support terragrunt (#76)

Author: Spartakovic

pkg/digger/digger.go

@@ -64,6 +64,7 @@ func RunCommandsPerProject(commandsPerProject []ProjectCommand, repoOwner string
 				projectCommands.ProjectName,
 				projectCommands.ProjectDir,
 				repoName,
+				projectCommands.Terragrunt,
 				prManager,
 				projectLock,
 				diggerConfig,
@@ -104,6 +105,7 @@ type ProjectCommand struct {
 	ProjectName      string
 	ProjectDir       string
 	ProjectWorkspace string
+	Terragrunt       bool
 	Commands         []string
 }
 
@@ -119,20 +121,23 @@ func ConvertGithubEventToCommands(event models.Event, impactedProjects []Project
 					ProjectName:      project.Name,
 					ProjectDir:       project.Dir,
 					ProjectWorkspace: project.Workspace,
+					Terragrunt:       project.Terragrunt,
 					Commands:         project.WorkflowConfiguration.OnCommitToDefault,
 				})
 			} else if event.Action == "opened" || event.Action == "reopened" || event.Action == "synchronize" {
 				commandsPerProject = append(commandsPerProject, ProjectCommand{
 					ProjectName:      project.Name,
 					ProjectDir:       project.Dir,
 					ProjectWorkspace: project.Workspace,
+					Terragrunt:       project.Terragrunt,
 					Commands:         project.WorkflowConfiguration.OnPullRequestPushed,
 				})
 			} else if event.Action == "closed" {
 				commandsPerProject = append(commandsPerProject, ProjectCommand{
 					ProjectName:      project.Name,
 					ProjectDir:       project.Dir,
 					ProjectWorkspace: project.Workspace,
+					Terragrunt:       project.Terragrunt,
 					Commands:         project.WorkflowConfiguration.OnPullRequestClosed,
 				})
 			}
@@ -157,6 +162,7 @@ func ConvertGithubEventToCommands(event models.Event, impactedProjects []Project
 						ProjectName:      project.Name,
 						ProjectDir:       project.Dir,
 						ProjectWorkspace: workspace,
+						Terragrunt:       project.Terragrunt,
 						Commands:         []string{command},
 					})
 				}
@@ -203,6 +209,7 @@ type DiggerExecutor struct {
 	projectName  string
 	projectDir   string
 	repoName     string
+	terragrunt   bool
 	prManager    github.PullRequestManager
 	lock         utils.ProjectLock
 	configDigger *DiggerConfig
@@ -214,7 +221,13 @@ func (d DiggerExecutor) LockId() string {
 
 func (d DiggerExecutor) Plan(prNumber int) {
 
-	terraformExecutor := terraform.Terraform{WorkingDir: path.Join(d.workingDir, d.projectDir), Workspace: d.workspace}
+	var terraformExecutor terraform.TerraformExecutor
+
+	if d.terragrunt {
+		terraformExecutor = terraform.Terragrunt{WorkingDir: path.Join(d.workingDir, d.projectDir)}
+	} else {
+		terraformExecutor = terraform.Terraform{WorkingDir: path.Join(d.workingDir, d.projectDir), Workspace: d.workspace}
+	}
 
 	res, err := d.lock.Lock(d.LockId(), prNumber)
 	if err != nil {
@@ -234,7 +247,14 @@ func (d DiggerExecutor) Plan(prNumber int) {
 }
 
 func (d DiggerExecutor) Apply(prNumber int) {
-	terraformExecutor := terraform.Terraform{WorkingDir: path.Join(d.workingDir, d.projectDir), Workspace: d.workspace}
+	var terraformExecutor terraform.TerraformExecutor
+
+	if d.terragrunt {
+		terraformExecutor = terraform.Terragrunt{WorkingDir: path.Join(d.workingDir, d.projectDir)}
+	} else {
+		terraformExecutor = terraform.Terraform{WorkingDir: path.Join(d.workingDir, d.projectDir), Workspace: d.workspace}
+	}
+
 	if res, _ := d.lock.Lock(d.LockId(), prNumber); res {
 		stdout, stderr, err := terraformExecutor.Apply()
 		applyOutput := cleanupTerraformApply(true, err, stdout, stderr)

pkg/digger/digger_config.go

@@ -25,6 +25,7 @@ type Project struct {
 	Name                  string                `yaml:"name"`
 	Dir                   string                `yaml:"dir"`
 	Workspace             string                `yaml:"workspace"`
+	Terragrunt            bool                  `yaml:"terragrunt"`
 	WorkflowConfiguration WorkflowConfiguration `yaml:"workflow_configuration"`
 }
 
