Example of parsing part of nomad's job hcl file.

nomad-job-parsing.go

package main

import (
	"fmt"

	hcl "github.com/hashicorp/hcl/v2"
	"github.com/hashicorp/hcl/v2/hclsimple"
	//"github.com/zclconf/go-cty/cty"
)

type NomadJob struct {
	Name string
	Text string
}

func (j *NomadJob) GetImages() []string {
	var data struct {
		Job struct {
			Name   string   `hcl:"job-name,label"`
			Other  hcl.Body `hcl:"other,remain"`
			Groups []struct {
				Name  string   `hcl:"group-name,label"`
				Other hcl.Body `hcl:"other,remain"`
				Tasks []struct {
					Name   string   `hcl:"task-name,label"`
					Other  hcl.Body `hcl:"other,remain"`
					Config struct {
						Image hcl.Expression `hcl:"image,attr"`
						Other hcl.Body       `hcl:"other,remain"`
					} `hcl:"config,block"`
				} `hcl:"task,block"`
			} `hcl:"group,block"`
		} `hcl:"job,block"`
	}

	fmt.Println(j.Text)
	err := hclsimple.Decode("test.hcl", []byte(j.Text), nil, &data)
	if err != nil {
		panic(err)
	}

	fmt.Printf("=====> %v\n", data.Job.Name)
	for _, group := range data.Job.Groups {
		for _, task := range group.Tasks {
			//ctx := &hcl.EvalContext{
			//	Variables: map[string]cty.Value{
			//		"NOMAD_META_VERSION": cty.StringVal("latest"),
			//	},
			//}

			//value, errs := task.Config.Image.Value(ctx)
			//if errs != nil {
			//	panic(errs)
			//}

			//fmt.Printf("group %v  task %v ----> %v \n", group.Name, task.Name, value.AsString())

			rg := task.Config.Image.Range()
			fmt.Printf("group %v  task %v ----> %v \n", group.Name, task.Name, string(rg.SliceBytes([]byte(j.Text))))

		}
	}

	return nil
}