Spring Boot and Camel using ConfigMaps and Secrets

This quickstart demonstrates how to configure a Spring-Boot application using Kubernetes ConfigMaps and Secrets.

A route generates sample messages that are delivered to a list of recipient endpoints configured through a property named quickstart.recipients in the src/main/resources/application.properties file. The property can be overridden using a Kubernetes ConfigMap object. As soon as a ConfigMap named camel-config (containing a property named application.properties) is created or changed in the namespace, an application-context refresh event will be triggered and the logs will reflect the new configuration. A sample ConfigMap (sample-configmap.yml) is contained in this repository (it changes the configuration to use all available endpoints in the recipientList).

The quickstart will run on Openshift using a ServiceAccount named qs-camel-config, with the view role granted. This way, the application is allowed to read the ConfigMap and to listen for changes in the current Openshift project.

Secrets can also be used to configure the application (a sample username/password combination is configured using secrets in this quickstart). Unlike the ConfigMap objects, secrets require higher permissions in order to be read using the Openshift APIs. To overcome this security limitation, the approach used in this quickstart is to mount the secret as a volume in the Pod and configure its location in the spring-cloud config file (src/main/resources/bootstrap.yml).

A sample secret (sample-secret.yml) is contained in this repository (it just replaces the username wrong-username with myuser).

Note: a secret named camel-config must be present in the namespace before the application is deployed (otherwise the container remains in a pending status, waiting for it).

Building

The example can be built with

mvn clean install

Running the example locally

The example can be run locally using the following Maven goal:

mvn spring-boot:run

Running the example in Kubernetes

It is assumed that Kubernetes is already running. If not you can find details how to get started.

Assuming your current shell is connected to Kubernetes or OpenShift so that you can type a command like

kubectl get pods
# for Openshift:
# oc get pods

The following command will create the (required) secret:

kubectl create -f sample-secret.yml
# for Openshift:
# oc create -f sample-secret.yml

The following command can be used to create the ConfigMap (the ConfigMap can be also created after the application has been deployed, to see the live-reload feature in action):

kubectl create -f sample-configmap.yml
# for Openshift:
# oc create -f sample-configmap.yml

Then the following command will package your app and run it on Kubernetes:

mvn fabric8:run

To list all the running pods:

oc get pods

Then find the name of the pod that runs this quickstart, and output the logs from the running pods with:

oc logs <name of pod>

You can also use the fabric8 developer console to manage the running pods, and view logs and much more.

Integration Testing

The example includes a fabric8 arquillian Kubernetes Integration Test. Once the container image has been built and deployed in Kubernetes, the integration test can be run with:

mvn test -Dtest=*KT

The test is disabled by default and has to be enabled using -Dtest. Integration Testing and Fabric8 Arquillian Extension provide more information on writing full fledged black box integration tests for Kubernetes.

More details

You can find more details about running this quickstart on the website. This also includes instructions how to change the Docker image user and registry.