naming-kubernetes

A Java naming context for WildFly using Kubernetes as backend for lookups.

JNDI lookups are resolved to configmap or secret keys using the Kubernetes API. Configmaps and secrets should have the following label to be eligible for naming resolution:

k8s.naming.topicus.nl/externalcontext: <name>

JNDI subcontexts have their own configmap/secret. To distinguish different subcontexts the configmap/secret should get the following annotation with the full subcontext path as value:

k8s.naming.topicus.nl/context: <subcontext>

All lookups are first tried to resolve as configmap key. If no configmap key exists for the given JNDI name a secret lookup is performed.

WildFly configuration

The naming-kubernetes module should be placed in the WildFly module directory.

WildFly subsystem configuration:

<subsystem xmlns="urn:jboss:domain:naming:2.0">
	<bindings>
		<external-context name="java:/k8s" module="nl.topicus.naming-kubernetes" class="javax.naming.InitialContext" cache="false">
			<environment>
				<property name="java.naming.factory.initial" value="nl.topicus.naming.kubernetes.KubeCtxFactory"/>
				<property name="java.naming.kubernetes.context" value="<external-context name>"/>
				<property name="java.naming.kubernetes.namespace" value="<kubernetes namespace>"/>
			</environment>
		</external-context>
	</bindings>
	<remote-naming/>
</subsystem>

Enable debug logging for naming-kubernetes:

<logger category="nl.topicus.naming.kubernetes">
	<level name="DEBUG"/>
</logger>

Java types

The values returned from Kubernetes are of the Java type String. JNDI values are of the Java type Object. To expose values as typed Java objects the following type conversion rules are applied:

• Boolean: a true or false (case insensitive)
• Integer: a value containing only the characters 0-9 (no negative numbers, no overflow detection)
• String: A string of text

Compatibility Matrix

	< WildFly 27	>= WildFly 27
naming-kubernetes 2.x	+	-
naming-kubernetes 3.x	-	+

Examples

The following configmap exposes the JNDI name java://k8s/my.jndi.key (k8s is the name of the external-context and has to be defined as a label on the configmap/secret):

apiVersion: v1
kind: ConfigMap
metadata:
  labels:
    k8s.naming.topicus.nl/externalcontext: "k8s"
  name: ConfigMapExample
data:
  my.jndi.key: "naming-kubernetes-sample-value"

The JNDI name java://k8s/my.subcontext/my.jndi.key is exposed by the following configmap:

apiVersion: v1
kind: ConfigMap
metadata:
  labels:
    k8s.naming.topicus.nl/externalcontext: "k8s"
  annotations:
    k8s.naming.topicus.nl/context: "my.subcontext"
  name: ConfigMapSubContextExample
data:
  my.jndi.key: "naming-kubernetes-sample-value"