chore(build): add verbose flag for Kaniko builds

docs/modules/ROOT/pages/traits/builder.adoc

@@ -27,6 +27,10 @@ The following configuration options are available:
 | bool
 | Can be used to enable or disable a trait. All traits share this common property.
 
+| builder.verbose
+| bool
+| Enable verbose logging on build components that support it (e.g. Kaniko build pod).
+
 |===
 
 // End of autogenerated code - DO NOT EDIT! (configuration)

docs/modules/ROOT/pages/traits/jolokia.adoc

@@ -33,7 +33,7 @@ applicable when `protocol` is `https` and `use-ssl-client-authentication` is `tr
 (default `/var/run/secrets/kubernetes.io/serviceaccount/ca.crt` for OpenShift).
 
 | jolokia.client-principal
-| string
+| []string
 | The principal which must be given in a client certificate to allow access to the Jolokia endpoint,
 applicable when `protocol` is `https` and `use-ssl-client-authentication` is `true`
 (default `clientPrincipal=cn=system:master-proxy` for OpenShift).

pkg/trait/builder.go

@@ -45,6 +45,8 @@ const builderDir = "/builder"
 // +camel-k:trait=builder
 type builderTrait struct {
 	BaseTrait `property:",squash"`
+	// Enable verbose logging on build components that support it (e.g. Kaniko build pod).
+	Verbose bool `property:"verbose"`
 }
 
 func newBuilderTrait() *builderTrait {
@@ -213,6 +215,10 @@ func (t *builderTrait) kanikoTask(e *Environment) (*v1.KanikoTask, error) {
 	args := make([]string, 0, len(baseArgs))
 	args = append(args, baseArgs...)
 
+	if t.Verbose {
+		args = append(args, "-v=debug")
+	}
+
 	if e.Platform.Status.Build.Registry.Insecure {
 		args = append(args, "--insecure")
 		args = append(args, "--insecure-pull")