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, AllowMarked: 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() marks := coll.Marks() switch { case collTy == cty.DynamicPseudoType: return cty.UnknownVal(cty.Number).WithMarks(marks), nil case collTy.IsTupleType(): l := len(collTy.TupleElementTypes()) return cty.NumberIntVal(int64(l)).WithMarks(marks), nil case collTy.IsObjectType(): l := len(collTy.AttributeTypes()) return cty.NumberIntVal(int64(l)).WithMarks(marks), 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, AllowMarked: true, }, { Name: "key", Type: cty.String, AllowMarked: true, }, }, VarParam: &function.Parameter{ Name: "default", Type: cty.DynamicPseudoType, AllowUnknown: true, AllowDynamicType: true, AllowNull: true, AllowMarked: 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 } keyVal, _ := args[1].Unmark() key := keyVal.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 { // intentionally leave default value marked defaultVal = args[2] defaultValueSet = true } // keep track of marks from the collection and key var markses []cty.ValueMarks // unmark collection, retain marks to reapply later mapVar, mapMarks := args[0].Unmark() markses = append(markses, mapMarks) // include marks on the key in the result keyVal, keyMarks := args[1].Unmark() if len(keyMarks) > 0 { markses = append(markses, keyMarks) } lookupKey := keyVal.AsString() if !mapVar.IsKnown() { return cty.UnknownVal(retType).WithMarks(markses...), nil } if mapVar.Type().IsObjectType() { if mapVar.Type().HasAttribute(lookupKey) { return mapVar.GetAttr(lookupKey).WithMarks(markses...), nil } } else if mapVar.HasIndex(cty.StringVal(lookupKey)) == cty.True { return mapVar.Index(cty.StringVal(lookupKey)).WithMarks(markses...), nil } if defaultValueSet { defaultVal, err = convert.Convert(defaultVal, retType) if err != nil { return cty.NilVal, err } return defaultVal.WithMarks(markses...), nil } return cty.UnknownVal(cty.DynamicPseudoType), fmt.Errorf( "lookup failed to find key %s", redactIfSensitive(lookupKey, keyMarks)) }, }) // 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}) }