Merge pull request #11542 from rifelpet/tf-fn

Add support for arbitrary terraform functions

upup/pkg/fi/cloudup/terraform/hcl2.go

@@ -20,6 +20,7 @@ import (
 	"fmt"
 	"reflect"
 	"sort"
+	"strings"
 
 	"github.com/hashicorp/hcl/v2"
 	"github.com/hashicorp/hcl/v2/hclsyntax"
@@ -103,11 +104,11 @@ func writeValue(body *hclwrite.Body, key string, value cty.Value) {
 // key = res_type.res_name.res_prop
 // key = file("${module.path}/foo")
 func writeLiteral(body *hclwrite.Body, key string, literal *terraformWriter.Literal) {
-	if literal.FilePath != "" {
+	if literal.FnName != "" {
 		tokens := hclwrite.Tokens{
 			{
 				Type:  hclsyntax.TokenIdent,
-				Bytes: []byte(fmt.Sprintf("%v(%q)", literal.FileFn, literal.FilePath)),
+				Bytes: []byte(fmt.Sprintf("%v(%v)", literal.FnName, strings.Join(literal.FnArgs, ", "))),
 			},
 		}
 		body.SetAttributeRaw(key, tokens)
@@ -193,8 +194,11 @@ func writeMap(body *hclwrite.Body, key string, values map[string]cty.Value) {
 		if literal, ok := refLiteral.Interface().(*terraformWriter.Literal); err == nil && ok {
 			// For maps of literals we currently only support file references
 			// If we ever need to support a map of strings to resource property references that can be added here
-			if literal.FilePath != "" {
-				tokens = append(tokens, &hclwrite.Token{Type: hclsyntax.TokenIdent, Bytes: []byte(fmt.Sprintf("%v(%q)", literal.FileFn, literal.FilePath))})
+			if literal.FnName != "" {
+				tokens = append(tokens, &hclwrite.Token{
+					Type:  hclsyntax.TokenIdent,
+					Bytes: []byte(fmt.Sprintf("%v(%v)", literal.FnName, strings.Join(literal.FnArgs, ", "))),
+				})
 			} else if literal.Value != "" {
 				tokens = append(tokens, []*hclwrite.Token{
 					{Type: hclsyntax.TokenOQuote, Bytes: []byte{'"'}, SpacesBefore: 1},

upup/pkg/fi/cloudup/terraform/hcl2_test.go

@@ -133,7 +133,7 @@ func TestWriteLiteral(t *testing.T) {
 		},
 		{
 			name:     "file",
-			literal:  terraformWriter.LiteralFileExpression("${path.module}/foo", false),
+			literal:  terraformWriter.LiteralFunctionExpression("file", []string{"\"${path.module}/foo\""}),
 			expected: `foo = file("${path.module}/foo")`,
 		},
 	}
@@ -272,13 +272,15 @@ func TestWriteMapLiterals(t *testing.T) {
 		{
 			name: "literal values",
 			values: map[string]terraformWriter.Literal{
-				"key1": *terraformWriter.LiteralFileExpression("${module.path}/path/to/value1", false),
-				"key2": *terraformWriter.LiteralFileExpression("${module.path}/path/to/value2", true),
+				"key1": *terraformWriter.LiteralFunctionExpression("file", []string{"\"${module.path}/path/to/value1\""}),
+				"key2": *terraformWriter.LiteralFunctionExpression("filebase64", []string{"\"${module.path}/path/to/value2\""}),
+				"key3": *terraformWriter.LiteralFunctionExpression("cidrsubnet", []string{"\"172.16.0.0/12\"", "4", "2"}),
 			},
 			expected: `
 metadata = {
   "key1" = file("${module.path}/path/to/value1")
   "key2" = filebase64("${module.path}/path/to/value2")
+  "key3" = cidrsubnet("172.16.0.0/12", 4, 2)
 }
 			`,
 		},

upup/pkg/fi/cloudup/terraformWriter/literal.go

@@ -20,17 +20,11 @@ import (
 	"encoding/json"
 	"fmt"
 	"sort"
+	"strings"
 
 	"k8s.io/klog/v2"
 )
 
-type fileFn string
-
-const (
-	fileFnFile       fileFn = "file"
-	fileFnFileBase64 fileFn = "filebase64"
-)
-
 // Literal represents a literal in terraform syntax
 type Literal struct {
 	// Value is only used in JSON output via the TerraformJSON feature flag
@@ -43,10 +37,12 @@ type Literal struct {
 	ResourceName string `cty:"resource_name"`
 	// ResourceProp represents the property of a resource in a literal reference
 	ResourceProp string `cty:"resource_prop"`
-	// FilePath represents the path for a file reference
-	FilePath string `cty:"file_path"`
-	// FileFn represents the function used to reference the file
-	FileFn fileFn `cty:"file_fn"`
+
+	// FnName represents the name of a terraform function.
+	FnName string `cty:"fn_name"`
+	// FnArgs contains string representations of arguments to the function call.
+	// Any string arguments must be quoted.
+	FnArgs []string `cty:"fn_arg"`
 }
 
 var _ json.Marshaler = &Literal{}
@@ -55,15 +51,11 @@ func (l *Literal) MarshalJSON() ([]byte, error) {
 	return json.Marshal(&l.Value)
 }
 
-func LiteralFileExpression(modulePath string, base64 bool) *Literal {
-	fn := fileFnFile
-	if base64 {
-		fn = fileFnFileBase64
-	}
+func LiteralFunctionExpression(functionName string, args []string) *Literal {
 	return &Literal{
-		Value:    fmt.Sprintf("${%v(%q)}", fn, modulePath),
-		FilePath: modulePath,
-		FileFn:   fn,
+		Value:  fmt.Sprintf("${%v(%v)}", functionName, strings.Join(args, ", ")),
+		FnName: functionName,
+		FnArgs: args,
 	}
 }
 

upup/pkg/fi/cloudup/terraformWriter/writer.go

@@ -75,9 +75,12 @@ func (t *TerraformWriter) AddFileBytes(resourceType string, resourceName string,
 	p := path.Join("data", id)
 	t.Files[p] = data
 
-	modulePath := path.Join("${path.module}", p)
-	l := LiteralFileExpression(modulePath, base64)
-	return l, nil
+	modulePath := fmt.Sprintf("%q", path.Join("${path.module}", p))
+	fn := "file"
+	if base64 {
+		fn = "filebase64"
+	}
+	return LiteralFunctionExpression(fn, []string{modulePath}), nil
 }
 
 func (t *TerraformWriter) RenderResource(resourceType string, resourceName string, e interface{}) error {