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go-cni

A generic CNI library to provide APIs for CNI plugin interactions. The library provides APIs to:

  • Load CNI network config from different sources
  • Setup networks for container namespace
  • Remove networks from container namespace
  • Query status of CNI network plugin initialization

go-cni aims to support plugins that implement Container Network Interface

Usage

package main

import (
    "context"
    "fmt"
    "log"

    gocni "github.com/containerd/go-cni"
)

func main() {
    id := "example"
    netns := "/var/run/netns/example-ns-1"

    // CNI allows multiple CNI configurations and the network interface
    // will be named by eth0, eth1, ..., ethN.
    ifPrefixName := "eth"
    defaultIfName := "eth0"

    // Initializes library
    l, err := gocni.New(
        // one for loopback network interface
        gocni.WithMinNetworkCount(2),
        gocni.WithPluginConfDir("/etc/cni/net.d"),
        gocni.WithPluginDir([]string{"/opt/cni/bin"}),
        // Sets the prefix for network interfaces, eth by default
        gocni.WithInterfacePrefix(ifPrefixName))
    if err != nil {
        log.Fatalf("failed to initialize cni library: %v", err)
    }

    // Load the cni configuration
    if err := l.Load(gocni.WithLoNetwork, gocni.WithDefaultConf); err != nil {
        log.Fatalf("failed to load cni configuration: %v", err)
    }

    // Setup network for namespace.
    labels := map[string]string{
        "K8S_POD_NAMESPACE":          "namespace1",
        "K8S_POD_NAME":               "pod1",
        "K8S_POD_INFRA_CONTAINER_ID": id,
        // Plugin tolerates all Args embedded by unknown labels, like
        // K8S_POD_NAMESPACE/NAME/INFRA_CONTAINER_ID...
        "IgnoreUnknown": "1",
    }

    ctx := context.Background()

    // Teardown network
    defer func() {
        if err := l.Remove(ctx, id, netns, gocni.WithLabels(labels)); err != nil {
            log.Fatalf("failed to teardown network: %v", err)
        }
    }()

    // Setup network
    result, err := l.Setup(ctx, id, netns, gocni.WithLabels(labels))
    if err != nil {
        log.Fatalf("failed to setup network for namespace: %v", err)
    }

    // Get IP of the default interface
    IP := result.Interfaces[defaultIfName].IPConfigs[0].IP.String()
    fmt.Printf("IP of the default interface %s:%s", defaultIfName, IP)
}

Project details

The go-cni is a containerd sub-project, licensed under the Apache 2.0 license. As a containerd sub-project, you will find the:

information in our containerd/project repository.

Go Cni

A generic CNI library to provide APIs for CNI plugin interactions

Go Cni Info

⭐ Stars 74
🔗 Source Code github.com
🕒 Last Update a year ago
🕒 Created 4 years ago
🐞 Open Issues 7
➗ Star-Issue Ratio 11
😎 Author containerd