{"id":2524,"date":"2016-10-04T05:00:41","date_gmt":"2016-10-04T05:00:41","guid":{"rendered":"https:\/\/live-infoblox-blog.pantheonsite.io\/?p=2524"},"modified":"2022-10-20T14:34:42","modified_gmt":"2022-10-20T21:34:42","slug":"cni-networking-and-ipam","status":"publish","type":"post","link":"https:\/\/www.infoblox.com\/blog\/community\/cni-networking-and-ipam\/","title":{"rendered":"CNI Networking and IPAM"},"content":{"rendered":"

There’s a heightened interest in\u00a0Docker networking<\/a>\u00a0and IPAM content, so we\u2019re going to look at rkt\/CNI and how\u00a0Infoblox<\/a>\u00a0can also be leveraged to provide centralized IPAM functions in a multi-host environment.<\/p>\n

Like Docker, rkt is an open-source project that provides a runtime environment for deploying software applications in the form of containers (https:\/\/coreos.com\/rkt<\/a>). In the case of rkt, the networking of containers is provided by Container Networking Interface (CNI) (https:\/\/github.com\/containernetworking\/cni\/blob\/master\/README.md<\/a>).<\/p>\n

In this blog, I am going to take you through a typical deployment use case for Rkt\/CNI. But, before we do that, I\u2019m going to provide some background on rkt and CNI.<\/p>\n

Background<\/h2>\n

rkt (or,\u00a0Rocket<\/i>, as it is originally called) is started as part of the CoreOS project which implements a container runtime environment conforming to the\u00a0App Container\u00a0<\/i>(appc<\/i>) as well as the\u00a0Application Container Image\u00a0<\/i>(ACI<\/i>) specifications. This is in support of the\u00a0Open Container Initiative<\/i>\u00a0to define a vendor and operating system neutral containerization standard.<\/p>\n

As for CNI, it is the generic plugin-based networking layer for supporting container runtime environments, of which\u00a0rkt<\/i>\u00a0is one. Indeed, the design of CNI is initially derived from the rkt Networking Proposal.<\/p>\n

In CNI, a network is a group of entities that are uniquely addressable that can communicate with each other. An entity could be a container, a host or a network device. In this blog, we\u2019ll be focusing on\u00a0rkt\u00a0<\/i>containers, which can be added or removed from one or more networks as they are being launched and deleted by\u00a0rkt.<\/i><\/p>\n

CNI Network Configuration<\/h2>\n

In CNI, the configuration of a network is defined using a JSON formatted configuration file. In addition to\u00a0well-known<\/i>\u00a0fields, it also includes optional fields as well as plugin specific fields. Here\u2019s an example network configuration file:<\/p>\n

\"infoblox-container.jpg\"<\/i><\/span><\/p>\n

Figure 1: Example Network Configuration File<\/i><\/p>\n

For a complete description of all the configuration fields, refer to:\u00a0https:\/\/github.com\/containernetworking\/cni\/blob\/master\/SPEC.md#network-configuration<\/a><\/p>\n

In the meantime, let\u2019s look at the fields included in the example above.<\/p>\n