Kubernetes version 1.5.2 or higher is recommended, as support for TPRs have improved vastly in that release. Earlier versions had several issues relating to TPR handling, resulting in zombie TPRs being left behind. If using an earlier version it may be necessary to remove TPR’s before starting the controller:

$ kubectl delete -n <namespace> thirdpartyresource routing-rule.amalgam8.io

Prerequisites and Caveats

Before beginning working through the examples and demos, please confirm all container images for the control plane, helloworld and bookinfo demo applications, are stored in a docker image registry accessible to the Kubernetes cluster. By default, the latest images are hosted in the amalgam8 docker hub image repository, but if you’re building a different version, be sure to push the modified images and change the resource manifests accordingly.

Once the below make completes, tag and push the newly built images to an image repository accessible to the Kubernetes cluster. It is further advised that imagePullPolicy is set to Always in all yaml files, to ensure the latest are indeed used in testing.

 $ git clone [email protected]:amalgam8/amalgam8.git
 $ cd amalgam8
 # trick makefile to generate all with a "latest" version tag by setting version to "vlatest"
 $ APP_VER_ABBR=vlatest make build.controller build.sidecar build.exampleapps dockerize.sidecar.envoy.ubuntu dockerize.controller

Native Kubernetes Integration

When deployed on Kubernetes, Amalgam8 provides a near native experience by reusing native Kubernetes tools and fucntions to run and manage its control plane components. The Service registration and discovery functionality leverages Kubernetes built in kubernetes service registry and discovery, and the Route Controller uses Kubernetes Third Party Resources to store routing rules, thus enabling familiar access using kubectl command line.

Sidecar Configuration

The Amalgam8 sidecar configuration need to change to match the fact that it is running in in a Kubernetes cluster. Please refer also to sidecar configuration.

  • Service instance registration is not required, pods are automatically registered by Kubernetes.
  • The discovery_adapter and rules_adapter flags should be set to kubernetes
  • The access URLs and token are not required (they are automatically retrieved from the pod). The default, in-cluster, configuration may be overridden by setting the kubernetes_url and kubernetes_token flags.
  • The sidecar will fetch rules and service instance information from the default namespace. This may be overridden by setting the kubernetes_namespace flag.
  • Service name and labels may be specified using the service flag, as before. Alternately, if the kubernetes_pod_name is set, the source service name and tags are automatically retrieved from the pod’s service association and labels. Note that if a pod is mapped to multiple Kubernetes service, an arbitrary service identity will be selected from the list. Tags are automatically generated from the pod’s labels by converting each label to a tag whose format is key=value (or simple key if value is undefined). The key=value format should be used in defininig routing rules.
  • Kubernetes service names are used directly in defining rule target services.