support conditionally disabling TF plan

This seeks to address issue #142 by adding two fields to `MultiStateMigratorConfig`: * `disable_from_dir_diff_check` - when `true`, `tfmigrator` skips running `terraform plan` in the `from_dir`. Default: `false`. * `disable_from_to_diff_check` - when `true`, `tfmigrator` skips running `terraform plan` in the `to_dir`. Default: `false`. Example: ```hcl migration "multi_state" "test" { from_dir = "." disable_from_dir_diff_check = true to_dir = "dir2" disable_to_dir_diff_check = true actions = [ "mv aws_security_group.baz aws_security_group.baz2", ] } ``` Signed-off-by: Mike Ball <mikedball@gmail.com>
minamijoyo · Aug 4, 2023 · 87dd6ac · 87dd6ac
1 parent 1fb61da
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diff --git a/README.md b/README.md
@@ -638,8 +638,10 @@ migration "state" "test" {
 The `multi_state` migration updates states in two different directories. It is intended for moving resources across states. It has the following attributes.
 
 - `from_dir` (required): A working directory where states of resources move from.
+- `disable_from_dir_diff_check` (optional): If true, `tfmigrate` will not perform and analyze a `terraform plan` in the `from_dir`.
 - `from_workspace` (optional): A terraform workspace in the FROM directory. Defaults to "default".
 - `to_dir` (required): A working directory where states of resources move to.
+- `disable_to_dir_diff_check` (optional): If true, `tfmigrate` will not perform and analyze a `terraform plan` in the `to_dir`.
 - `to_workspace` (optional): A terraform workspace in the TO directory. Defaults to "default".
 - `actions` (required): Actions is a list of multi state action. An action is a plain text for state operation. Valid formats are the following.
   - `"mv <source> <destination>"`

diff --git a/tfmigrate/multi_state_migrator.go b/tfmigrate/multi_state_migrator.go
@@ -13,8 +13,14 @@ import (
 type MultiStateMigratorConfig struct {
 	// FromDir is a working directory where states of resources move from.
 	FromDir string `hcl:"from_dir"`
+	// DisableFromDirDiffCheck controls whether or not to run and analyze Terraform
+	// plan within the from_dir.
+	DisableFromDirDiffCheck bool `hcl:"disable_from_dir_diff_check,optional"`
 	// ToDir is a working directory where states of resources move to.
 	ToDir string `hcl:"to_dir"`
+	// DisableToDirDiffCheck controls whether or not to and analyze Terraform plan
+	// within the to_dir.
+	DisableToDirDiffCheck bool `hcl:"disable_to_dir_diff_check,optional"`
 	// FromWorkspace is a workspace within FromDir
 	FromWorkspace string `hcl:"from_workspace,optional"`
 	// ToWorkspace is a workspace within ToDir
@@ -56,15 +62,19 @@ func (c *MultiStateMigratorConfig) NewMigrator(o *MigratorOption) (Migrator, err
 		c.ToWorkspace = "default"
 	}
 
-	return NewMultiStateMigrator(c.FromDir, c.ToDir, c.FromWorkspace, c.ToWorkspace, actions, o, c.Force), nil
+	return NewMultiStateMigrator(c.FromDir, c.ToDir, c.FromWorkspace, c.ToWorkspace, actions, o, c.Force, c.DisableFromDirDiffCheck, c.DisableToDirDiffCheck), nil
 }
 
 // MultiStateMigrator implements the Migrator interface.
 type MultiStateMigrator struct {
 	// fromTf is an instance of TerraformCLI which executes terraform command in a fromDir.
 	fromTf tfexec.TerraformCLI
+	// disableFromDirDiffCheck disables the running of Terraform plan in fromDir.
+	disableFromDirDiffCheck bool
 	// fromTf is an instance of TerraformCLI which executes terraform command in a toDir.
 	toTf tfexec.TerraformCLI
+	// disableToDirDiffCheck disables the running of Terraform plan in toDir.
+	disableToDirDiffCheck bool
 	//fromWorkspace is the workspace from which the resource will be migrated
 	fromWorkspace string
 	//toWorkspace is the workspace to which the resource will be migrated
@@ -82,7 +92,7 @@ var _ Migrator = (*MultiStateMigrator)(nil)
 
