Add JSON format to list command

CHANGELOG.md

@@ -39,6 +39,10 @@ Given a version number `MAJOR.MINOR.PATCH`, we increment the:
 
 - Fix `terramate cloud login --github` when the Github email is not verified but the associated Firebase account is verified.
 
+### Added
+
+- Add `--format` option to `terramate list --run-order` command. This option allows to format the output of the command as either `json` or `text` (current default). The json format is useful for automation and scripting as it groups the stacks by run order level.
+
 ## v0.12.0
 
 ### Added

commands/stack/list/list.go

@@ -6,6 +6,7 @@ package list
 
 import (
 	"context"
+	"encoding/json"
 	"fmt"
 
 	"github.com/terramate-io/terramate/cloud/api/status"
@@ -28,6 +29,7 @@ type Spec struct {
 	Tags          []string
 	NoTags        []string
 	Printers      printer.Printers
+	Format        string
 }
 
 // StatusFilters contains the status filters for the list command.
@@ -96,8 +98,56 @@ func (s *Spec) printStacksList(allStacks []stack.Entry) error {
 		if err != nil {
 			return errors.E(err, "Invalid stack configuration: "+failReason)
 		}
+
+		if s.Format == "json" {
+			graph, reason, err := run.BuildDAGFromStacks(s.Engine.Config(), stacks,
+				func(s *config.SortableStack) *config.Stack { return s.Stack })
+			if err != nil {
+				return errors.E("Failed to build dependency graph: "+reason)
+			}
+
+			// Calculate levels based on DAG
+			levelGroups := make(map[int][]string)
+			stackLevels := make(map[string]int)
+
+			// Process nodes in topological order
+			order := graph.Order()
+			for _, id := range order {
+				stack, err := graph.Node(id)
+				if err != nil {
+					return errors.E("Failed to access node in graph: "+err.Error())
+				}
+
+				level := 1 // Default level
+				// Check ancestors (dependencies)
+				for _, ancestorID := range graph.AncestorsOf(id) {
+					ancestorLevel := stackLevels[string(ancestorID)]
+					if ancestorLevel >= level {
+						level = ancestorLevel + 1
+					}
+				}
+
+				dir := stack.Stack.Dir.String()
+				stackLevels[dir] = level
+
+				friendlyDir, ok := s.Engine.FriendlyFmtDir(dir)
+				if !ok {
+					printer.Stderr.Error(fmt.Sprintf("Unable to format stack dir %s", dir))
+					continue
+				}
+				levelGroups[level] = append(levelGroups[level], friendlyDir)
+			}
+
+			jsonOutput, err := json.MarshalIndent(levelGroups, "", "  ")
+			if err != nil {
+				return errors.E("Error formatting stack groups as JSON: "+err.Error())
+			}
+			printer.Stdout.Println(string(jsonOutput))
+			return nil
+		}
 	}
 
+	// Original output format for non-runOrder case or when format is not json
 	for _, st := range stacks {
 		dir := st.Dir().String()
 		friendlyDir, ok := s.Engine.FriendlyFmtDir(dir)

ui/tui/cli_handler.go

@@ -319,6 +319,7 @@ func DefaultAfterConfigHandler(ctx context.Context, c *CLI) (commands.Executor,
 			tel.StringFlag("filter-deployment-status", parsedArgs.List.DeploymentStatus),
 			tel.StringFlag("filter-target", parsedArgs.List.Target),
 			tel.BoolFlag("run-order", parsedArgs.List.RunOrder),
+			tel.StringFlag("format", parsedArgs.List.Format),
 		)
 		expStatus := parsedArgs.List.ExperimentalStatus
 		cloudStatus := parsedArgs.List.Status
@@ -354,6 +355,7 @@ func DefaultAfterConfigHandler(ctx context.Context, c *CLI) (commands.Executor,
 			RunOrder: parsedArgs.List.RunOrder,
 			Tags:     parsedArgs.Tags,
 			NoTags:   parsedArgs.NoTags,
+			Format:   parsedArgs.List.Format,
 		}, true, false, nil
 
 	case "generate":

ui/tui/cli_spec.go

@@ -52,6 +52,7 @@ type FlagSpec struct {
 		cloudFilterFlags
 		Target   string `help:"Select the deployment target of the filtered stacks."`
 		RunOrder bool   `default:"false" help:"Sort listed stacks by order of execution"`
+		Format   string `default:"text" help:"Format the output" enum:"text,json"`
 
 		changeDetectionFlags
 	} `cmd:"" help:"List stacks."`