fix: warn if Terragrunt dependency is outside project.

CHANGELOG.md

@@ -34,6 +34,8 @@ Given a version number `MAJOR.MINOR.PATCH`, we increment the:
 
 - Fix the command-line parsing of `run` and `script run` which were not failing from unknown flags.
 - Fix `create --all-terragrunt` creating Terragrunt stacks with cycles.
+- Panic in the Terragrunt integration when the project had modules with dependency paths outside the current Terramate project.
+  - Now Terramate throw a warning for such configurations.
 
 ## v0.11.3
 

cmd/terramate/cli/cli.go

@@ -1609,7 +1609,7 @@ func (c *cli) initTerragrunt() {
 		for _, otherMod := range mod.After.Strings() {
 			// Parent stack modules must be excluded because of implicit filesystem ordering.
 			// Parent stacks are always executed before child stacks.
-			if mod.Path.HasPrefix(otherMod + "/") {
+			if otherMod == "/" || mod.Path.HasPrefix(otherMod+"/") {
 				continue
 			}
 			// after stacks must not be defined as child stacks

e2etests/core/create_all_terragrunt_test.go

@@ -438,6 +438,68 @@ func TestCreateAllTerragrunt(t *testing.T) {
 				StderrRegex: "Found a dependency cycle between modules",
 			},
 		},
+		{
+			name: "Terragrunt with dependency defined outside of the Terramate project",
+			layout: []string{
+				hclfile("terragrunt.hcl", Doc(
+					Block("terraform",
+						Str("source", "github.com/some/repo"),
+					),
+					Block("dependency",
+						Labels("module2"),
+						Str("config_path", `../other`),
+					),
+					Block("dependencies",
+						Expr("paths", `["../other"]`),
+					))),
+				hclfile("../other/terragrunt.hcl", Doc(
+					Block("terraform",
+						Str("source", "github.com/some/repo"),
+					),
+				)),
+			},
+			want: RunExpected{
+				StderrRegexes: []string{
+					regexp.QuoteMeta("Warning: Dependency outside of Terramate project detected in `dependency.config_path` configuration. Ignoring."),
+					regexp.QuoteMeta("Warning: Dependency outside of Terramate project detected in `dependencies.paths` configuration. Ignoring."),
+				},
+				Stdout: nljoin(
+					"Created stack /",
+				),
+			},
+			wantOrder: []string{"."},
+		},
+		{
+			name: "Terragrunt with dependency defined outside of the Terramate project (sharing same base path)",
+			layout: []string{
+				hclfile("terragrunt.hcl", Doc(
+					Block("terraform",
+						Str("source", "github.com/some/repo"),
+					),
+					Block("dependency",
+						Labels("module2"),
+						Str("config_path", `../sandboxy`),
+					),
+					Block("dependencies",
+						Expr("paths", `["../sandboxy"]`),
+					))),
+				hclfile("../sandboxy/terragrunt.hcl", Doc(
+					Block("terraform",
+						Str("source", "github.com/some/repo"),
+					),
+				)),
+			},
+			want: RunExpected{
+				StderrRegexes: []string{
+					regexp.QuoteMeta("Warning: Dependency outside of Terramate project detected in `dependency.config_path` configuration. Ignoring."),
+					regexp.QuoteMeta("Warning: Dependency outside of Terramate project detected in `dependencies.paths` configuration. Ignoring."),
+				},
+				Stdout: nljoin(
+					"Created stack /",
+				),
+			},
+			wantOrder: []string{"."},
+		},
 	} {
 		tc := tc
 		t.Run(tc.name, func(t *testing.T) {

project/project.go

@@ -122,8 +122,14 @@ func PrjAbsPath(root, abspath string) Path {
 	if !filepath.IsAbs(abspath) {
 		panic(fmt.Errorf("path %q is not absolute", abspath))
 	}
+	if root == abspath {
+		return NewPath("/")
+	}
+	if !strings.HasSuffix(root, string(filepath.Separator)) { // accounts for root=/
+		root = root + string(filepath.Separator)
+	}
 	if !strings.HasPrefix(abspath, root) {
-		panic(fmt.Errorf("abspath %q does not start with root %q", abspath, root))
+		panic(fmt.Errorf(`abspath %q does not start with root %q`, abspath, root))
 	}
 	d := filepath.ToSlash(strings.TrimPrefix(abspath, root))
 	if d == "" {

tg/tg_module.go

@@ -5,11 +5,12 @@ package tg
 
 import (
 	"context"
+	"fmt"
 	"io"
 	"os"
-	"path"
 	"path/filepath"
 	"sort"
+	"strings"
 
 	"github.com/gruntwork-io/go-commons/env"
 	"github.com/gruntwork-io/terragrunt/config"
@@ -18,6 +19,7 @@ import (
 	"github.com/gruntwork-io/terragrunt/util"
 	"github.com/rs/zerolog/log"
 	"github.com/terramate-io/terramate/errors"
+	"github.com/terramate-io/terramate/printer"
 	"github.com/terramate-io/terramate/project"
 	"github.com/zclconf/go-cty/cty/function"
 )
@@ -180,6 +182,11 @@ func ScanModules(rootdir string, dir project.Path, trackDependencies bool) (Modu
 				if !filepath.IsAbs(depPath) {
 					depPath = filepath.Join(tgMod.Path, depPath)
 				}
+				if depPath != rootdir && !strings.HasPrefix(depPath, rootdir+string(filepath.Separator)) {
+					warnDependencyOutsideProject(mod, depPath, "dependency.config_path")
+
+					continue
+				}
 				dependsOn[project.PrjAbsPath(rootdir, depPath)] = struct{}{}
 			}
 		}
@@ -191,14 +198,17 @@ func ScanModules(rootdir string, dir project.Path, trackDependencies bool) (Modu
 		}
 
 		if tgConfig.Dependencies != nil {
-			for _, dep := range tgConfig.Dependencies.Paths {
-				var p project.Path
-				if !path.IsAbs(dep) {
-					p = mod.Path.Join(dep)
-				} else {
-					logger.Debug().Str("dep-path", dep).Msg("ignore absolute path")
+			for _, depPath := range tgConfig.Dependencies.Paths {
+				if !filepath.IsAbs(depPath) {
+					depPath = filepath.Join(tgMod.Path, depPath)
+				}
+				if depPath != rootdir && !strings.HasPrefix(depPath, rootdir+string(filepath.Separator)) {
+					warnDependencyOutsideProject(mod, depPath, "dependencies.paths")
+
 					continue
 				}
+
+				p := project.PrjAbsPath(rootdir, depPath)
 				mod.After = append(mod.After, p)
 			}
 			mod.After.Sort()
@@ -252,3 +262,11 @@ func newTerragruntOptions(dir string) *options.TerragruntOptions {
 
 	return opts
 }
+
+func warnDependencyOutsideProject(mod *Module, dep string, field string) {
+	printer.Stderr.WarnWithDetails(fmt.Sprintf("Dependency outside of Terramate project detected in `%s` configuration. Ignoring.", field),
+		errors.E("The Terragrunt module %s depends on the module at %s, which is located outside of the your current"+
+			" Terramate project. To resolve this ensure the dependent module is part of your Terramate project.",
+			mod.Path, dep),
+	)
+}