feat: add stack.id (#441)

generate/genfile/genfile_test.go

@@ -133,7 +133,7 @@ func TestLoadGenerateFiles(t *testing.T) {
 			},
 		},
 		{
-			name:  "all metadata available",
+			name:  "all metadata available by default",
 			stack: "/stack",
 			configs: []hclconfig{
 				{
@@ -146,6 +146,7 @@ stack_path_abs=${terramate.stack.path.absolute}
 stack_path_rel=${terramate.stack.path.relative}
 stack_path_to_root=${terramate.stack.path.to_root}
 stack_path_basename=${terramate.stack.path.basename}
+stack_id=${tm_try(terramate.stack.id, "no-id")}
 stack_name=${terramate.stack.name}
 stack_description=${terramate.stack.description}
 EOT`,
@@ -163,8 +164,37 @@ stack_path_abs=/stack
 stack_path_rel=stack
 stack_path_to_root=..
 stack_path_basename=stack
+stack_id=no-id
 stack_name=stack
 stack_description=
+`,
+					},
+				},
+			},
+		},
+		{
+			name:  "stack.id metadata available",
+			stack: "/stack:id=stack-id",
+			configs: []hclconfig{
+				{
+					path: "/stack/test.tm",
+					add: generateFile(
+						labels("test"),
+						expr("content", `<<EOT
+
+stack_id=${terramate.stack.id}
+EOT`,
+						)),
+				},
+			},
+			want: []result{
+				{
+					name:      "test",
+					condition: true,
+					file: genFile{
+						origin: "/stack/test.tm",
+						body: `
+stack_id=stack-id
 `,
 					},
 				},
@@ -812,8 +842,8 @@ stack_description=
 	for _, tcase := range tcases {
 		t.Run(tcase.name, func(t *testing.T) {
 			s := sandbox.New(t)
-			stackEntry := s.CreateStack(tcase.stack)
-			stack := stackEntry.Load()
+			s.BuildTree([]string{"s:" + tcase.stack})
+			stack := s.LoadStacks()[0]
 
 			for _, cfg := range tcase.configs {
 				test.AppendFile(t, s.RootDir(), cfg.path, cfg.add.String())
@@ -825,10 +855,10 @@ stack_description=
 
 			if len(got) != len(tcase.want) {
 				for i, file := range got {
-					t.Logf("got[%d] = %v", i, file)
+					t.Logf("got[%d] = %+v", i, file)
 				}
 				for i, file := range tcase.want {
-					t.Logf("want[%d] = %v", i, file)
+					t.Logf("want[%d] = %+v", i, file)
 				}
 				t.Fatalf("length of got and want mismatch: got %d but want %d",
 					len(got), len(tcase.want))

