[dmt] Create changelog rule (#318)

Signed-off-by: Sinelnikov Michail <mikhail.sinelnikov@flant.com>
Co-authored-by: Sinelnikov Michail <mikhail.sinelnikov@flant.com>

Author: RottenRat

internal/module/module.go

@@ -311,6 +311,7 @@ func mapModuleRules(linterSettings *pkg.LintersSettings, configSettings *config.
 	rules.LicenseRule.SetLevel(globalRules.LicenseRule.Impact, fallbackImpact)
 	rules.RequarementsRule.SetLevel(globalRules.RequarementsRule.Impact, fallbackImpact)
 	rules.LegacyReleaseFileRule.SetLevel(globalRules.LegacyReleaseFileRule.Impact, fallbackImpact)
+	rules.ChangelogRule.SetLevel(globalRules.ChangelogRule.Impact, fallbackImpact)
 }
 
 // mapTemplatesRules configures Templates linter rules

pkg/config.go

@@ -220,6 +220,7 @@ type ModuleLinterRules struct {
 	LicenseRule           RuleConfig
 	RequarementsRule      RuleConfig
 	LegacyReleaseFileRule RuleConfig
+	ChangelogRule         RuleConfig
 }
 type OSSRuleSettings struct {
 	Disable bool

pkg/config/global/global.go

@@ -109,6 +109,7 @@ type ModuleLinterRules struct {
 	LicenseRule           RuleConfig `mapstructure:"license"`
 	RequarementsRule      RuleConfig `mapstructure:"requarements"`
 	LegacyReleaseFileRule RuleConfig `mapstructure:"legacy-release-file"`
+	ChangelogRule         RuleConfig `mapstructure:"changelog"`
 }
 
 type TemplatesLinterConfig struct {

pkg/linters/module/README.md

@@ -8,7 +8,7 @@ The Module linter performs automated checks on Deckhouse modules to validate con
 
 ## Rules
 
-The Module linter includes **7 validation rules**:
+The Module linter includes **8 validation rules**:
 
 | Rule | Description | Configurable |
 |------|-------------|--------------|
@@ -19,6 +19,7 @@ The Module linter includes **7 validation rules**:
 | [**license**](#license) | Validates license headers in source files | ✅ Yes |
 | [**requirements**](#requirements) | Validates version requirements for features | ❌ No |
 | [**legacy-release-file**](#legacy-release-file) | Checks for deprecated `release.yaml` file | ❌ No |
+| [**changelog**](#changelog) | Validates changelog file presence and content | ❌ No |
 
