containerd/pkg/cri/sbserver/sandbox_run.go

/*
   Copyright The containerd Authors.

   Licensed under the Apache License, Version 2.0 (the "License");
   you may not use this file except in compliance with the License.
   You may obtain a copy of the License at

       http://www.apache.org/licenses/LICENSE-2.0

   Unless required by applicable law or agreed to in writing, software
   distributed under the License is distributed on an "AS IS" BASIS,
   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   See the License for the specific language governing permissions and
   limitations under the License.
*/

package sbserver

import (
	"context"
	"encoding/json"
	"errors"
	"fmt"
	"math"
	"path/filepath"
	goruntime "runtime"
	"strings"
	"time"

	eventtypes "github.com/containerd/containerd/api/events"
	"github.com/containerd/containerd/protobuf"
	sb "github.com/containerd/containerd/sandbox"
	"github.com/containerd/go-cni"
	"github.com/containerd/typeurl"
	"github.com/sirupsen/logrus"
	runtime "k8s.io/cri-api/pkg/apis/runtime/v1"

	"github.com/containerd/containerd/log"
	"github.com/containerd/containerd/pkg/cri/annotations"
	criconfig "github.com/containerd/containerd/pkg/cri/config"
	"github.com/containerd/containerd/pkg/cri/server/bandwidth"
	sandboxstore "github.com/containerd/containerd/pkg/cri/store/sandbox"
	"github.com/containerd/containerd/pkg/cri/util"
	ctrdutil "github.com/containerd/containerd/pkg/cri/util"
	"github.com/containerd/containerd/pkg/netns"
)

func init() {
	typeurl.Register(&sandboxstore.Metadata{},
		"github.com/containerd/cri/pkg/store/sandbox", "Metadata")
}

// RunPodSandbox creates and starts a pod-level sandbox. Runtimes should ensure
// the sandbox is in ready state.
func (c *criService) RunPodSandbox(ctx context.Context, r *runtime.RunPodSandboxRequest) (_ *runtime.RunPodSandboxResponse, retErr error) {
	config := r.GetConfig()
	log.G(ctx).Debugf("Sandbox config %+v", config)

	// Generate unique id and name for the sandbox and reserve the name.
	id := util.GenerateID()
	metadata := config.GetMetadata()
	if metadata == nil {
		return nil, errors.New("sandbox config must include metadata")
	}
	name := makeSandboxName(metadata)
	log.G(ctx).WithField("podsandboxid", id).Debugf("generated id for sandbox name %q", name)
	// Reserve the sandbox name to avoid concurrent `RunPodSandbox` request starting the
	// same sandbox.
	if err := c.sandboxNameIndex.Reserve(name, id); err != nil {
		return nil, fmt.Errorf("failed to reserve sandbox name %q: %w", name, err)
	}
	defer func() {
		// Release the name if the function returns with an error.
		if retErr != nil {
			c.sandboxNameIndex.ReleaseByName(name)
		}
	}()

	sandboxInfo := sb.Sandbox{
		ID: id,
		// TODO: runtime handler can be an empty string, should use default one and enable back validation of this field in metadata store.
		Runtime: sb.RuntimeOpts{Name: r.GetRuntimeHandler()},
	}

	// Save sandbox name
	sandboxInfo.AddLabel("name", name)

	// Create initial internal sandbox object.
	sandbox := sandboxstore.NewSandbox(
		sandboxstore.Metadata{
			ID:             id,
			Name:           name,
			Config:         config,
			RuntimeHandler: r.GetRuntimeHandler(),
		},
		sandboxstore.Status{
			State: sandboxstore.StateUnknown,
		},
	)

	var (
		podNetwork = true
		err        error
	)

