1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
|
[](https://travis-ci.org/containernetworking/cni)
[](https://coveralls.io/github/containernetworking/cni?branch=master)
[](https://cryptic-tundra-43194.herokuapp.com/)
---
# Community Sync Meeting
There is a community sync meeting for users and developers every 1-2 months. The next meeting will help on a Google Hangout and the link is in the [agenda](https://docs.google.com/document/d/10ECyT2mBGewsJUcmYmS8QNo1AcNgy2ZIe2xS7lShYhE/edit?usp=sharing) (Notes from previous meeting are also in this doc). The next meeting will be held on *Wednesday, June 21th* at *3:00pm UTC* [Add to Calendar]https://www.worldtimebuddy.com/?qm=1&lid=100,5,2643743,5391959&h=100&date=2017-6-21&sln=15-16).
---
# CNI - the Container Network Interface
## What is CNI?
CNI (_Container Network Interface_), a [Cloud Native Computing Foundation](https://cncf.io) project, consists of a specification and libraries for writing plugins to configure network interfaces in Linux containers, along with a number of supported plugins.
CNI concerns itself only with network connectivity of containers and removing allocated resources when the container is deleted.
Because of this focus, CNI has a wide range of support and the specification is simple to implement.
As well as the [specification](SPEC.md), this repository contains the Go source code of a [library for integrating CNI into applications](libcni) and an [example command-line tool](cnitool) for executing CNI plugins. A [separate repository contains reference plugins](https://github.com/containernetworking/plugins) and a template for making new plugins.
The template code makes it straight-forward to create a CNI plugin for an existing container networking project.
CNI also makes a good framework for creating a new container networking project from scratch.
## Why develop CNI?
Application containers on Linux are a rapidly evolving area, and within this area networking is not well addressed as it is highly environment-specific.
We believe that many container runtimes and orchestrators will seek to solve the same problem of making the network layer pluggable.
To avoid duplication, we think it is prudent to define a common interface between the network plugins and container execution: hence we put forward this specification, along with libraries for Go and a set of plugins.
## Who is using CNI?
### Container runtimes
- [rkt - container engine](https://coreos.com/blog/rkt-cni-networking.html)
- [Kurma - container runtime](http://kurma.io/)
- [Kubernetes - a system to simplify container operations](http://kubernetes.io/docs/admin/network-plugins/)
- [OpenShift - Kubernetes with additional enterprise features](https://github.com/openshift/origin/blob/master/docs/openshift_networking_requirements.md)
- [Cloud Foundry - a platform for cloud applications](https://github.com/cloudfoundry-incubator/cf-networking-release)
- [Mesos - a distributed systems kernel](https://github.com/apache/mesos/blob/master/docs/cni.md)
### 3rd party plugins
- [Project Calico - a layer 3 virtual network](https://github.com/projectcalico/calico-cni)
- [Weave - a multi-host Docker network](https://github.com/weaveworks/weave)
- [Contiv Networking - policy networking for various use cases](https://github.com/contiv/netplugin)
- [SR-IOV](https://github.com/hustcat/sriov-cni)
- [Cilium - BPF & XDP for containers](https://github.com/cilium/cilium)
- [Infoblox - enterprise IP address management for containers](https://github.com/infobloxopen/cni-infoblox)
- [Multus - a Multi plugin](https://github.com/Intel-Corp/multus-cni)
- [Romana - Layer 3 CNI plugin supporting network policy for Kubernetes](https://github.com/romana/kube)
- [CNI-Genie - generic CNI network plugin](https://github.com/Huawei-PaaS/CNI-Genie)
- [Nuage CNI - Nuage Networks SDN plugin for network policy kubernetes support ](https://github.com/nuagenetworks/nuage-cni)
- [Silk - a CNI plugin designed for Cloud Foundry](https://github.com/cloudfoundry-incubator/silk)
- [Linen - a CNI plugin designed for overlay networks with Open vSwitch and fit in SDN/OpenFlow network environment](https://github.com/John-Lin/linen-cni)
The CNI team also maintains some [core plugins in a separate repository](https://github.com/containernetworking/plugins).
## Contributing to CNI
We welcome contributions, including [bug reports](https://github.com/containernetworking/cni/issues), and code and documentation improvements.
If you intend to contribute to code or documentation, please read [CONTRIBUTING.md](CONTRIBUTING.md). Also see the [contact section](#contact) in this README.
