feat: Supporting no_run in exclude block (#4574)

Author: yhakbar

cli/commands/run/run.go

@@ -308,7 +308,12 @@ func runTerragruntWithConfig(
 	r *report.Report,
 	target *Target,
 ) error {
-	// Add extra_arguments to the command
+	if cfg.Exclude != nil && cfg.Exclude.ShouldPreventRun(opts.TerraformCommand) {
+		l.Infof("Early exit in terragrunt unit %s due to exclude block with no_run = true", opts.WorkingDir)
+
+		return nil
+	}
+
 	if cfg.Terraform != nil && cfg.Terraform.ExtraArgs != nil && len(cfg.Terraform.ExtraArgs) > 0 {
 		args := FilterTerraformExtraArgs(l, opts, cfg)
 

config/config.go

@@ -491,6 +491,10 @@ func (cfg *TerragruntConfig) WriteTo(w io.Writer) (int64, error) {
 			excludeBody.SetAttributeValue("actions", excludeAsCty.GetAttr("actions"))
 		}
 
+		if cfg.Exclude.NoRun != nil {
+			excludeBody.SetAttributeValue("no_run", excludeAsCty.GetAttr("no_run"))
+		}
+
 		excludeBody.SetAttributeValue("if", excludeAsCty.GetAttr("if"))
 
 		rootBody.AppendBlock(excludeBlock)

config/exclude.go

@@ -17,11 +17,12 @@ const (
 )
 
 // bool values to be used as booleans.
-var boolFlagValues = []string{"if", "exclude_dependencies"}
+var boolFlagValues = []string{"if", "exclude_dependencies", "no_run"}
 
 // ExcludeConfig configurations for hcl files.
 type ExcludeConfig struct {
 	ExcludeDependencies *bool    `cty:"exclude_dependencies" hcl:"exclude_dependencies,attr" json:"exclude_dependencies"`
+	NoRun               *bool    `cty:"no_run" hcl:"no_run,attr" json:"no_run"`
 	Actions             []string `cty:"actions" hcl:"actions,attr" json:"actions"`
 	If                  bool     `cty:"if" hcl:"if,attr" json:"if"`
 }
@@ -49,12 +50,18 @@ func (e *ExcludeConfig) IsActionListed(action string) bool {
 	return false
 }
 
+// ShouldPreventRun checks if the unit should be prevented from running based on the no_run attribute and current action.
+func (e *ExcludeConfig) ShouldPreventRun(action string) bool {
+	return e.NoRun != nil && *e.NoRun && e.If && e.IsActionListed(action)
+}
+
 // Clone returns a new instance of ExcludeConfig with the same values as the original.
 func (e *ExcludeConfig) Clone() *ExcludeConfig {
 	return &ExcludeConfig{
 		If:                  e.If,
 		Actions:             e.Actions,
 		ExcludeDependencies: e.ExcludeDependencies,
+		NoRun:               e.NoRun,
 	}
 }
 
@@ -67,6 +74,7 @@ func (e *ExcludeConfig) Merge(exclude *ExcludeConfig) {
 	}
 
 	e.ExcludeDependencies = exclude.ExcludeDependencies
+	e.NoRun = exclude.NoRun
 }
 
 // evaluateExcludeBlocks evaluates the exclude block in the parsed file.