	if goruntime.GOOS != "windows" &&
		config.GetLinux().GetSecurityContext().GetNamespaceOptions().GetNetwork() == runtime.NamespaceMode_NODE {
		// Pod network is not needed on linux with host network.
		podNetwork = false
	}
	if goruntime.GOOS == "windows" &&
		config.GetWindows().GetSecurityContext().GetHostProcess() {
		//Windows HostProcess pods can only run on the host network
		podNetwork = false
	}

	if podNetwork {
		netStart := time.Now()
		// If it is not in host network namespace then create a namespace and set the sandbox
		// handle. NetNSPath in sandbox metadata and NetNS is non empty only for non host network
		// namespaces. If the pod is in host network namespace then both are empty and should not
		// be used.
		var netnsMountDir = "/var/run/netns"
		if c.config.NetNSMountsUnderStateDir {
			netnsMountDir = filepath.Join(c.config.StateDir, "netns")
		}
		sandbox.NetNS, err = netns.NewNetNS(netnsMountDir)
		if err != nil {
			return nil, fmt.Errorf("failed to create network namespace for sandbox %q: %w", id, err)
		}
		sandbox.NetNSPath = sandbox.NetNS.GetPath()
		defer func() {
			if retErr != nil {
				deferCtx, deferCancel := ctrdutil.DeferContext()
				defer deferCancel()
				// Teardown network if an error is returned.
				if err := c.teardownPodNetwork(deferCtx, sandbox); err != nil {
					log.G(ctx).WithError(err).Errorf("Failed to destroy network for sandbox %q", id)
				}

				if err := sandbox.NetNS.Remove(); err != nil {
					log.G(ctx).WithError(err).Errorf("Failed to remove network namespace %s for sandbox %q", sandbox.NetNSPath, id)
				}
				sandbox.NetNSPath = ""
			}
		}()

		// Setup network for sandbox.
		// Certain VM based solutions like clear containers (Issue containerd/cri-containerd#524)
		// rely on the assumption that CRI shim will not be querying the network namespace to check the
		// network states such as IP.
		// In future runtime implementation should avoid relying on CRI shim implementation details.
		// In this case however caching the IP will add a subtle performance enhancement by avoiding
		// calls to network namespace of the pod to query the IP of the veth interface on every
		// SandboxStatus request.
		if err := c.setupPodNetwork(ctx, &sandbox); err != nil {
			return nil, fmt.Errorf("failed to setup network for sandbox %q: %w", id, err)
		}
		sandboxCreateNetworkTimer.UpdateSince(netStart)
	}

	// Save sandbox metadata to store
	if err := sandboxInfo.AddExtension("metadata", &sandbox.Metadata); err != nil {
		return nil, fmt.Errorf("unable to save sandbox %q to store: %w", id, err)
	}

	controller, err := c.getSandboxController(config, r.GetRuntimeHandler())
	if err != nil {
		return nil, fmt.Errorf("failed to get sandbox controller: %w", err)
	}

	if _, err := c.client.SandboxStore().Create(ctx, sandboxInfo); err != nil {
		return nil, fmt.Errorf("failed to save sandbox metadata: %w", err)
	}

	runtimeStart := time.Now()

	if err := controller.Create(ctx, id); err != nil {
		return nil, fmt.Errorf("failed to create sandbox %q: %w", id, err)
	}

	resp, err := controller.Start(ctx, id)
	if err != nil {
		return nil, fmt.Errorf("failed to start sandbox %q: %w", id, err)
	}

	labels := resp.GetLabels()
	if labels == nil {
		labels = map[string]string{}
	}

	sandbox.ProcessLabel = labels["selinux_label"]

	if err := sandbox.Status.Update(func(status sandboxstore.Status) (sandboxstore.Status, error) {
		// Set the pod sandbox as ready after successfully start sandbox container.
		status.Pid = resp.Pid
		status.State = sandboxstore.StateReady
		status.CreatedAt = protobuf.FromTimestamp(resp.CreatedAt)
		return status, nil
	}); err != nil {
		return nil, fmt.Errorf("failed to update sandbox status: %w", err)
	}

