spiegel_podman/cmd/podman/pods/create.go
Stefano Brivio aa47e05ae4 libpod: Add pasta networking mode
Conceptually equivalent to networking by means of slirp4netns(1),
with a few practical differences:

- pasta(1) forks to background once networking is configured in the
  namespace and quits on its own once the namespace is deleted:
  file descriptor synchronisation and PID tracking are not needed

- port forwarding is configured via command line options at start-up,
  instead of an API socket: this is taken care of right away as we're
  about to start pasta

- there's no need for further selection of port forwarding modes:
  pasta behaves similarly to containers-rootlessport for local binds
  (splice() instead of read()/write() pairs, without L2-L4
  translation), and keeps the original source address for non-local
  connections like slirp4netns does

- IPv6 is not an experimental feature, and enabled by default. IPv6
  port forwarding is supported

- by default, addresses and routes are copied from the host, that is,
  container users will see the same IP address and routes as if they
  were in the init namespace context. The interface name is also
  sourced from the host upstream interface with the first default
  route in the routing table. This is also configurable as documented

- sandboxing and seccomp(2) policies cannot be disabled

- only rootless mode is supported.

See https://passt.top for more details about pasta.

Also add a link to the maintained build of pasta(1) manual as valid
in the man page cross-reference checks: that's where the man page
for the latest build actually is -- it's not on Github and it doesn't
match any existing pattern, so add it explicitly.

Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
2022-11-08 00:16:35 +01:00

312 lines
9.6 KiB
Go

package pods
import (
"context"
"errors"
"fmt"
"os"
"runtime"
"sort"
"strconv"
"strings"
"github.com/containers/common/pkg/completion"
"github.com/containers/common/pkg/sysinfo"
"github.com/containers/podman/v4/cmd/podman/common"
"github.com/containers/podman/v4/cmd/podman/containers"
"github.com/containers/podman/v4/cmd/podman/parse"
"github.com/containers/podman/v4/cmd/podman/registry"
"github.com/containers/podman/v4/cmd/podman/utils"
"github.com/containers/podman/v4/libpod/define"
"github.com/containers/podman/v4/pkg/domain/entities"
"github.com/containers/podman/v4/pkg/specgen"
"github.com/containers/podman/v4/pkg/specgenutil"
"github.com/containers/podman/v4/pkg/util"
"github.com/docker/docker/pkg/parsers"
"github.com/sirupsen/logrus"
"github.com/spf13/cobra"
)
var (
podCreateDescription = `After creating the pod, the pod ID is printed to stdout.
You can then start it at any time with the podman pod start <pod_id> command. The pod will be created with the initial state 'created'.`
createCommand = &cobra.Command{
Use: "create [options] [NAME]",
Args: cobra.MaximumNArgs(1),
Short: "Create a new empty pod",
Long: podCreateDescription,
RunE: create,
ValidArgsFunction: completion.AutocompleteNone,
Example: `podman pod create
podman pod create --label foo=bar mypod`,
}
)
var (
createOptions entities.PodCreateOptions
infraOptions = entities.NewInfraContainerCreateOptions()
infraImage string
labels, labelFile []string
podIDFile string
replace bool
share string
shareParent bool
)
func init() {
registry.Commands = append(registry.Commands, registry.CliCommand{
Command: createCommand,
Parent: podCmd,
})
flags := createCommand.Flags()
flags.SetInterspersed(false)
common.DefineCreateDefaults(&infraOptions)
common.DefineCreateFlags(createCommand, &infraOptions, entities.InfraMode)
common.DefineNetFlags(createCommand)
flags.BoolVar(&createOptions.Infra, "infra", true, "Create an infra container associated with the pod to share namespaces with")
nameFlagName := "name"
flags.StringVarP(&createOptions.Name, nameFlagName, "n", "", "Assign a name to the pod")
_ = createCommand.RegisterFlagCompletionFunc(nameFlagName, completion.AutocompleteNone)
policyFlag := "exit-policy"
flags.StringVarP(&createOptions.ExitPolicy, policyFlag, "", string(containerConfig.Engine.PodExitPolicy), "Behaviour when the last container exits")
_ = createCommand.RegisterFlagCompletionFunc(policyFlag, common.AutocompletePodExitPolicy)
infraImageFlagName := "infra-image"
var defInfraImage string
if !registry.IsRemote() {
defInfraImage = containerConfig.Engine.InfraImage
}
flags.StringVar(&infraImage, infraImageFlagName, defInfraImage, "Image to use to override builtin infra container")
_ = createCommand.RegisterFlagCompletionFunc(infraImageFlagName, common.AutocompleteImages)
podIDFileFlagName := "pod-id-file"
flags.StringVar(&podIDFile, podIDFileFlagName, "", "Write the pod ID to the file")
_ = createCommand.RegisterFlagCompletionFunc(podIDFileFlagName, completion.AutocompleteDefault)
flags.BoolVar(&replace, "replace", false, "If a pod with the same name exists, replace it")
shareFlagName := "share"
flags.StringVar(&share, shareFlagName, specgen.DefaultKernelNamespaces, "A comma delimited list of kernel namespaces the pod will share")
_ = createCommand.RegisterFlagCompletionFunc(shareFlagName, common.AutocompletePodShareNamespace)
shareParentFlagName := "share-parent"
flags.BoolVar(&shareParent, shareParentFlagName, true, "Set the pod's cgroup as the cgroup parent for all containers joining the pod")
flags.SetNormalizeFunc(utils.AliasFlags)
}
func create(cmd *cobra.Command, args []string) error {
var (
err error
imageName string
rawImageName string
podName string
)
if len(args) > 0 {
if len(createOptions.Name) > 0 {
return fmt.Errorf("cannot specify --name and NAME at the same time")
}
createOptions.Name = args[0]
}
labelFile = infraOptions.LabelFile
labels = infraOptions.Label
createOptions.Labels, err = parse.GetAllLabels(labelFile, labels)
if err != nil {
return fmt.Errorf("unable to process labels: %w", err)
}
if cmd.Flag("infra-image").Changed {
imageName = infraImage
}
img := imageName
if !cmd.Flag("infra").Changed && (share == "none" || share == "") {
// we do not want an infra container when not sharing namespaces
createOptions.Infra = false
}
report, err := registry.ContainerEngine().NetworkExists(registry.Context(), "pasta")
if err != nil {
return err
}
pastaNetworkNameExists := report.Value
if !createOptions.Infra {
if cmd.Flag("no-hosts").Changed {
return fmt.Errorf("cannot specify --no-hosts without an infra container")