docs-starlight/src/content/docs/04-reference/01-hcl/02-blocks.mdx

@@ -1488,9 +1488,10 @@ Syntax:
 # terragrunt.hcl
 
 exclude {
-    if = <boolean expression>           # Boolean expression to determine exclusion.
-    actions = ["<action>", ...]         # List of actions to exclude (e.g., "plan", "apply", "all", "all_except_output").
-    exclude_dependencies = <boolean>    # Boolean to determine if dependencies should also be excluded.
+    if                   = <boolean>         # Boolean to determine exclusion.
+    no_run               = <boolean>         # Boolean to prevent the unit from running (even when not using `--all`).
+    actions              = ["<action>", ...] # List of actions to exclude (e.g., "plan", "apply", "all", "all_except_output").
+    exclude_dependencies = <boolean>         # Boolean to determine if dependencies should also be excluded.
 }
 ```
 
@@ -1501,6 +1502,7 @@ Attributes:
 | `if`                   | boolean      | Condition to dynamically determine whether the unit should be excluded.                                                 |
 | `actions`              | list(string) | Specifies which actions to exclude when the condition is met. Options: `plan`, `apply`, `all`, `all_except_output` etc. |
 | `exclude_dependencies` | boolean      | Indicates whether the dependencies of the excluded unit should also be excluded (default: `false`).                     |
+| `no_run`               | boolean      | When `true` and `if` is `true`, prevents the unit from running entirely for both single unit commands and `run --all` commands, but only when the current action matches the `actions` list. |
 
 Examples:
 
@@ -1542,6 +1544,18 @@ exclude {
 
 This setup is useful for scenarios where output evaluation is still needed, even if other actions like `plan` or `apply` are excluded.
 
+```hcl
+# terragrunt.hcl
+
+exclude {
+    if      = true
+    no_run  = true
+    actions = ["plan"]
+}
+```
+
+This configuration prevents the unit from running when `if` is `true` AND the current action is "plan". The `no_run` attribute works for both single unit commands (like `terragrunt plan`) and `run --all` commands (like `terragrunt run --all plan`), but only when the current action matches the `actions` list.
+
 Consider using this for units that are expensive to continuously update, and can be opted in when necessary.
 
 ## errors

docs/_docs/04_reference/04-config-blocks-and-attributes.md

@@ -1494,9 +1494,10 @@ Syntax:
 
 ```hcl
 exclude {
-    if = <boolean expression>           # Boolean expression to determine exclusion.
-    actions = ["<action>", ...]         # List of actions to exclude (e.g., "plan", "apply", "all", "all_except_output").
-    exclude_dependencies = <boolean>    # Boolean to determine if dependencies should also be excluded.
+    if                   = <boolean>          # Boolean to determine exclusion.
+    no_run               = <boolean>          # Boolean to prevent the unit from running (even when not using `--all`).
+    actions              = ["<action>", ...]  # List of actions to exclude (e.g., "plan", "apply", "all", "all_except_output").
+    exclude_dependencies = <boolean>          # Boolean to determine if dependencies should also be excluded.
 }
 ```
 
@@ -1507,6 +1508,7 @@ Attributes:
 | `if`                   | boolean      | Condition to dynamically determine whether the unit should be excluded.                                                 |
 | `actions`              | list(string) | Specifies which actions to exclude when the condition is met. Options: `plan`, `apply`, `all`, `all_except_output` etc. |
 | `exclude_dependencies` | boolean      | Indicates whether the dependencies of the excluded unit should also be excluded (default: `false`).                     |
+| `no_run`               | boolean      | When `true` and `if` is `true`, prevents the unit from running entirely for both single unit commands and `run --all` commands, but only when the current action matches the `actions` list. |
 
 Examples:
 
@@ -1542,6 +1544,16 @@ exclude {
 
 This setup is useful for scenarios where output evaluation is still needed, even if other actions like `plan` or `apply` are excluded.
 
+```hcl
+exclude {
+    if      = true
+    no_run  = true
+    actions = ["plan"]
+}
+```
+
+This configuration prevents the unit from running when `if` is `true` AND the current action is "plan". The `no_run` attribute works for both single unit commands (like `terragrunt plan`) and `run --all` commands (like `terragrunt run --all plan`), but only when the current action matches the `actions` list.
+
 Consider using this for units that are expensive to continuously update, and can be opted in when necessary.
 
 ### errors

test/fixtures/exclude/no-run/conditional-no-run-unit/main.tf

@@ -0,0 +1 @@
+

test/fixtures/exclude/no-run/conditional-no-run-unit/terragrunt.hcl

@@ -0,0 +1,13 @@
+terraform {
+  source = "."
+}
+
+feature "enable_unit" {
+  default = false
+}
+
+exclude {
+  if      = !feature.enable_unit.value
+  no_run  = true
+  actions = ["all"]
+}

test/fixtures/exclude/no-run/no-run-independent/main.tf

@@ -0,0 +1 @@
+

test/fixtures/exclude/no-run/no-run-independent/terragrunt.hcl

@@ -0,0 +1,9 @@
+terraform {
+  source = "."
+}
+
+exclude {
+  if      = true
+  no_run  = true
+  actions = ["plan"]
+}

test/fixtures/exclude/no-run/no-run-unit/main.tf

@@ -0,0 +1 @@
+