	// TODO: get rid of this. sandbox object should no longer have Container field.
	container, err := c.client.LoadContainer(ctx, id)
	if err != nil {
		return nil, fmt.Errorf("failed to load container %q for sandbox: %w", id, err)
	}
	// Add sandbox into sandbox store in INIT state.
	sandbox.Container = container

	if err := c.sandboxStore.Add(sandbox); err != nil {
		return nil, fmt.Errorf("failed to add sandbox %+v into store: %w", sandbox, err)
	}

	// start the monitor after adding sandbox into the store, this ensures
	// that sandbox is in the store, when event monitor receives the TaskExit event.
	//
	// TaskOOM from containerd may come before sandbox is added to store,
	// but we don't care about sandbox TaskOOM right now, so it is fine.
	go func() {
		resp, err := controller.Wait(context.Background(), id)
		if err != nil && err != context.Canceled && err != context.DeadlineExceeded {
			e := &eventtypes.TaskExit{
				ContainerID: id,
				ID:          id,
				// Pid is not used
				Pid:        0,
				ExitStatus: resp.ExitStatus,
				ExitedAt:   resp.ExitedAt,
			}
			c.eventMonitor.backOff.enBackOff(id, e)
		}
	}()

	sandboxRuntimeCreateTimer.WithValues(labels["oci_runtime_type"]).UpdateSince(runtimeStart)

	return &runtime.RunPodSandboxResponse{PodSandboxId: id}, nil
}

// getNetworkPlugin returns the network plugin to be used by the runtime class
// defaults to the global CNI options in the CRI config
func (c *criService) getNetworkPlugin(runtimeClass string) cni.CNI {
	if c.netPlugin == nil {
		return nil
	}
	i, ok := c.netPlugin[runtimeClass]
	if !ok {
		if i, ok = c.netPlugin[defaultNetworkPlugin]; !ok {
			return nil
		}
	}
	return i
}

// setupPodNetwork setups up the network for a pod
func (c *criService) setupPodNetwork(ctx context.Context, sandbox *sandboxstore.Sandbox) error {
	var (
		id        = sandbox.ID
		config    = sandbox.Config
		path      = sandbox.NetNSPath
		netPlugin = c.getNetworkPlugin(sandbox.RuntimeHandler)
	)
	if netPlugin == nil {
		return errors.New("cni config not initialized")
	}

	opts, err := cniNamespaceOpts(id, config)
	if err != nil {
		return fmt.Errorf("get cni namespace options: %w", err)
	}
	log.G(ctx).WithField("podsandboxid", id).Debugf("begin cni setup")
	result, err := netPlugin.Setup(ctx, id, path, opts...)
	if err != nil {
		return err
	}
	logDebugCNIResult(ctx, id, result)
	// Check if the default interface has IP config
	if configs, ok := result.Interfaces[defaultIfName]; ok && len(configs.IPConfigs) > 0 {
		sandbox.IP, sandbox.AdditionalIPs = selectPodIPs(ctx, configs.IPConfigs, c.config.IPPreference)
		sandbox.CNIResult = result
		return nil
	}
	return fmt.Errorf("failed to find network info for sandbox %q", id)
}

// cniNamespaceOpts get CNI namespace options from sandbox config.
func cniNamespaceOpts(id string, config *runtime.PodSandboxConfig) ([]cni.NamespaceOpts, error) {
	opts := []cni.NamespaceOpts{
		cni.WithLabels(toCNILabels(id, config)),
		cni.WithCapability(annotations.PodAnnotations, config.Annotations),
	}

	portMappings := toCNIPortMappings(config.GetPortMappings())
	if len(portMappings) > 0 {
		opts = append(opts, cni.WithCapabilityPortMap(portMappings))
	}