## How do I use CNI?
### Requirements
The CNI spec is language agnostic. To use the Go language libraries in this repository, you'll need a recent version of Go. Our [automated tests](https://travis-ci.org/containernetworking/cni/builds) cover Go versions 1.7 and 1.8.
### Reference Plugins
The CNI project maintains a set of [reference plugins](https://github.com/containernetworking/plugins) that implement the CNI specification.
NOTE: the reference plugins used to live in this repository but have been split out into a [separate repository](https://github.com/containernetworking/plugins) as of May 2017.
### Running the plugins
After building and installing the [reference plugins](https://github.com/containernetworking/plugins), you can use the `priv-net-run.sh` and `docker-run.sh` scripts in the `scripts/` directory to exercise the plugins.
**note - priv-net-run.sh depends on `jq`**
Start out by creating a netconf file to describe a network:
```bash
$ mkdir -p /etc/cni/net.d
$ cat >/etc/cni/net.d/10-mynet.conf <<EOF
{
"cniVersion": "0.2.0",
"name": "mynet",
"type": "bridge",
"bridge": "cni0",
"isGateway": true,
"ipMasq": true,
"ipam": {
"type": "host-local",
"subnet": "10.22.0.0/16",
"routes": [
{ "dst": "0.0.0.0/0" }
]
}
}
EOF
$ cat >/etc/cni/net.d/99-loopback.conf <<EOF
{
"cniVersion": "0.2.0",
"type": "loopback"
}
EOF
```
The directory `/etc/cni/net.d` is the default location in which the scripts will look for net configurations.
Next, build the plugins:
```bash
$ cd $GOPATH/src/github.com/containernetworking/plugins
$ ./build.sh
```
Finally, execute a command (`ifconfig` in this example) in a private network namespace that has joined the `mynet` network:
```bash
$ CNI_PATH=$GOPATH/src/github.com/containernetworking/plugins/bin
$ cd $GOPATH/src/github.com/containernetworking/cni/scripts
$ sudo CNI_PATH=$CNI_PATH ./priv-net-run.sh ifconfig
eth0 Link encap:Ethernet HWaddr f2:c2:6f:54:b8:2b
inet addr:10.22.0.2 Bcast:0.0.0.0 Mask:255.255.0.0
inet6 addr: fe80::f0c2:6fff:fe54:b82b/64 Scope:Link
UP BROADCAST MULTICAST MTU:1500 Metric:1
RX packets:1 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:1 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:90 (90.0 B) TX bytes:0 (0.0 B)
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:65536 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)
```
The environment variable `CNI_PATH` tells the scripts and library where to look for plugin executables.
## Running a Docker container with network namespace set up by CNI plugins
Use the instructions in the previous section to define a netconf and build the plugins.
Next, docker-run.sh script wraps `docker run`, to execute the plugins prior to entering the container:
```bash
$ CNI_PATH=$GOPATH/src/github.com/containernetworking/plugins/bin
$ cd $GOPATH/src/github.com/containernetworking/cni/scripts
$ sudo CNI_PATH=$CNI_PATH ./docker-run.sh --rm busybox:latest ifconfig
eth0 Link encap:Ethernet HWaddr fa:60:70:aa:07:d1
inet addr:10.22.0.2 Bcast:0.0.0.0 Mask:255.255.0.0
inet6 addr: fe80::f860:70ff:feaa:7d1/64 Scope:Link
UP BROADCAST MULTICAST MTU:1500 Metric:1
RX packets:1 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:1 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:90 (90.0 B) TX bytes:0 (0.0 B)
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:65536 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)
```
## What might CNI do in the future?
CNI currently covers a wide range of needs for network configuration due to it simple model and API.
However, in the future CNI might want to branch out into other directions:
- Dynamic updates to existing network configuration
- Dynamic policies for network bandwidth and firewall rules
If these topics of are interest, please contact the team via the mailing list or IRC and find some like-minded people in the community to put a proposal together.
## Contact
For any questions about CNI, please reach out on the mailing list:
- Email: [cni-dev](https://groups.google.com/forum/#!forum/cni-dev)
- IRC: #[containernetworking](irc://irc.freenode.org:6667/#containernetworking) channel on freenode.org
- Slack: [containernetworking.slack.com](https://cryptic-tundra-43194.herokuapp.com)
|
