build(cli): Add debug build option

.gitignore

@@ -5,6 +5,7 @@
 *.so
 *.dylib
 /trivy
+/trivy-debug
 
 ## chart release
 .cr-release-packages

docs/community/contribute/pr.md

@@ -18,10 +18,17 @@ Install the necessary tools for development by following their respective instal
 After making changes to the Go source code, build the project with the following command:
 
 ```shell
-$ mage build
+$ mage build:prod
 $ ./trivy -h
 ```
 
+Or if you want to use [delve](https://github.com/go-delve/delve) for debugging, build with the following command:
+
+```shell
+$ mage build:dev
+$ dlv exec ./trivy-debug -h
+```
+
 ### Lint
 You must pass the linter checks:
 

docs/community/contribute/vulnerability-database/add-vulnerability-source.md

@@ -123,7 +123,7 @@ This allows you to verify that your vulnerabilities are correctly stored in the
 
 ```bash
 # Build Trivy with your changes
-mage build
+mage build:prod
 
 # Use your local database
 ./trivy image --skip-db-update --cache-dir /path/to/cache your-test-image

magefiles/magefile.go

@@ -47,12 +47,20 @@ func version() (string, error) {
 	return strings.TrimPrefix(ver, "v"), nil
 }
 
-func buildLdflags() (string, error) {
+func buildLdflags(debug bool) (string, error) {
 	ver, err := version()
 	if err != nil {
 		return "", err
 	}
-	return fmt.Sprintf("-s -w -X=github.com/aquasecurity/trivy/pkg/version/app.ver=%s", ver), nil
+	var build string
+
+	if debug {
+		build = "-X=github.com/aquasecurity/trivy/pkg/version/app.ver=%s"
+	} else {
+		build = "-s -w -X=github.com/aquasecurity/trivy/pkg/version/app.ver=%s"
+	}
+
+	return fmt.Sprintf(build, ver), nil
 }
 
 type Tool mg.Namespace
@@ -374,28 +382,49 @@ func Tidy() error {
 	return sh.RunV("go", "mod", "tidy")
 }
 
-// Build builds Trivy
-func Build() error {
+type Build mg.Namespace
+
+// Prod build Trivy without debug symbols
+func (b Build) Prod() error {
+	fmt.Println("Building Trivy production binary")
+	return build(false)
+}
+
+// Dev build Trivy with debug symbols
+func (b Build) Dev() error {
+	fmt.Println("Building Trivy debug binary")
+	return build(true)
+}
+
+func build(debug bool) error {
 	if updated, err := target.Dir("trivy", "pkg", "cmd"); err != nil {
 		return err
 	} else if !updated {
 		return nil
 	}
 
-	ldflags, err := buildLdflags()
+	execName := "trivy"
+	gcflags := ""
+	if debug {
+		execName = "trivy-debug"
+		gcflags = "-gcflags=all=-N -l"
+	}
+
+	ldflags, err := buildLdflags(debug)
 	if err != nil {
 		return err
 	}
 	wd, err := os.Getwd()
 	if err != nil {
 		return err
 	}
-	return sh.RunWith(ENV, "go", "build", "-ldflags", ldflags, filepath.Join(wd, "cmd", "trivy"))
+	return sh.RunWith(ENV, "go", "build", "-o", execName, "-ldflags", ldflags,
+		gcflags, filepath.Join(wd, "cmd", "trivy"))
 }
 
 // Install installs Trivy
 func Install() error {
-	ldflags, err := buildLdflags()
+	ldflags, err := buildLdflags(false)
 	if err != nil {
 		return err
 	}