Migrating to Configurable Networks

This documentation describes how to migrate to configurable virtual networks.

Migration Use Case

Configurable virtual networks require subnet pools and local IPAM.

If you have installed release 3.0 using Apcera Installer, configurable networks are the default; no migration is required.

If you upgrade to release 3.0 and you want to use configurable networks, by following the migration steps you can migrate jobs from virtual networks created using global IPAM to configurable networks created using local IPAM by leaving the old virtual network and joining the new network.

Migration Steps

To migrate jobs from old networks to configurable networks:

  1. Enable local IPAM in cluster.conf and redeploy your cluster.
  2. Create one or more configurable networks using the default system subnet pool or a custom pool.
  3. For jobs in the virtual networks you want to migrate, leave the old network.
  4. Join the jobs to the new virtual network(s).

Using Local IPAM

The Apcera Platform uses IP address management (IPAM) technology to allocate IP addresses to job instances in virtual networks.

In releases 2.6 and earlier, IPAM is performed globally by the Job Manager. In release 3.0, you can enable local IPAM so that each Instance Manager (IM) controls IP adddresses for the containers it hosts. Local IPAM is required to use configurable networks.

You can toggle between the two types of IPAM (global or local), and jobs can join/leave both types of networks in the cluster, but you won't be able to create new networks of the type that is not enabled. The only type of new networks that can be created is the type set by cluster.conf.

If you previously enabled local IPAM as a beta feature of the 2.6 release, you cannot use or delete these networks after you upgrade to 3.0. You must remove these networks before you upgrade to release 3.0.

Enabling Local IPAM

You must use local IPAM to use configurable virtual networks. On new 3.0 clusters created with Apcera Installer, local IPAM is the default configuration so no action is needed. However, if you are upgrading to release 3.0, you will need to enable it as follows:

  1. Set "enable_local_ipam" to true in cluster.conf by adding the following block:

     chef: {
       "continuum": {
         "enable_local_ipam": true,
       }
     }
    
  2. Redeploy the cluster.

  3. Create a new virtual network and test the switch to local IPAM.

    Assuming local IPAM is enabled, a new virtual network is assigned the default subnet pool address, for example: 10.224.0.0/12. Previously created virtual networks will have the address range 192.168.virtual_network_id.0/24.

Disabling local IPAM

You can disable local IPAM and revert to global IPAM as follows:

  1. Set "enable_local_ipam" to false in cluster.conf:

     chef: {
       "continuum": {
         "enable_local_ipam": false,
       }
     }
    
  2. Redeploy the cluster.

  3. Create a new virtual network and test global IPAM.

    Assuming local IPAM is disabled, a new virtual network is assigned the address range 192.168.virtual_network_id.0/24.