containerd/linux/runtime.go

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// +build linux
package linux
import (
"bytes"
"fmt"
"io"
"io/ioutil"
"os"
"path/filepath"
"time"
"github.com/containerd/containerd"
"github.com/containerd/containerd/api/services/shim"
"github.com/containerd/containerd/api/types/container"
"github.com/containerd/containerd/api/types/mount"
"github.com/containerd/containerd/log"
"github.com/containerd/containerd/plugin"
"golang.org/x/net/context"
)
const (
runtimeName = "linux"
configFilename = "config.json"
defaultRuntime = "runc"
)
func init() {
plugin.Register(runtimeName, &plugin.Registration{
Type: plugin.RuntimePlugin,
Init: New,
Config: &Config{},
})
}
type Config struct {
// Runtime is a path or name of an OCI runtime used by the shim
Runtime string `toml:"runtime"`
// NoShim calls runc directly from within the pkg
NoShim bool `toml:"no_shim"`
}
func New(ic *plugin.InitContext) (interface{}, error) {
path := filepath.Join(ic.State, runtimeName)
if err := os.MkdirAll(path, 0700); err != nil {
return nil, err
}
cfg := ic.Config.(*Config)
if cfg.Runtime == "" {
cfg.Runtime = defaultRuntime
}
c, cancel := context.WithCancel(ic.Context)
return &Runtime{
root: path,
remote: !cfg.NoShim,
runtime: cfg.Runtime,
events: make(chan *containerd.Event, 2048),
eventsContext: c,
eventsCancel: cancel,
monitor: ic.Monitor,
}, nil
}
type Runtime struct {
root string
runtime string
remote bool
events chan *containerd.Event
eventsContext context.Context
eventsCancel func()
monitor plugin.ContainerMonitor
}
func (r *Runtime) Create(ctx context.Context, id string, opts containerd.CreateOpts) (containerd.Container, error) {
path, err := r.newBundle(id, opts.Spec)
if err != nil {
return nil, err
}
s, err := newShim(path, r.remote)
if err != nil {
os.RemoveAll(path)
return nil, err
}
if err := r.handleEvents(s); err != nil {
os.RemoveAll(path)
return nil, err
}
sopts := &shim.CreateRequest{
ID: id,
Bundle: path,
Runtime: r.runtime,
Stdin: opts.IO.Stdin,
Stdout: opts.IO.Stdout,
Stderr: opts.IO.Stderr,
Terminal: opts.IO.Terminal,
}
for _, m := range opts.Rootfs {
sopts.Rootfs = append(sopts.Rootfs, &mount.Mount{
Type: m.Type,
Source: m.Source,
Options: m.Options,
})
}
if _, err := s.Create(ctx, sopts); err != nil {
os.RemoveAll(path)
return nil, err
}
c := &Container{
id: id,
shim: s,
}
// after the container is create add it to the monitor
if err := r.monitor.Monitor(c); err != nil {
return nil, err
}
return c, nil
}
func (r *Runtime) Delete(ctx context.Context, c containerd.Container) (uint32, error) {
lc, ok := c.(*Container)
if !ok {
return 0, fmt.Errorf("container cannot be cast as *linux.Container")
}
// remove the container from the monitor
if err := r.monitor.Stop(lc); err != nil {
// TODO: log error here
return 0, err
}
rsp, err := lc.shim.Delete(ctx, &shim.DeleteRequest{})
if err != nil {
return 0, err
}
lc.shim.Exit(ctx, &shim.ExitRequest{})
return rsp.ExitStatus, r.deleteBundle(lc.id)
}
func (r *Runtime) Containers() ([]containerd.Container, error) {
dir, err := ioutil.ReadDir(r.root)
if err != nil {
return nil, err
}
var o []containerd.Container
for _, fi := range dir {
if !fi.IsDir() {
continue
}
c, err := r.loadContainer(filepath.Join(r.root, fi.Name()))
if err != nil {
return nil, err
}
o = append(o, c)
}
return o, nil
}
func (r *Runtime) Events(ctx context.Context) <-chan *containerd.Event {
return r.events
}
func (r *Runtime) handleEvents(s shim.ShimClient) error {
events, err := s.Events(r.eventsContext, &shim.EventsRequest{})
if err != nil {
return err
}
go r.forward(events)
return nil
}
func (r *Runtime) forward(events shim.Shim_EventsClient) {
for {
e, err := events.Recv()
if err != nil {
log.G(r.eventsContext).WithError(err).Error("get event from shim")
return
}
var et containerd.EventType
switch e.Type {
case container.Event_CREATE:
et = containerd.CreateEvent
case container.Event_EXEC_ADDED:
et = containerd.ExecAddEvent
case container.Event_EXIT:
et = containerd.ExitEvent
case container.Event_OOM:
et = containerd.OOMEvent
case container.Event_START:
et = containerd.StartEvent
}
r.events <- &containerd.Event{
Timestamp: time.Now(),
Runtime: runtimeName,
Type: et,
Pid: e.Pid,
ID: e.ID,
ExitStatus: e.ExitStatus,
}
}
}
func (r *Runtime) newBundle(id string, spec []byte) (string, error) {
path := filepath.Join(r.root, id)
if err := os.Mkdir(path, 0700); err != nil {
return "", err
}
if err := os.Mkdir(filepath.Join(path, "rootfs"), 0700); err != nil {
return "", err
}
f, err := os.Create(filepath.Join(path, configFilename))
if err != nil {
return "", err
}
defer f.Close()
_, err = io.Copy(f, bytes.NewReader(spec))
return path, err
}
func (r *Runtime) deleteBundle(id string) error {
return os.RemoveAll(filepath.Join(r.root, id))
}
func (r *Runtime) loadContainer(path string) (*Container, error) {
id := filepath.Base(path)
s, err := loadShim(path, r.remote)
if err != nil {
return nil, err
}
return &Container{
id: id,
shim: s,
}, nil
}