 // NewMultiStateMigrator returns a new MultiStateMigrator instance.
 func NewMultiStateMigrator(fromDir string, toDir string, fromWorkspace string, toWorkspace string,
-	actions []MultiStateAction, o *MigratorOption, force bool) *MultiStateMigrator {
+	actions []MultiStateAction, o *MigratorOption, force bool, disableFromDirDiffCheck bool, disableToDirDiffCheck bool) *MultiStateMigrator {
 	fromTf := tfexec.NewTerraformCLI(tfexec.NewExecutor(fromDir, os.Environ()))
 	toTf := tfexec.NewTerraformCLI(tfexec.NewExecutor(toDir, os.Environ()))
 	if o != nil && len(o.ExecPath) > 0 {
@@ -91,13 +101,15 @@ func NewMultiStateMigrator(fromDir string, toDir string, fromWorkspace string, t
 	}
 
 	return &MultiStateMigrator{
-		fromTf:        fromTf,
-		toTf:          toTf,
-		fromWorkspace: fromWorkspace,
-		toWorkspace:   toWorkspace,
-		actions:       actions,
-		o:             o,
-		force:         force,
+		fromTf:                  fromTf,
+		disableFromDirDiffCheck: disableFromDirDiffCheck,
+		toTf:                    toTf,
+		disableToDirDiffCheck:   disableToDirDiffCheck,
+		fromWorkspace:           fromWorkspace,
+		toWorkspace:             toWorkspace,
+		actions:                 actions,
+		o:                       o,
+		force:                   force,
 	}
 }
 
@@ -139,34 +151,42 @@ func (m *MultiStateMigrator) plan(ctx context.Context) (*tfexec.State, *tfexec.S
 		planOpts = append(planOpts, "-out="+m.o.PlanOut)
 	}
 
-	// check if a plan in fromDir has no changes.
-	log.Printf("[INFO] [migrator@%s] check diffs\n", m.fromTf.Dir())
-	_, err = m.fromTf.Plan(ctx, fromCurrentState, planOpts...)
-	if err != nil {
-		if exitErr, ok := err.(tfexec.ExitError); ok && exitErr.ExitCode() == 2 {
-			if !m.force {
-				log.Printf("[ERROR] [migrator@%s] unexpected diffs\n", m.fromTf.Dir())
-				return nil, nil, fmt.Errorf("terraform plan command returns unexpected diffs: %s", err)
+	if m.disableFromDirDiffCheck {
+		// check if a plan in fromDir has no changes.
+		log.Printf("[INFO] [migrator@%s] check diffs\n", m.fromTf.Dir())
+		_, err = m.fromTf.Plan(ctx, fromCurrentState, planOpts...)
+		if err != nil {
+			if exitErr, ok := err.(tfexec.ExitError); ok && exitErr.ExitCode() == 2 {
+				if !m.force {
+					log.Printf("[ERROR] [migrator@%s] unexpected diffs\n", m.fromTf.Dir())
+					return nil, nil, fmt.Errorf("terraform plan command returns unexpected diffs: %s", err)
+				}
+				log.Printf("[INFO] [migrator@%s] unexpected diffs, ignoring as force option is true: %s", m.fromTf.Dir(), err)
+			} else {
+				return nil, nil, err
 			}
-			log.Printf("[INFO] [migrator@%s] unexpected diffs, ignoring as force option is true: %s", m.fromTf.Dir(), err)
-		} else {
-			return nil, nil, err
 		}
+	} else {
+		log.Printf("[INFO] [migrator@%s] skipping check diffs\n", m.fromTf.Dir())
 	}
 
-	// check if a plan in toDir has no changes.
-	log.Printf("[INFO] [migrator@%s] check diffs\n", m.toTf.Dir())
-	_, err = m.toTf.Plan(ctx, toCurrentState, planOpts...)
-	if err != nil {
-		if exitErr, ok := err.(tfexec.ExitError); ok && exitErr.ExitCode() == 2 {
-			if !m.force {
-				log.Printf("[ERROR] [migrator@%s] unexpected diffs\n", m.toTf.Dir())
-				return nil, nil, fmt.Errorf("terraform plan command returns unexpected diffs: %s", err)
+	if m.disableToDirDiffCheck {
+		// check if a plan in toDir has no changes.
+		log.Printf("[INFO] [migrator@%s] check diffs\n", m.toTf.Dir())
+		_, err = m.toTf.Plan(ctx, toCurrentState, planOpts...)
+		if err != nil {
+			if exitErr, ok := err.(tfexec.ExitError); ok && exitErr.ExitCode() == 2 {
+				if !m.force {
+					log.Printf("[ERROR] [migrator@%s] unexpected diffs\n", m.toTf.Dir())
+					return nil, nil, fmt.Errorf("terraform plan command returns unexpected diffs: %s", err)
+				}
+				log.Printf("[INFO] [migrator@%s] unexpected diffs, ignoring as force option is true: %s", m.toTf.Dir(), err)
+			} else {
+				return nil, nil, err
 			}
-			log.Printf("[INFO] [migrator@%s] unexpected diffs, ignoring as force option is true: %s", m.toTf.Dir(), err)
-		} else {
-			return nil, nil, err
 		}
+	} else {
+		log.Printf("[INFO] [migrator@%s] skipping check diffs\n", m.toTf.Dir())
 	}
 
 	return fromCurrentState, toCurrentState, nil