[Experiment] provider: support core build tag

.gitignore

@@ -31,7 +31,7 @@ package-lock.json
 package.json
 skaff/skaff
 sweeper-bin
-terraform-provider-aws
+terraform-provider-aws*
 terraform-providers-schema/
 terraform.tfplan
 terraform.tfstate

internal/generate/awsclient/file.gtpl

@@ -2,6 +2,9 @@
 // SPDX-License-Identifier: MPL-2.0
 
 // Code generated by internal/generate/awsclient/main.go; DO NOT EDIT.
+
+//go:build {{ .BuildTags }}
+
 package conns
 
 import (

internal/generate/awsclient/main.go

@@ -9,6 +9,7 @@ import (
 	"cmp"
 	_ "embed"
 	"slices"
+	"strings"
 
 	"github.com/hashicorp/terraform-provider-aws/internal/generate/common"
 	"github.com/hashicorp/terraform-provider-aws/names/data"
@@ -20,7 +21,8 @@ type ServiceDatum struct {
 }
 
 type TemplateData struct {
-	Services []ServiceDatum
+	BuildTags string
+	Services  []ServiceDatum
 }
 
 func main() {
@@ -36,7 +38,13 @@ func main() {
 		g.Fatalf("error reading service data: %s", err)
 	}
 
-	td := TemplateData{}
+	td := TemplateData{
+		BuildTags: "!core",
+	}
+
+	coreTd := TemplateData{
+		BuildTags: "core",
+	}
 
 	for _, l := range data {
 		if l.Exclude() {
@@ -57,6 +65,10 @@ func main() {
 		}
 
 		td.Services = append(td.Services, s)
+
+		if common.IsCoreService(l.ProviderPackage()) {
+			coreTd.Services = append(coreTd.Services, s)
+		}
 	}
 
 	slices.SortStableFunc(td.Services, func(a, b ServiceDatum) int {
@@ -72,6 +84,21 @@ func main() {
 	if err := d.Write(); err != nil {
 		g.Fatalf("generating file (%s): %s", filename, err)
 	}
+
+	slices.SortStableFunc(coreTd.Services, func(a, b ServiceDatum) int {
+		return cmp.Compare(a.ProviderNameUpper, b.ProviderNameUpper)
+	})
+
+	coreFilename := strings.ReplaceAll(filename, `_gen`, `_core_gen`)
+	coreD := g.NewGoFileDestination(coreFilename)
+
+	if err := coreD.BufferTemplate("awsclient", tmpl, coreTd); err != nil {
+		g.Fatalf("generating file (%s): %s", coreFilename, err)
+	}
+
+	if err := coreD.Write(); err != nil {
+		g.Fatalf("generating file (%s): %s", coreFilename, err)
+	}
 }
 
 //go:embed file.gtpl

internal/generate/common/core_services.go

@@ -0,0 +1,37 @@
+// Copyright IBM Corp. 2014, 2026
+// SPDX-License-Identifier: MPL-2.0
+
+package common
+
+import "slices"
+
+// coreServices is the list of AWS services included when the provider is built
+// with the 'core' tag
+//
+// It includes primary services and their explicitly required dependencies.
+var coreServices = []string{
+	"account",
+	"cloudwatch",
+	"dynamodb",
+	"ec2",
+	"ecs",
+	"eks",
+	"elasticache",
+	"iam",
+	"kms",
+	"lambda",
+	"logs",
+	"organizations",
+	"rds",
+	"s3",
+	"s3control",
+	"sns",
+	"sqs",
+	"sts",
+}
+
+// IsCoreService returns true if the given service package name is considered a
+// core service
+func IsCoreService(name string) bool {
+	return slices.Contains(coreServices, name)
+}

internal/generate/servicepackages/file.tmpl

@@ -3,6 +3,8 @@
 
 // Code generated by internal/generate/servicepackages/main.go; DO NOT EDIT.
 
+//go:build {{ .BuildTags }}
+
 package {{ .PackageName }}
 
 import (

internal/generate/servicepackages/main.go

@@ -12,6 +12,7 @@ import (
 	"fmt"
 	"os"
 	"slices"
+	"strings"
 
 	"github.com/hashicorp/terraform-provider-aws/internal/generate/common"
 	"github.com/hashicorp/terraform-provider-aws/names/data"
@@ -44,6 +45,12 @@ func main() {
 
 	td := TemplateData{
 		PackageName: packageName,
+		BuildTags:   "!core",
+	}
+
+	coreTd := TemplateData{
+		PackageName: packageName,
+		BuildTags:   "core",
 	}
 
 	for _, l := range data {
@@ -61,6 +68,10 @@ func main() {
 		}
 
 		td.Services = append(td.Services, s)
+
+		if common.IsCoreService(p) {
+			coreTd.Services = append(coreTd.Services, s)
+		}
 	}
 
 	slices.SortStableFunc(td.Services, func(a, b ServiceDatum) int {
@@ -76,6 +87,21 @@ func main() {
 	if err := d.Write(); err != nil {
 		g.Fatalf("generating file (%s): %s", filename, err)
 	}
+
+	slices.SortStableFunc(coreTd.Services, func(a, b ServiceDatum) int {
+		return cmp.Compare(a.ProviderPackage, b.ProviderPackage)
+	})
+
+	coreFilename := strings.ReplaceAll(filename, `_gen`, `_core_gen`)
+	coreD := g.NewGoFileDestination(coreFilename)
+
+	if err := coreD.BufferTemplate("servicepackages", tmpl, coreTd); err != nil {
+		g.Fatalf("error generating core service packages list: %s", err)
+	}
+
+	if err := coreD.Write(); err != nil {
+		g.Fatalf("generating file (%s): %s", coreFilename, err)
+	}
 }
 
 type ServiceDatum struct {
@@ -84,6 +110,7 @@ type ServiceDatum struct {
 
 type TemplateData struct {
 	PackageName string
+	BuildTags   string
 	Services    []ServiceDatum
 }