {
return AllTrueFunc.Call([]cty.Value{collection})
}
// AnyTrue returns true if any element of the list is true. If the list is empty,
// return false.
func AnyTrue(collection cty.Value) (cty.Value, error) {
return AnyTrueFunc.Call([]cty.Value{collection})
}
// Coalesce takes any number of arguments and returns the first one that isn't empty.
func Coalesce(args ...cty.Value) (cty.Value, error) {
return CoalesceFunc.Call(args)
}
// Index finds the element index for a given value in a list.
func Index(list, value cty.Value) (cty.Value, error) {
return IndexFunc.Call([]cty.Value{list, value})
}
// List takes any number of list arguments and returns a list containing those
// values in the same order.
func List(args ...cty.Value) (cty.Value, error) {
return ListFunc.Call(args)
}
// Lookup performs a dynamic lookup into a map.
// There are two required arguments, map and key, plus an optional default,
// which is a value to return if no key is found in map.
func Lookup(args ...cty.Value) (cty.Value, error) {
return LookupFunc.Call(args)
}
// Map takes an even number of arguments and returns a map whose elements are constructed
// from consecutive pairs of arguments.
func Map(args ...cty.Value) (cty.Value, error) {
return MapFunc.Call(args)
}
// Matchkeys constructs a new list by taking a subset of elements from one list
// whose indexes match the corresponding indexes of values in another list.
func Matchkeys(values, keys, searchset cty.Value) (cty.Value, error) {
return MatchkeysFunc.Call([]cty.Value{values, keys, searchset})
}
// One returns either the first element of a one-element list, or null
// if given a zero-element list..
func One(list cty.Value) (cty.Value, error) {
return OneFunc.Call([]cty.Value{list})
}
// Sum adds numbers in a list, set, or tuple
func Sum(list cty.Value) (cty.Value, error) {
return SumFunc.Call([]cty.Value{list})
}
// Transpose takes a map of lists of strings and swaps the keys and values to
// produce a new map of lists of strings.
func Transpose(values cty.Value) (cty.Value, error) {
return TransposeFunc.Call([]cty.Value{values})
}