Feature/license header (#153)

* updated license header check action

* updated action

* updated license checking logic

* action update

* action update

* updated license commit

* commented gpg sign for testing

* updated git details

* removed signing

* Removed autofix

* updated autofix

* common action update

* Implemented auto-fix option

* binary update

* Updated license action

* dockerfile update

* action update

* updated image building

* workflow update

* docker command update

* dockerfile update

* dockerfile update

* added entrypoint

* updated dockerfile

* fixed review comments

* Removed unnecessary logs

* Added documentation

* doc update

Author: harishp8889

.github/workflows/check-license-header.yaml

@@ -11,6 +11,10 @@ name: Common Workflows
 
 on:
   workflow_call:
+    inputs:
+      autofix:
+        required: false
+        type: string
 
 # Set defaults
 env:
@@ -124,3 +128,14 @@ jobs:
   # dependabot_automerge:
   #   name: Automerge Dependabot PRs
   #   uses: dell/common-github-actions/.github/workflows/dependabot-automerge.yml@main
+  
+  check-license-header:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Check license headers
+        uses: dell/common-github-actions/license-checker@main
+        with:
+          autofix: false

.github/workflows/go-common.yml

@@ -0,0 +1,15 @@
+FROM golang:1.24
+
+LABEL "com.github.actions.name"="license-checker"
+LABEL "com.github.actions.description"="Checks for license header"
+LABEL "com.github.actions.icon"="eye"
+LABEL "com.github.actions.color"="gray-dark"
+
+LABEL version="1.0.0"
+
+WORKDIR /app
+
+COPY go.mod go.sum main.go LICENSE-HEADER.txt ./
+RUN go build .
+
+ENTRYPOINT ["/app/license-checker"]

license-checker/Dockerfile

@@ -0,0 +1,17 @@
+/*
+ *
+ * Copyright © 2021-2024 Dell Inc. or its subsidiaries. All Rights Reserved.
+ *
+ * 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.
+ *
+ */

license-checker/LICENSE-HEADER.txt

@@ -0,0 +1,37 @@
+# License header checker GitHub Action
+
+This GitHub Action can be used to check the license header for the source codes (.go files only).
+
+To enable this Action, you can create a .yml file under your repo's .github/workflows directory.
+Simple example:
+
+```yaml
+name: License Header Checker
+
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    branches: [ main ]
+
+jobs:
+
+  check-license-header:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Check license headers
+        uses: dell/common-github-actions/license-checker@main
+        with:
+          autofix: false
+```
+
+Arguments described below -- all are optional:
+
+`autofix` specifies whether to enable auto-fix the missing headers in the source code or not. This is optional. The default value will be `False` if nothing is supplied
+
+Note: To run this action locally clone this repo and run main.go present inside license-checker
+  1. To run in check mode : `./license-checker`
+  2. To run in autofix mode : `./license-checker --auto-fix`

license-checker/README.md

@@ -0,0 +1,13 @@
+name: "License Header Checker"
+description: "Checks for license header"
+
+inputs:
+  autofix:
+    required: false
+    description: "Enable autofix"
+
+runs:
+  using: "docker"
+  image: "Dockerfile"
+  args:
+    - ${{ inputs.autofix }}

license-checker/action.yml

@@ -0,0 +1,3 @@
+module github.com/dell/license-checker
+
+go 1.24

license-checker/go.mod

@@ -0,0 +1,146 @@
+/*
+ *
+ * Copyright © 2025 Dell Inc. or its subsidiaries. All Rights Reserved.
+ *
+ * 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 main
+
+import (
+	"bufio"
+	"flag"
+	"fmt"
+	"io/fs"
+	"os"
+	"path/filepath"
+	"regexp"
+	"strings"
+)
+
+func readLicenseHeader(filePath string) (string, error) {
+	file, err := os.Open(filePath)
+	if err != nil {
+		return "", err
+	}
+	defer file.Close()
+
+	var headerLines []string
+	scanner := bufio.NewScanner(file)
+	for scanner.Scan() {
+		headerLines = append(headerLines, scanner.Text())
+	}
+	if err := scanner.Err(); err != nil {
+		return "", err
+	}
+	return strings.Join(headerLines, "\n"), nil
+}
+
+func checkLicenseHeader(filePath, licenseHeader string) (bool, error) {
+	file, err := os.Open(filePath)
+	if err != nil {
+		return false, err
+	}
+	defer file.Close()
+
+	scanner := bufio.NewScanner(file)
+	headerLines := strings.Split(licenseHeader, "\n")
+	for i := 0; scanner.Scan() && i < len(headerLines); i++ {
+		if !strings.Contains(headerLines[i], "Copyright") {
+			if strings.TrimSpace(scanner.Text()) != strings.TrimSpace(headerLines[i]) {
+				return false, nil
+			}
+		} else {
+			// Check for the copyright year using regex
+			re := regexp.MustCompile(`Copyright © \d{4}`)
+			if !re.MatchString(scanner.Text()) {
+				return false, nil
+			}
+		}
+	}
+	return true, scanner.Err()
+}
+
+func listGoFiles(root string) ([]string, error) {
+	var files []string
+	err := filepath.WalkDir(root, func(path string, dirEntry fs.DirEntry, err error) error {
+		if err != nil {
+			return err
+		}
+		if !dirEntry.IsDir() &&
+			strings.HasSuffix(dirEntry.Name(), ".go") &&
+			!strings.Contains(dirEntry.Name(), "mock") &&
+			!strings.Contains(dirEntry.Name(), "generated") {
+			files = append(files, path)
+		}
+		return nil
+	})
+	return files, err
+}
+func autofixLicenseHeader(filePath, licenseHeader string) error {
+	input, err := os.ReadFile(filePath)
+	if err != nil {
+		return err
+	}
+
+	output := licenseHeader + "\n\n" + string(input)
+	return os.WriteFile(filePath, []byte(output), 0644)
+}
+
+func main() {
+	isAutofixEnabled := flag.Bool("auto-fix", false, "Autofix enabled")
+	flag.Parse()
+
+	licenseFile := "/app/LICENSE-HEADER.txt" // Change this to the path of your license file
+
+	licenseHeader, err := readLicenseHeader(licenseFile)
+	if err != nil {
+		fmt.Println("Error reading license file:", err)
+		return
+	}
+
+	root := "." // Change this to the directory you want to search
+	files, err := listGoFiles(root)
+	if err != nil {
+		fmt.Println("Error:", err)
+		return
+	}
+	fmt.Println("Checking license header for the following files:")
+	for _, file := range files {
+		fmt.Println(file)
+	}
+	var hasLicense bool
+	for _, file := range files {
+		hasLicense, err = checkLicenseHeader(file, licenseHeader)
+		if err != nil {
+			fmt.Printf("Error checking file %s: %v\n", file, err)
+			continue
+		}
+		if !hasLicense {
+			fmt.Printf("Missing or incorrect license header: %s\n", file)
+			//  if auto-fix is enabled then only we will fix the license headers else just report valid header and exit
+			if *isAutofixEnabled {
+				err := autofixLicenseHeader(file, licenseHeader)
+				if err != nil {
+					fmt.Printf("Error updating license header for file %s: %v\n", file, err)
+				} else {
+					fmt.Printf("License header updated for file: %s\n", file)
+				}
+			}
+		}
+	}
+	if !hasLicense {
+		os.Exit(1)
+	}
+}