 ---
 
@@ -531,3 +532,52 @@ update:
     - from: "1.17"
       to: "1.20"
 ```
+
+---
+
+### Changelog
+
+Validates changelog.yaml file presence and content in modules.
+
+**Purpose:** Ensures modules have a changelog file that documents changes and version history. This maintains transparency about module evolution and helps users understand what changes are included in each version.
+
+**Checks:**
+- ✅ `changelog.yaml` file must exist in module root
+- ✅ File must not be empty (size > 0 bytes)
+
+**Validation Logic:**
+- File `changelog.yaml` is required in the module root directory
+- File must contain content (not be empty)
+- Missing or empty files generate appropriate error messages
+
+**Examples:**
+
+```yaml
+# changelog.yaml - Valid changelog
+---
+features:
+  Linting:
+    Module:
+      - Added new changelog validation rule to ensure proper changelog format
+      - Enhanced module YAML file checking with additional validation rules
+      - Improved license checking functionality with better error reporting
+      - Added support for restricting UpdateMode to Auto in module configurations
+fixes:
+  Linting:
+    Module:
+      - Fixed install output formatting issues
+      - Corrected changelog rule validation logic
+      - Resolved false positives in module YAML validation
+chore:
+  Dependencies:
+    - Updated helm.sh/helm/v3 dependency from 3.18.4 to 3.18.5
+  Linting:
+    - Refactored changelog validation code for better maintainability
+
+```
+
+**Error Examples:**
+```
+❌ changelog.yaml file is missing
+❌ changelog.yaml file is empty
+```

pkg/linters/module/module.go

@@ -56,6 +56,7 @@ func (l *Module) Run(m *module.Module) {
 		CheckFiles(m, errorList.WithMaxLevel(l.cfg.Rules.LicenseRule.GetLevel()))
 	rules.NewRequirementsRule().CheckRequirements(m.GetPath(), errorList.WithMaxLevel(l.cfg.Rules.RequarementsRule.GetLevel()))
 	rules.NewLegacyReleaseFileRule().CheckLegacyReleaseFile(m.GetPath(), errorList.WithMaxLevel(l.cfg.Rules.LegacyReleaseFileRule.GetLevel()))
+	rules.NewChangelogRule().CheckChangelog(m.GetPath(), errorList.WithMaxLevel(l.cfg.Rules.ChangelogRule.GetLevel()))
 }
 
 func (l *Module) Name() string {

pkg/linters/module/rules/changelog.go

@@ -0,0 +1,69 @@
+/*
+Copyright 2025 Flant JSC
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package rules
+
+import (
+	errs "errors"
+	"fmt"
+	"os"
+	"path/filepath"
+
+	"github.com/deckhouse/dmt/pkg"
+	"github.com/deckhouse/dmt/pkg/errors"
+)
+
+const (
+	ChangelogRuleName = "changelog"
+	changelogFilename = "changelog.yaml"
+)
+
+func NewChangelogRule() *ChangelogRule {
+	return &ChangelogRule{
+		RuleMeta: pkg.RuleMeta{
+			Name: ChangelogRuleName,
+		},
+	}
+}
+
+type ChangelogRule struct {
+	pkg.RuleMeta
+}
+
+func (r *ChangelogRule) CheckChangelog(modulePath string, errorList *errors.LintRuleErrorsList) {
+	errorList = errorList.WithRule(r.GetName())
+
+	changelogPath := filepath.Join(modulePath, changelogFilename)
+	err := checkFile(changelogPath)
+	if err != nil {
+		errorList.WithFilePath(changelogFilename).Error(err.Error())
+	}
+}
+
+func checkFile(filePath string) error {
+	stat, err := os.Stat(filePath)
+	if errs.Is(err, os.ErrNotExist) {
+		return fmt.Errorf("changelog.yaml file does not exist: %w", err)
+	}
+	if err != nil {
+		return fmt.Errorf("failed to stat changelog.yaml file: %w", err)
+	}
+	if stat.Size() == 0 {
+		return fmt.Errorf("changelog.yaml file is empty")
+	}
+
+	return nil
+}

pkg/linters/module/rules/changelog_test.go

@@ -0,0 +1,77 @@
+/*
+Copyright 2025 Flant JSC
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package rules
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"github.com/deckhouse/dmt/pkg/errors"
+)
+
+func TestChangelogRule_CheckChangelog(t *testing.T) {
+	tests := []struct {
+		name         string
+		fileContent  string
+		createFile   bool
+		expectErrors int
+	}{
+		{
+			name:         "changelog.yaml file missing",
+			createFile:   false,
+			expectErrors: 1,
+		},
+		{
+			name:         "changelog.yaml file empty",
+			fileContent:  "",
+			createFile:   true,
+			expectErrors: 1,
+		},
+		{
+			name:         "changelog.yaml file present and non-empty",
+			fileContent:  "# Changelog\n\n## v1.0.0\n- Initial release",
+			createFile:   true,
+			expectErrors: 0,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			tempDir := t.TempDir()
+			if tt.createFile {
+				err := os.WriteFile(filepath.Join(tempDir, changelogFilename), []byte(tt.fileContent), 0600)
+				require.NoError(t, err)
+			}
+
+			rule := NewChangelogRule()
+			errorList := errors.NewLintRuleErrorsList()
+
+			rule.CheckChangelog(tempDir, errorList)
+
+			if tt.expectErrors > 0 {
+				assert.True(t, errorList.ContainsErrors(), "Expected errors but got none")
+				assert.Len(t, errorList.GetErrors(), tt.expectErrors)
+			} else {
+				assert.False(t, errorList.ContainsErrors(), "Expected no errors but got some")
+			}
+		})
+	}
+}