backport of commit 1f4f2aebca

test/mini_plugin/datasource/dynamic/data.go

@@ -0,0 +1,66 @@
+// Copyright (c) HashiCorp, Inc.
+// SPDX-License-Identifier: MPL-2.0
+
+//go:generate packer-sdc mapstructure-to-hcl2 -type Config,NestedFirst,NestedSecond,DatasourceOutput
+package dynamic
+
+import (
+	"log"
+
+	"github.com/hashicorp/hcl/v2/hcldec"
+	"github.com/hashicorp/packer-plugin-sdk/hcl2helper"
+	"github.com/hashicorp/packer-plugin-sdk/template/config"
+	"github.com/zclconf/go-cty/cty"
+)
+
+type NestedSecond struct {
+	Name string `mapstructure:"name" required:"true"`
+}
+
+type NestedFirst struct {
+	Name    string         `mapstructure:"name" required:"true"`
+	Nesteds []NestedSecond `mapstructure:"extra" required:"false"`
+}
+
+type Config struct {
+	Nesteds []NestedFirst `mapstructure:"extra" required:"false"`
+}
+
+type Datasource struct {
+	config Config
+}
+
+type DatasourceOutput struct {
+	Status string `mapstructure:"data"`
+}
+
+func (d *Datasource) ConfigSpec() hcldec.ObjectSpec {
+	return d.config.FlatMapstructure().HCL2Spec()
+}
+
+func (d *Datasource) Configure(raws ...interface{}) error {
+	err := config.Decode(&d.config, nil, raws...)
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+func (d *Datasource) OutputSpec() hcldec.ObjectSpec {
+	return (&DatasourceOutput{}).FlatMapstructure().HCL2Spec()
+}
+
+func (d *Datasource) Execute() (cty.Value, error) {
+	log.Printf("[DATASOURCE-DYNAMIC] Executing datasource dynamic")
+	for _, nest := range d.config.Nesteds {
+		log.Printf("[DATASOURCE-DYNAMIC] - First nest: %s", nest.Name)
+		for _, nestedConfig := range nest.Nesteds {
+			log.Printf("[DATASOURCE-DYNAMIC] - Second nest: %s.%s", nest.Name, nestedConfig.Name)
+		}
+	}
+
+	output := DatasourceOutput{
+		Status: "OK",
+	}
+	return hcl2helper.HCL2ValueFromConfig(output, d.OutputSpec()), nil
+}