}
flags := cmd.Flags()
createOptions.Net, err = common.NetFlagsToNetOptions(nil, *flags, pastaNetworkNameExists)
if err != nil {
return err
}
logrus.Debugf("Not creating an infra container")
createOptions.InfraImage = ""
if createOptions.InfraName != "" {
return errors.New("cannot set infra-name without an infra container")
}
if cmd.Flag("share").Changed && share != "none" && share != "" {
return fmt.Errorf("cannot set share(%s) namespaces without an infra container", cmd.Flag("share").Value)
}
createOptions.Share = nil
} else {
// reassign certain options for lbpod api, these need to be populated in spec
flags := cmd.Flags()
infraOptions.Net, err = common.NetFlagsToNetOptions(nil, *flags, pastaNetworkNameExists)
if err != nil {
return err
}
infraOptions, err = containers.CreateInit(cmd, infraOptions, true)
if err != nil {
return err
}
if strings.Contains(share, "cgroup") && shareParent {
return fmt.Errorf("cannot define the pod as the cgroup parent at the same time as joining the infra container's cgroupNS: %w", define.ErrInvalidArg)
}
if strings.HasPrefix(share, "+") {
createOptions.Share = append(createOptions.Share, strings.Split(specgen.DefaultKernelNamespaces, ",")...)
share = share[1:]
}
createOptions.Share = append(createOptions.Share, strings.Split(share, ",")...)
createOptions.ShareParent = &shareParent
if cmd.Flag("infra-command").Changed {
// Only send content to server side if user changed defaults
cmdIn, err := cmd.Flags().GetString("infra-command")
infraOptions.Entrypoint = &cmdIn
if err != nil {
return err
}
}
podName = createOptions.Name
err = common.ContainerToPodOptions(&infraOptions, &createOptions)
if err != nil {
return err
}
createOptions.Name = podName
}
if len(createOptions.Net.PublishPorts) > 0 {
if !createOptions.Infra {
return fmt.Errorf("you must have an infra container to publish port bindings to the host")
}
}
createOptions.CreateCommand = os.Args
if replace {
if err := replacePod(createOptions.Name); err != nil {
return err
}
}
numCPU := sysinfo.NumCPU()
if numCPU == 0 {
numCPU = runtime.NumCPU()
}
if createOptions.Cpus > float64(numCPU) {
createOptions.Cpus = float64(numCPU)
}
copy := infraOptions.CPUSetCPUs
cpuSet := infraOptions.CPUS
if cpuSet == 0 {
cpuSet = float64(sysinfo.NumCPU())
}
ret, err := parsers.ParseUintList(copy)
copy = ""
if err != nil {
return fmt.Errorf("could not parse list: %w", err)
}
var vals []int
for ind, val := range ret {
if val {
vals = append(vals, ind)
}
}
sort.Ints(vals)
for ind, core := range vals {
switch {
case core > int(cpuSet):
if copy == "" {
copy = "0-" + strconv.Itoa(int(cpuSet))
infraOptions.CPUSetCPUs = copy
break
} else {
infraOptions.CPUSetCPUs = copy
break
}
case ind != 0:
copy += "," + strconv.Itoa(core)
default:
copy = "" + strconv.Itoa(core)
}
}
createOptions.Cpus = infraOptions.CPUS
createOptions.CpusetCpus = infraOptions.CPUSetCPUs
podSpec := specgen.NewPodSpecGenerator()
podSpec, err = entities.ToPodSpecGen(*podSpec, &createOptions)
if err != nil {
return err
}
if createOptions.Infra {
rawImageName = img
podSpec.InfraImage = imageName
if infraOptions.Entrypoint != nil {
createOptions.InfraCommand = infraOptions.Entrypoint
}
podSpec.InfraContainerSpec = specgen.NewSpecGenerator(imageName, false)
podSpec.InfraContainerSpec.RawImageName = rawImageName
podSpec.InfraContainerSpec.NetworkOptions = podSpec.NetworkOptions
err = specgenutil.FillOutSpecGen(podSpec.InfraContainerSpec, &infraOptions, []string{})
if err != nil {
return err
}
podSpec.Volumes = podSpec.InfraContainerSpec.Volumes
podSpec.ImageVolumes = podSpec.InfraContainerSpec.ImageVolumes
podSpec.OverlayVolumes = podSpec.InfraContainerSpec.OverlayVolumes
podSpec.Mounts = podSpec.InfraContainerSpec.Mounts
// Marshall and Unmarshal the spec in order to map similar entities
wrapped, err := json.Marshal(podSpec.InfraContainerSpec)
if err != nil {
return err
}
err = json.Unmarshal(wrapped, podSpec)
if err != nil {
return err
}
podSpec.Name = podName
}
PodSpec := entities.PodSpec{PodSpecGen: *podSpec}
response, err := registry.ContainerEngine().PodCreate(context.Background(), PodSpec)
if err != nil {
return err
}
if len(podIDFile) > 0 {
if err := util.CreateIDFile(podIDFile, response.Id); err != nil {
return fmt.Errorf("failed to write pod ID to file: %w", err)
}
}
fmt.Println(response.Id)
return nil
}
func replacePod(name string) error {
if len(name) == 0 {
return errors.New("cannot replace pod without --name being set")
}
rmOptions := entities.PodRmOptions{
Force: true, // stop and remove pod
Ignore: true, // ignore if pod doesn't exist
}
errs := removePods([]string{name}, rmOptions, false)
return errs.PrintErrors()
}