feat: add generate_*.inherit attribute.

Signed-off-by: Tiago Natel <t.nateldemoura@gmail.com>

Author: i4ki

CHANGELOG.md

@@ -24,6 +24,8 @@ Given a version number `MAJOR.MINOR.PATCH`, we increment the:
 
 ### Added
 
+- Add `generate_*.inherit` attribute for controlling if generate blocks must be inherited
+  into child stacks.
 - Add `terramate cloud login --github` for authenticating with the Github account.
 - Add experimental support for `tmgen` file extension for easy code generation/templating
   of existing infrastructure. You can enable it with `terramate.config.experimental = ["tmgen"]`.

cmd/terramate/e2etests/core/generate_test.go

@@ -475,6 +475,60 @@ func TestGenerateWarnsForTmGenNonInheritable(t *testing.T) {
 	})
 }
 
+func TestGenerateFileNonInheritableOutsideStackGeneratesWarning(t *testing.T) {
+	t.Parallel()
+
+	s := sandbox.NoGit(t, true)
+	s.BuildTree([]string{
+		"d:non-stack",
+	})
+
+	s.RootEntry().
+		CreateDir("non-stack").
+		CreateFile(
+			config.DefaultFilename,
+			GenerateFile(
+				Labels("test.txt"),
+				Bool("inherit", false),
+				Str("content", "test"),
+			).String(),
+		)
+
+	tmcli := NewCLI(t, s.RootDir())
+	AssertRunResult(t, tmcli.Run("generate"), RunExpected{
+		Stdout:      "Nothing to do, generated code is up to date\n",
+		StderrRegex: "Warning: non-inheritable generate found outside a stack",
+	})
+}
+
+func TestGenerateHCLNonInheritableOutsideStackGeneratesWarning(t *testing.T) {
+	t.Parallel()
+
+	s := sandbox.NoGit(t, true)
+	s.BuildTree([]string{
+		"d:non-stack",
+	})
+
+	s.RootEntry().
+		CreateDir("non-stack").
+		CreateFile(
+			config.DefaultFilename,
+			GenerateHCL(
+				Labels("test.txt"),
+				Bool("inherit", false),
+				Content(
+					Str("hello", "world"),
+				),
+			).String(),
+		)
+
+	tmcli := NewCLI(t, s.RootDir())
+	AssertRunResult(t, tmcli.Run("generate"), RunExpected{
+		Stdout:      "Nothing to do, generated code is up to date\n",
+		StderrRegex: "Warning: non-inheritable generate found outside a stack",
+	})
+}
+
 type str string
 
 func (s str) String() string {

config/config.go

@@ -508,10 +508,22 @@ func processTmGenFiles(root *Root, cfg *hcl.Config, cfgdir string, dirEntries []
 			Type: "content",
 			Body: body,
 		}
+
+		// should never fail
+		inheritFalse, diags := hclsyntax.ParseExpression([]byte("false"), "<implicit block>", hhcl.InitialPos)
+		if diags.HasErrors() {
+			panic(errors.E(errors.ErrInternal, diags))
+		}
+
+		inheritAttr := &hclsyntax.Attribute{
+			Name: "inherit",
+			Expr: inheritFalse,
+		}
+
 		implicitGenBlock := hcl.GenHCLBlock{
 			IsImplicitBlock: true,
 			Dir:             project.PrjAbsPath(root.HostDir(), cfgdir),
-			NonInheritable:  true,
+			Inherit:         inheritAttr,
 			Range: info.NewRange(root.HostDir(), hhcl.Range{
 				Filename: absFname,
 				Start:    hhcl.InitialPos,