generate/genhcl/genhcl_test.go

@@ -851,7 +851,7 @@ func TestLoadGeneratedHCL(t *testing.T) {
 			},
 		},
 		{
-			name:  "all metadata available",
+			name:  "all metadata available by default",
 			stack: "/stacks/stack",
 			configs: []hclconfig{
 				{
@@ -860,6 +860,7 @@ func TestLoadGeneratedHCL(t *testing.T) {
 						labels("root"),
 						content(
 							expr("stack_description", "terramate.stack.description"),
+							expr("stack_id", `tm_try(terramate.stack.id, "no-id")`),
 							expr("stack_name", "terramate.stack.name"),
 							expr("stack_path_abs", "terramate.stack.path.absolute"),
 							expr("stack_path_basename", "terramate.stack.path.basename"),
@@ -877,6 +878,7 @@ func TestLoadGeneratedHCL(t *testing.T) {
 						condition: true,
 						body: hcldoc(
 							str("stack_description", ""),
+							str("stack_id", "no-id"),
 							str("stack_name", "stack"),
 							str("stack_path_abs", "/stacks/stack"),
 							str("stack_path_basename", "stack"),
@@ -887,6 +889,33 @@ func TestLoadGeneratedHCL(t *testing.T) {
 				},
 			},
 		},
+		{
+			name:  "stack.id metadata available",
+			stack: "/stacks/stack:id=stack-id",
+			configs: []hclconfig{
+				{
+					path: "/",
+					add: generateHCL(
+						labels("root"),
+						content(
+							expr("stack_id", "terramate.stack.id"),
+						),
+					),
+				},
+			},
+			want: []result{
+				{
+					name: "root",
+					hcl: genHCL{
+						origin:    defaultCfg("/"),
+						condition: true,
+						body: hcldoc(
+							str("stack_id", "stack-id"),
+						),
+					},
+				},
+			},
+		},
 		{
 			name:  "generate HCL on project root dir",
 			stack: "/stacks/stack",
@@ -1460,8 +1489,8 @@ func TestLoadGeneratedHCL(t *testing.T) {
 	for _, tcase := range tcases {
 		t.Run(tcase.name, func(t *testing.T) {
 			s := sandbox.New(t)
-			stackEntry := s.CreateStack(tcase.stack)
-			stack := stackEntry.Load()
+			s.BuildTree([]string{"s:" + tcase.stack})
+			stack := s.LoadStacks()[0]
 
 			for _, cfg := range tcase.configs {
 				filename := cfg.filename

hcl/hcl.go

@@ -17,6 +17,7 @@ package hcl
 import (
 	"os"
 	"path/filepath"
+	"regexp"
 	"sort"
 	"strings"
 
@@ -79,8 +80,16 @@ type Terramate struct {
 	Config *RootConfig
 }
 
+// StackID represents the stack ID. Its zero value represents an undefined ID.
+type StackID struct {
+	id *string
+}
+
 // Stack is the parsed "stack" HCL block.
 type Stack struct {
+	// ID of the stack. If the ID is nil it indicates this stack has no ID.
+	ID StackID
+
 	// Name of the stack
 	Name string
 
@@ -153,6 +162,27 @@ type TerramateParser struct {
 	parsed bool
 }
 
+var stackIDRegex = regexp.MustCompile("^[a-zA-Z0-9_-]{1,64}$")
+
+// NewStackID creates a new StackID with the given string as its id.
+// It guarantees that the id passed is a valid StackID value,
+// an error is returned otherwise.
+func NewStackID(id string) (StackID, error) {
+	if !stackIDRegex.MatchString(id) {
+		return StackID{}, errors.E("Stack ID %q doesn't match %q", id, stackIDRegex)
+	}
+	return StackID{id: &id}, nil
+}
+
+// Value returns the ID string value and true if this StackID is defined,
+// it returns "" and false otherwise.
+func (s StackID) Value() (string, bool) {
+	if s.id == nil {
+		return "", false
+	}
+	return *s.id, true
+}
+
 // parsedFile tells the origin and kind of the parsedFile.
 // The kind can be either internal or external, meaning the file was parsed
 // by this parser or by another parser instance, respectively.
@@ -888,6 +918,23 @@ func parseStack(stack *Stack, stackblock *ast.Block) error {
 			Msg("Setting attribute on configuration.")
 
 		switch attr.Name {
+		case "id":
+			if attrVal.Type() != cty.String {
+				errs.Append(errors.E(attr.NameRange,
+					"field stack.\"id\" must be a \"string\" but is %q",
+					attrVal.Type().FriendlyName()),
+				)
+				continue
+			}
+			id, err := NewStackID(attrVal.AsString())
+			if err != nil {
+				errs.Append(errors.E(attr.NameRange, err))
+				continue
+			}
+			logger.Trace().
+				Str("id", attrVal.AsString()).
+				Msg("found valid stack ID definition")
+			stack.ID = id
 		case "name":
 			if attrVal.Type() != cty.String {
 				errs.Append(errors.E(attr.NameRange,