@@ -33,7 +34,8 @@ var ErrDiggerConfigConflict = errors.New("more than one digger config file detec
 func (p *Project) UnmarshalYAML(unmarshal func(interface{}) error) error {
 	type rawProject Project
 	raw := rawProject{
-		Workspace: "default",
+		Workspace:  "default",
+		Terragrunt: false,
 		WorkflowConfiguration: WorkflowConfiguration{
 			OnPullRequestPushed: []string{"digger plan"},
 			OnPullRequestClosed: []string{"digger unlock"},
@@ -73,9 +75,10 @@ func NewDiggerConfig(workingDir string) (*DiggerConfig, error) {
 
 func defaultProject() Project {
 	return Project{
-		Name:      "default",
-		Dir:       ".",
-		Workspace: "default",
+		Name:       "default",
+		Dir:        ".",
+		Workspace:  "default",
+		Terragrunt: false,
 		WorkflowConfiguration: WorkflowConfiguration{
 			OnPullRequestPushed: []string{"digger plan"},
 			OnPullRequestClosed: []string{"digger unlock"},

pkg/terraform/tf.go

@@ -1,24 +1,55 @@
 package terraform
 
 import (
+	"bytes"
 	"context"
 	"fmt"
 	"github.com/hashicorp/terraform-exec/tfexec"
 	"log"
 	"os"
+	"os/exec"
 )
 
 type TerraformExecutor interface {
 	Apply() (string, string, error)
 	Plan() (bool, string, string, error)
 }
 
+type Terragrunt struct {
+	WorkingDir string
+}
+
 type Terraform struct {
 	WorkingDir string
 	Workspace  string
 }
 
-func (terraform *Terraform) Apply() (string, string, error) {
+func (terragrunt Terragrunt) Apply() (string, string, error) {
+	return terragrunt.runTerragruntCommand("apply")
+}
+
+func (terragrunt Terragrunt) Plan() (bool, string, string, error) {
+	stdout, stderr, err := terragrunt.runTerragruntCommand("plan")
+	return true, stdout, stderr, err
+}
+
+func (terragrunt Terragrunt) runTerragruntCommand(command string) (string, string, error) {
+	cmd := exec.Command("terragrunt", command, "--terragrunt-working-dir", terragrunt.WorkingDir)
+
+	var stdout, stderr bytes.Buffer
+	cmd.Stdout = &stdout
+	cmd.Stderr = &stderr
+
+	err := cmd.Run()
+
+	if err != nil {
+		fmt.Println("Error:", err)
+	}
+
+	return stdout.String(), stderr.String(), err
+}
+
+func (terraform Terraform) Apply() (string, string, error) {
 	println("digger apply")
 	execDir := "terraform"
 	tf, err := tfexec.NewTerraform(terraform.WorkingDir, execDir)
@@ -74,7 +105,7 @@ func (sw *StdWriter) GetString() string {
 	return s
 }
 
-func (terraform *Terraform) Plan() (bool, string, string, error) {
+func (terraform Terraform) Plan() (bool, string, string, error) {
 	execDir := "terraform"
 	tf, err := tfexec.NewTerraform(terraform.WorkingDir, execDir)
 

pkg/terraform/utils.go

@@ -101,6 +101,7 @@ projects:
   branch: /main/
   dir: .
   workspace: default
+  terragrunt: false
   workflow_configuration:
     on_pull_request_pushed: [digger plan]
     on_pull_request_closed: [digger unlock]