Docker CNI

This repo aims to integrate CNI with Dockerd.

There is, according to CNI repo, an approach to integrate by running a pause equivalent container ahead of the application container, but that's too pod-like for those who resent pod models.

Let's figure out yet another solution.

Usage

0. Prepare your CNI plugin

Make sure you have everything ready:

1. CNI binaries in the right place: for example, /opt/cni/bin/calico and /opt/cni/bin/calico-ipam binaries
2. CNI configures in the right place: for exmaple, /etc/cni/net.d/10-calico.conf
3. Other services needed: for example, calico-node container

Notes:

1. Provided there are multiple CNI configures in the dir, docker-cni will only use the first config in alphabet order.

1. Configure docker-cni

1.1 install docker-cni binary

Download the latest binary from release.

1.2 docker-cni configuration

mkdir -p /etc/docker/
cat <<! >/etc/docker/cni.yaml
oci_bin: /usr/bin/runc
cni_conf_dir: /etc/cni/net.d/
cni_bin_dir: /opt/cni/bin/
cni_ifname: eth0
cni_log: /var/log/cni.log
log_driver: file:///var/log/docker-cni.log
log_level: debug
!

You may revise the aforementioned configure with YOUR cni_conf_dir and cni_bin_dir.

2. Configure dockerd

2.1 dockerd daemon configuration

Add the additional runtime in docker daemon configure, which is usually located at /etc/docker/daemon.json:

{
    ...
    "runtimes": {
        "cni": {
            "path": "/usr/local/bin/docker-cni",
            "runtimeArgs": [ "oci", "--config", "/etc/docker/cni.yaml", "--" ]
        }
    }
}

2.2 restart dockerd

systemctl restart docker

3. Create docker container with CNI

docker run -td --runtime cni --net none bash bash

That's everything.