Disco-pod

A pod discovery sidecar for Kubernetes

This lib is very light (30 lines of simple javascript)

Installation

It is intended to run as a sidecar of your app in a kubernetes pod, with zeromq

      containers:
        - name: disco-pod
          image: hydre/disco-pod
          imagePullPolicy: IfNotPresent
          tty: true
          env:
            - name: DEBUG
              value: disco-pod*
            - name: REQUEST_PORT
              value: {{ .Values.disco-pod.config.REQUEST_PORT }}
            - name: SUBSCRIBE_PORT
              value: {{ .Values.disco-pod.config.SUBSCRIBE_PORT }}
            - name: LABEL
              value: {{ .Values.disco-pod.config.ENDPOINT_NAME }}

• REQUEST_PORT: when your app boot you must zmq.request the pods ip lists through zeromq to tcp://0.0.0.0:REQUEST_PORT
• PUBLISH_PORT: here you can zmq.subscribe to receive updates when the peer list changes
• LABEL: Label of the targetted pod

You will receive ADDED / MODIFIED / DELETED peers update, note that ADDED might not always contains the ip if the pod is started but not ready. You should maintain a Set of peers and when receiving an ip, add to this set or delete