mdtest.go

package main

import (
	"fmt"

	"github.com/pkg/errors"
	"github.com/rancher/go-rancher-metadata/metadata"
)

func main() {
	mc := metadata.NewClient("http://rancher-metadata/latest")

	networks, _, err := localNetworks(mc)
	if err != nil {
		fmt.Printf("error fetching local networks %s\n", err.Error())
		panic("oh no")
	}

	for _, n := range networks {
		host, err := mc.GetSelfHost()
		if err != nil {
			fmt.Printf("error fetching self host from metadata %s\n", err.Error())
			panic("oh no")
		}

		containers, err := mc.GetContainers()
		if err != nil {
			fmt.Printf("error fetching containers from metadata: %s\n", err.Error())
			panic("oh no")
		}

		for _, aContainer := range containers {
			if !(aContainer.HostUUID == host.UUID &&
				aContainer.State == "running" &&
				aContainer.ExternalId != "" &&
				aContainer.PrimaryIp != "" &&
				aContainer.PrimaryMacAddress != "" &&
				aContainer.NetworkUUID == n.UUID) {
				continue
			}

			fmt.Printf("[!] Will modify %s\n", aContainer.Name)
		}
	}
}

func localNetworks(mc metadata.Client) ([]metadata.Network, map[string]metadata.Container, error) {
	networks, err := mc.GetNetworks()
	if err != nil {
		return nil, nil, errors.Wrap(err, "error fetching networks from metadata")
	}

	host, err := mc.GetSelfHost()
	if err != nil {
		return nil, nil, errors.Wrap(err, "error fetching self host from metadata")
	}

	services, err := mc.GetServices()
	if err != nil {
		return nil, nil, errors.Wrap(err, "error fetching services from metadata")
	}

	localNetworks := map[string]bool{}
	routers := map[string]metadata.Container{}
	for _, service := range services {
		// Trick to select the primary service of the network plugin
		// stack
		// TODO: Need to check if it's needed for Calico?
		if !(service.Kind == "networkDriverService" &&
			service.Name == service.PrimaryServiceName) {
			continue
		}

		for _, aContainer := range service.Containers {
			if aContainer.HostUUID == host.UUID {
				routers[aContainer.NetworkUUID] = aContainer
				localNetworks[aContainer.NetworkUUID] = true
			}
		}
	}

	if len(localNetworks) == 0 {
		return nil, nil, nil
	}

	ret := []metadata.Network{}
	for _, aNetwork := range networks {
		if _, ok := localNetworks[aNetwork.UUID]; ok {
			ret = append(ret, aNetwork)
		}
	}

	return ret, routers, nil
}