	// Will return an error if the bandwidth limitation has the wrong unit
	// or an unreasonable value see validateBandwidthIsReasonable()
	bandWidth, err := toCNIBandWidth(config.Annotations)
	if err != nil {
		return nil, err
	}
	if bandWidth != nil {
		opts = append(opts, cni.WithCapabilityBandWidth(*bandWidth))
	}

	dns := toCNIDNS(config.GetDnsConfig())
	if dns != nil {
		opts = append(opts, cni.WithCapabilityDNS(*dns))
	}

	return opts, nil
}

// toCNILabels adds pod metadata into CNI labels.
func toCNILabels(id string, config *runtime.PodSandboxConfig) map[string]string {
	return map[string]string{
		"K8S_POD_NAMESPACE":          config.GetMetadata().GetNamespace(),
		"K8S_POD_NAME":               config.GetMetadata().GetName(),
		"K8S_POD_INFRA_CONTAINER_ID": id,
		"K8S_POD_UID":                config.GetMetadata().GetUid(),
		"IgnoreUnknown":              "1",
	}
}

// toCNIBandWidth converts CRI annotations to CNI bandwidth.
func toCNIBandWidth(annotations map[string]string) (*cni.BandWidth, error) {
	ingress, egress, err := bandwidth.ExtractPodBandwidthResources(annotations)
	if err != nil {
		return nil, fmt.Errorf("reading pod bandwidth annotations: %w", err)
	}

	if ingress == nil && egress == nil {
		return nil, nil
	}

	bandWidth := &cni.BandWidth{}

	if ingress != nil {
		bandWidth.IngressRate = uint64(ingress.Value())
		bandWidth.IngressBurst = math.MaxUint32
	}

	if egress != nil {
		bandWidth.EgressRate = uint64(egress.Value())
		bandWidth.EgressBurst = math.MaxUint32
	}

	return bandWidth, nil
}

// toCNIPortMappings converts CRI port mappings to CNI.
func toCNIPortMappings(criPortMappings []*runtime.PortMapping) []cni.PortMapping {
	var portMappings []cni.PortMapping
	for _, mapping := range criPortMappings {
		if mapping.HostPort <= 0 {
			continue
		}
		portMappings = append(portMappings, cni.PortMapping{
			HostPort:      mapping.HostPort,
			ContainerPort: mapping.ContainerPort,
			Protocol:      strings.ToLower(mapping.Protocol.String()),
			HostIP:        mapping.HostIp,
		})
	}
	return portMappings
}

// toCNIDNS converts CRI DNSConfig to CNI.
func toCNIDNS(dns *runtime.DNSConfig) *cni.DNS {
	if dns == nil {
		return nil
	}
	return &cni.DNS{
		Servers:  dns.GetServers(),
		Searches: dns.GetSearches(),
		Options:  dns.GetOptions(),
	}
}

// selectPodIPs select an ip from the ip list.
func selectPodIPs(ctx context.Context, configs []*cni.IPConfig, preference string) (string, []string) {
	if len(configs) == 1 {
		return ipString(configs[0]), nil
	}
	toStrings := func(ips []*cni.IPConfig) (o []string) {
		for _, i := range ips {
			o = append(o, ipString(i))
		}
		return o
	}
	var extra []string
	switch preference {
	default:
		if preference != "ipv4" && preference != "" {
			log.G(ctx).WithField("ip_pref", preference).Warn("invalid ip_pref, falling back to ipv4")
		}
		for i, ip := range configs {
			if ip.IP.To4() != nil {
				return ipString(ip), append(extra, toStrings(configs[i+1:])...)
			}
			extra = append(extra, ipString(ip))
		}
	case "ipv6":
		for i, ip := range configs {
			if ip.IP.To16() != nil {
				return ipString(ip), append(extra, toStrings(configs[i+1:])...)
			}
			extra = append(extra, ipString(ip))
		}
	case "cni":
		// use func default return
	}

	all := toStrings(configs)
	return all[0], all[1:]
}

func ipString(ip *cni.IPConfig) string {
	return ip.IP.String()
}

// untrustedWorkload returns true if the sandbox contains untrusted workload.
func untrustedWorkload(config *runtime.PodSandboxConfig) bool {
	return config.GetAnnotations()[annotations.UntrustedWorkload] == "true"
}

