rename_resources.go

package main

import (
	"fmt"
	"io/ioutil"
	"log"
	"regexp"
	"strings"

	gohcl2 "github.com/hashicorp/hcl/v2/gohcl"
	hcl2parse "github.com/hashicorp/hcl/v2/hclparse"
	hcl2write "github.com/hashicorp/hcl/v2/hclwrite"
	"github.com/zclconf/go-cty/cty"
)

type topLevel struct {
	Resources []resource `hcl:"resource,block"`
}

type resource struct {
	Type   string            `hcl:"type,label"`
	Name   string            `hcl:"name,label"`
	Config map[string]string `hcl:",remain"`
}

func main() {
	parser := hcl2parse.NewParser()
	p, parseDiags := parser.ParseHCLFile("project_iam_member.tf")
	if parseDiags.HasErrors() {
		log.Fatal(parseDiags.Error())
	}

	var raw topLevel
	decodeDiags := gohcl2.DecodeBody(p.Body, nil, &raw)
	if decodeDiags.HasErrors() {
		log.Fatal(decodeDiags.Error())
	}

	w := hcl2write.NewFile()
	rootBody := w.Body()

	for _, r := range raw.Resources {
		member := r.Config["member"]
		member = strings.Replace(member, "serviceAccount:", "sa_", 1)
		member = strings.Replace(member, "group:", "", 1)
		member = strings.Replace(member, "user:", "", 1)
		re := regexp.MustCompile("@.+$")
		member = re.ReplaceAllString(member, "")

		role := r.Config["role"]
		role = strings.Replace(role, "projects/xxxxxx/roles/", "", 1)
		role = strings.Replace(role, "roles/", "", 1)

		r.Name = fmt.Sprintf("%s_%s", member, role)
		r.Name = strings.Replace(r.Name, ".", "_", -1)

		resourceBlock := rootBody.AppendNewBlock("resource", []string{r.Type, r.Name})
		resourceBody := resourceBlock.Body()
		for k, v := range r.Config {
			resourceBody.SetAttributeValue(k, cty.StringVal(v))
		}
		rootBody.AppendNewline()
	}

	err := ioutil.WriteFile("./out.tf", w.Bytes(), 0644)
	if err != nil {
		log.Fatal(err)
	}
}