Document license and make license-headers configurable

Author: SuperSandro2000

README.md

@@ -75,6 +75,7 @@ The config file has the following sections:
 * [golang](#golang)
 * [golangciLint](#golangcilint)
 * [goReleaser](#goreleaser)
+* [license-headers](#license-headers)
 * [makefile](#makefile)
 * [metadata](#metadata)
 * [nix](#nix)
@@ -289,6 +290,28 @@ The `nameTemplate` option can be used to change the name of uploaded release art
 
 The `files` option can be used to add extra files. For backwards compatibility it defaults to `[ CHANGELOG.md, LICENSE, README.md ]`.
 
+### `license`
+
+```yaml
+license:
+  addHeaders: true
+  checkDependencies: true
+  copyright: 'SAP SE or an SAP affiliate company'
+  spdx: Apache-2.0
+```
+
+`license` contains settings related to the license of the project and specifically license header generation.
+
+`addHeaders` controls whether license headers are added and checked in source files.
+
+`checkDependencies` controls whether dependency licenses are checked for compliance.
+
+`copyright` is the text to be used in the copyright line of the license header.
+
+`spdx` is the SPDX short identifier of the license to be used in the license header.
+
+In SAP Cloud Infrastructure projects all checks are enabled by default and the copyright and SPDX identifier are prefilled accordingly.
+
 ### `makefile`
 
 ```yaml

internal/core/config.go

@@ -256,7 +256,10 @@ type ControllerGen struct {
 }
 
 type LicenseConfig struct {
-	Copyright Option[string] `yaml:"copyright"`
+	AddHeaders        Option[bool]   `yaml:"addHeaders"`
+	CheckDependencies Option[bool]   `yaml:"checkDependencies"`
+	Copyright         Option[string] `yaml:"copyright"`
+	SPDX              Option[string] `yaml:"spdx"`
 }
 
 type MakefileConfig struct {

internal/makefile/makefile.go

@@ -135,16 +135,16 @@ endif
 		prepareStaticRecipe = append(prepareStaticRecipe, "install-shellcheck")
 	}
 
-	if isSAPCC {
-		if isGolang {
-			prepare.addRule(rule{
-				description: "Install-go-licence-detector required by check-dependency-licenses/static-check",
-				phony:       true,
-				target:      "install-go-licence-detector",
-				recipe:      installTool("go-licence-detector", "go.elastic.co/go-licence-detector@latest"),
-			})
-			prepareStaticRecipe = append(prepareStaticRecipe, "install-go-licence-detector")
-		}
+	if isGolang && (cfg.License.AddHeaders.UnwrapOr(isSAPCC) || cfg.License.CheckDependencies.UnwrapOr(isSAPCC)) {
+		prepare.addRule(rule{
+			description: "Install-go-licence-detector required by check-dependency-licenses/static-check",
+			phony:       true,
+			target:      "install-go-licence-detector",
+			recipe:      installTool("go-licence-detector", "go.elastic.co/go-licence-detector@latest"),
+		})
+		prepareStaticRecipe = append(prepareStaticRecipe, "install-go-licence-detector")
+	}
+	if cfg.License.AddHeaders.UnwrapOr(isSAPCC) {
 		prepare.addRule(rule{
 			description: "Install addlicense required by check-license-headers/license-headers/static-check",
 			phony:       true,
@@ -490,7 +490,7 @@ endif
 		allSourceFilesExpr = `$(shell find -name *.rs)`
 	}
 
-	if isSAPCC {
+	if cfg.License.AddHeaders.UnwrapOr(isSAPCC) {
 		var ignoreOptions []string
 		if cfg.GitHubWorkflow != nil {
 			for _, pattern := range cfg.GitHubWorkflow.License.IgnorePatterns {
@@ -592,11 +592,16 @@ endif
 		}
 	}
 
+	staticCheckPrerequisites := []string{"run-shellcheck"}
+
 	if isGolang {
 		// add target for static code checks
-		staticCheckPrerequisites := []string{"run-shellcheck", "run-golangci-lint", "run-modernize"}
-		if isSAPCC {
-			staticCheckPrerequisites = append(staticCheckPrerequisites, "check-dependency-licenses", "check-license-headers")
+		staticCheckPrerequisites = append(staticCheckPrerequisites, "run-golangci-lint", "run-modernize")
+		if cfg.License.CheckDependencies.UnwrapOr(isSAPCC) {
+			staticCheckPrerequisites = append(staticCheckPrerequisites, "check-dependency-licenses")
+		}
+		if cfg.License.AddHeaders.UnwrapOr(isSAPCC) {
+			staticCheckPrerequisites = append(staticCheckPrerequisites, "check-license-headers")
 		}
 		test.addRule(rule{
 			description:   "Run static code checks (internal option to enforce --keep-going)",