// hostAccessingSandbox returns true if the sandbox configuration
// requires additional host access for the sandbox.
func hostAccessingSandbox(config *runtime.PodSandboxConfig) bool {
	securityContext := config.GetLinux().GetSecurityContext()

	namespaceOptions := securityContext.GetNamespaceOptions()
	if namespaceOptions.GetNetwork() == runtime.NamespaceMode_NODE ||
		namespaceOptions.GetPid() == runtime.NamespaceMode_NODE ||
		namespaceOptions.GetIpc() == runtime.NamespaceMode_NODE {
		return true
	}

	return false
}

// getSandboxRuntime returns the runtime configuration for sandbox.
// If the sandbox contains untrusted workload, runtime for untrusted workload will be returned,
// or else default runtime will be returned.
func (c *criService) getSandboxRuntime(config *runtime.PodSandboxConfig, runtimeHandler string) (criconfig.Runtime, error) {
	if untrustedWorkload(config) {
		// If the untrusted annotation is provided, runtimeHandler MUST be empty.
		if runtimeHandler != "" && runtimeHandler != criconfig.RuntimeUntrusted {
			return criconfig.Runtime{}, errors.New("untrusted workload with explicit runtime handler is not allowed")
		}

		//  If the untrusted workload is requesting access to the host/node, this request will fail.
		//
		//  Note: If the workload is marked untrusted but requests privileged, this can be granted, as the
		// runtime may support this.  For example, in a virtual-machine isolated runtime, privileged
		// is a supported option, granting the workload to access the entire guest VM instead of host.
		// TODO(windows): Deprecate this so that we don't need to handle it for windows.
		if hostAccessingSandbox(config) {
			return criconfig.Runtime{}, errors.New("untrusted workload with host access is not allowed")
		}

		runtimeHandler = criconfig.RuntimeUntrusted
	}

	if runtimeHandler == "" {
		runtimeHandler = c.config.ContainerdConfig.DefaultRuntimeName
	}

	handler, ok := c.config.ContainerdConfig.Runtimes[runtimeHandler]
	if !ok {
		return criconfig.Runtime{}, fmt.Errorf("no runtime for %q is configured", runtimeHandler)
	}
	return handler, nil
}

// getSandboxController returns the sandbox controller configuration for sandbox.
// If absent in legacy case, it will return the default controller.
func (c *criService) getSandboxController(config *runtime.PodSandboxConfig, runtimeHandler string) (sb.Controller, error) {
	ociRuntime, err := c.getSandboxRuntime(config, runtimeHandler)
	if err != nil {
		return nil, fmt.Errorf("failed to get sandbox runtime: %w", err)
	}
	// Validate mode
	if err = ValidateMode(ociRuntime.SandboxMode); err != nil {
		return nil, err
	}
	// Use sandbox controller to delete sandbox
	controller, exist := c.sandboxControllers[criconfig.SandboxControllerMode(ociRuntime.SandboxMode)]
	if !exist {
		return nil, fmt.Errorf("sandbox controller %s not exist", ociRuntime.SandboxMode)
	}
	return controller, nil
}

func logDebugCNIResult(ctx context.Context, sandboxID string, result *cni.Result) {
	if logrus.GetLevel() < logrus.DebugLevel {
		return
	}
	cniResult, err := json.Marshal(result)
	if err != nil {
		log.G(ctx).WithField("podsandboxid", sandboxID).WithError(err).Errorf("Failed to marshal CNI result: %v", err)
		return
	}
	log.G(ctx).WithField("podsandboxid", sandboxID).Debugf("cni result: %s", string(cniResult))
}