117 lines
3.1 KiB
Go
117 lines
3.1 KiB
Go
package main
|
|
|
|
import (
|
|
"fmt"
|
|
"net"
|
|
"strconv"
|
|
"syscall"
|
|
|
|
docker "github.com/fsouza/go-dockerclient"
|
|
"github.com/vishvananda/netns"
|
|
|
|
weavenet "github.com/weaveworks/weave/net"
|
|
)
|
|
|
|
func attach(args []string) error {
|
|
if len(args) < 4 {
|
|
cmdUsage("attach-container", "[--no-multicast-route] [--keep-tx-on] [--hairpin-mode=true|false] <container-id> <bridge-name> <mtu> <cidr>...")
|
|
}
|
|
|
|
keepTXOn := false
|
|
withMulticastRoute := true
|
|
hairpinMode := true
|
|
for i := 0; i < len(args); {
|
|
switch args[i] {
|
|
case "--no-multicast-route":
|
|
withMulticastRoute = false
|
|
args = append(args[:i], args[i+1:]...)
|
|
case "--keep-tx-on":
|
|
keepTXOn = true
|
|
args = append(args[:i], args[i+1:]...)
|
|
case "--hairpin-mode=false":
|
|
hairpinMode = false
|
|
args = append(args[:i], args[i+1:]...)
|
|
default:
|
|
i++
|
|
}
|
|
}
|
|
|
|
pid, err := containerPid(args[0])
|
|
if err != nil {
|
|
return err
|
|
}
|
|
nsContainer, err := netns.GetFromPid(pid)
|
|
if err != nil {
|
|
return fmt.Errorf("unable to open namespace for container %s: %s", args[0], err)
|
|
}
|
|
|
|
if nsHost, err := netns.GetFromPid(1); err != nil {
|
|
return fmt.Errorf("unable to open host namespace: %s", err)
|
|
} else if nsHost.Equal(nsContainer) {
|
|
return fmt.Errorf("Container is running in the host network namespace, and therefore cannot be\nconnected to weave - perhaps the container was started with --net=host")
|
|
}
|
|
mtu, err := strconv.Atoi(args[2])
|
|
if err != nil && args[3] != "" {
|
|
return fmt.Errorf("unable to parse mtu %q: %s", args[2], err)
|
|
}
|
|
cidrs, err := parseCIDRs(args[3:])
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
err = weavenet.AttachContainer(weavenet.NSPathByPid(pid), fmt.Sprint(pid), weavenet.VethName, args[1], mtu, withMulticastRoute, cidrs, keepTXOn, hairpinMode)
|
|
// If we detected an error but the container has died, tell the user that instead.
|
|
if err != nil && !processExists(pid) {
|
|
err = fmt.Errorf("Container %s died", args[0])
|
|
}
|
|
return err
|
|
}
|
|
|
|
func containerPid(containerID string) (int, error) {
|
|
c, err := docker.NewVersionedClientFromEnv("1.18")
|
|
if err != nil {
|
|
return 0, fmt.Errorf("unable to connect to docker: %s", err)
|
|
}
|
|
container, err := c.InspectContainer(containerID)
|
|
if err != nil {
|
|
return 0, fmt.Errorf("unable to inspect container %s: %s", containerID, err)
|
|
}
|
|
if container.State.Pid == 0 {
|
|
return 0, fmt.Errorf("container %s not running", containerID)
|
|
}
|
|
return container.State.Pid, nil
|
|
}
|
|
|
|
func processExists(pid int) bool {
|
|
err := syscall.Kill(pid, syscall.Signal(0))
|
|
return err == nil || err == syscall.EPERM
|
|
}
|
|
|
|
func parseCIDRs(args []string) (cidrs []*net.IPNet, err error) {
|
|
for _, ipstr := range args {
|
|
ip, ipnet, err := net.ParseCIDR(ipstr)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
ipnet.IP = ip // we want the specific IP plus the mask
|
|
cidrs = append(cidrs, ipnet)
|
|
}
|
|
return
|
|
}
|
|
|
|
func detach(args []string) error {
|
|
if len(args) < 2 {
|
|
cmdUsage("detach-container", "<container-id> <cidr>...")
|
|
}
|
|
|
|
pid, err := containerPid(args[0])
|
|
if err != nil {
|
|
return err
|
|
}
|
|
cidrs, err := parseCIDRs(args[1:])
|
|
if err != nil {
|
|
return err
|
|
}
|
|
return weavenet.DetachContainer(weavenet.NSPathByPid(pid), args[0], weavenet.VethName, cidrs)
|
|
}
|