Initial version

terraform-ast.go

@@ -0,0 +1,147 @@
+package main
+
+import (
+	"encoding/json"
+	"flag"
+	"io/ioutil"
+	"os"
+	"strings"
+
+	"fmt"
+
+	"github.com/hashicorp/hcl"
+	"github.com/hashicorp/hcl/hcl/ast"
+	"github.com/hashicorp/hcl/hcl/token"
+)
+
+type VariableDeclaration struct {
+	Name     string
+	Location token.Pos
+}
+
+type ResourceDeclaration struct {
+	Type     string
+	Name     string
+	Location token.Pos
+}
+
+type OutputDeclaration struct {
+	Name     string
+	Location token.Pos
+}
+
+type AstDump struct {
+	Variables []VariableDeclaration
+	Resources []ResourceDeclaration
+	Outputs   []OutputDeclaration
+	RawAst    *ast.File
+}
+
+func GetText(t token.Token) string {
+	return strings.Trim(t.Text, "\"")
+}
+
+func GetPos(t token.Token, path string) token.Pos {
+	location := t.Pos
+	location.Filename = path
+	return location
+}
+
+func CollectDump(astFile *ast.File, path string) (*AstDump, error) {
+	dump := new(AstDump)
+	dump.Variables = []VariableDeclaration{}
+	dump.Resources = []ResourceDeclaration{}
+	dump.Outputs = []OutputDeclaration{}
+	dump.RawAst = astFile
+
+	objectList, ok := astFile.Node.(*ast.ObjectList)
+	if !ok {
+		return nil, fmt.Errorf("Root node is not an objectList %v", astFile.Node)
+	}
+
+	for _, item := range objectList.Items {
+		firstToken := item.Keys[0].Token
+		if firstToken.Type != 4 {
+			continue
+		}
+
+		switch firstToken.Text {
+		case "variable":
+			{
+				variable := VariableDeclaration{
+					Name:     GetText(item.Keys[1].Token),
+					Location: GetPos(item.Keys[1].Token, path),
+				}
+				dump.Variables = append(dump.Variables, variable)
+				break
+			}
+
+		case "resource":
+			{
+				resource := ResourceDeclaration{
+					Name:     GetText(item.Keys[2].Token),
+					Type:     GetText(item.Keys[1].Token),
+					Location: GetPos(item.Keys[2].Token, path), // return position of name
+				}
+				dump.Resources = append(dump.Resources, resource)
+				break
+			}
+
+		case "output":
+			{
+				output := OutputDeclaration{
+					Name:     GetText(item.Keys[1].Token),
+					Location: GetPos(item.Keys[1].Token, path),
+				}
+				dump.Outputs = append(dump.Outputs, output)
+				break
+			}
+		}
+	}
+
+	return dump, nil
+}
+
+func Contents(path string) ([]byte, error) {
+	if path == "-" {
+		return ioutil.ReadAll(os.Stdin)
+	}
+
+	return ioutil.ReadFile(path)
+}
+
+func main() {
+	includeRaw := flag.Bool("raw-ast", false, "include the raw ast")
+	path := flag.String("file", "-", "file to parse")
+
+	flag.Parse()
+
+	source, err := Contents(*path)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "ERROR: Cannot open path '%s'\n", *path)
+		os.Exit(1)
+	}
+
+	astFile, err := hcl.ParseBytes(source)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "ERROR: Cannot parse '%s'\n", err)
+		os.Exit(2)
+	}
+
+	dump, err := CollectDump(astFile, *path)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "ERROR: Could not collect dump '%s'\n", err)
+		os.Exit(3)
+	}
+
+	if !*includeRaw {
+		dump.RawAst = nil
+	}
+
+	json, err := json.MarshalIndent(dump, "", "  ")
+	if err != nil {
+		os.Exit(3)
+	}
+
+	os.Stdout.Write(json)
+}