INTRODUCTION

This repo is meant to build a docker image based on Alpine Linux that can be used for network configurations via environment variables

Environment variables supported

For ipv4

To set an ipv4 address on an interface, the following environment variables must be present:

NET_IFNAME NET_IPV4_ADDRESS NET_IPV4_NETMASK

Optionally routes can be added if the following were present:

NET_IPV4_DEST_PREFIX NET_IPV4_GATEWAY

If NET_SEND_GRATUITOUS_ARP is set to a number, an unsolicated gratuitious arp packets will be sent over the interface once it get configured (number of packets to be sent is from the env. variable)

For ipv6

To set an ipv6 address on an interface, the following environment variables must be present:

NET_IFNAME NET_IPV6_ADDRESS NET_IPV6_NETMASK

Optionally routes can be added if the following were present:

NET_IPV6_DEST_PREFIX NET_IPV6_GATEWAY

Example:

apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: app1
  namespace: default
spec:
  replicas: 1
  template:
    metadata:
      annotations:
        networks: '[ { "name": "green" }, { "name": "blue" } ]'
      labels:
        app: app1
    spec:
      affinity:
        podAntiAffinity:
          requiredDuringSchedulingIgnoredDuringExecution:
          - labelSelector:
              matchExpressions:
                - key: app
                  operator: In
                  values:
                  - app2
            topologyKey: "kubernetes.io/hostname"
      initContainers:
        - name: net-setup-net1
          image: kaloom/alpine:3.9
          env:
            - name: NET_IFNAME
              value: "net9f27410725ab" # green net
            - name: NET_IPV4_ADDRESS
              value: "192.168.42.10"
            - name: NET_IPV4_NETMASK
              value: "24"
            - name: "NET_SEND_GRATUITOUS_ARP"
              value: "3"
            - name: NET_IPV6_ADDRESS
              value: "fd10:42::1"
            - name: NET_IPV6_NETMASK
              value: "64"
          command:
            - "/opt/kaloom/bin/config-network.sh"
          securityContext:
            capabilities:
              add:
                - NET_ADMIN
                - NET_RAW
        - name: net-setup-net2
          image: kaloom/alpine:3.9
          env:
            - name: NET_IFNAME
              value: "net48d6215903df" # blue net
            - name: NET_IPV4_ADDRESS
              value: "192.168.43.10"
            - name: NET_IPV4_NETMASK
              value: "24"
            - name: "NET_SEND_GRATUITOUS_ARP"
              value: "3"
            - name: NET_IPV6_ADDRESS
              value: "fd10:43::1"
            - name: NET_IPV6_NETMASK
              value: "64"
          command:
            - "/opt/kaloom/bin/config-network.sh"
          securityContext:
            capabilities:
              add:
                - NET_ADMIN
                - NET_RAW
      containers:
      - name: alpine-container
        image: kaloom/alpine:3.9
        imagePullPolicy: IfNotPresent
        args:
        - top