containerd/linux/task.go
Stephen J Day 539742881d
api/services: define the container metadata service
Working from feedback on the existing implementation, we have now
introduced a central metadata object to represent the lifecycle and pin
the resources required to implement what people today know as
containers. This includes the runtime specification and the root
filesystem snapshots. We also allow arbitrary labeling of the container.
Such provisions will bring the containerd definition of container closer
to what is expected by users.

The objects that encompass today's ContainerService, centered around the
runtime, will be known as tasks. These tasks take on the existing
lifecycle behavior of containerd's containers, which means that they are
deleted when they exit. Largely, there are no other changes except for
naming.

The `Container` object will operate purely as a metadata object. No
runtime state will be held on `Container`. It only informs the execution
service on what is required for creating tasks and the resources in use
by that container. The resources referenced by that container will be
deleted when the container is deleted, if not in use. In this sense,
users can create, list, label and delete containers in a similar way as
they do with docker today, without the complexity of runtime locks that
plagues current implementations.

Signed-off-by: Stephen J Day <stephen.day@docker.com>
2017-05-22 23:27:53 -07:00

188 lines
3.9 KiB
Go

// +build linux
package linux
import (
"context"
"github.com/containerd/containerd/api/services/shim"
"github.com/containerd/containerd/api/types/task"
"github.com/containerd/containerd/plugin"
protobuf "github.com/gogo/protobuf/types"
specs "github.com/opencontainers/runtime-spec/specs-go"
)
type State struct {
pid uint32
status plugin.Status
}
func (s State) Pid() uint32 {
return s.pid
}
func (s State) Status() plugin.Status {
return s.status
}
type Task struct {
containerID string
spec []byte
shim shim.ShimClient
}
func newTask(id string, spec []byte, shim shim.ShimClient) *Task {
return &Task{
containerID: id,
shim: shim,
spec: spec,
}
}
func (c *Task) Info() plugin.TaskInfo {
return plugin.TaskInfo{
ContainerID: c.containerID,
Runtime: runtimeName,
Spec: c.spec,
}
}
func (c *Task) Start(ctx context.Context) error {
_, err := c.shim.Start(ctx, &shim.StartRequest{})
return err
}
func (c *Task) State(ctx context.Context) (plugin.State, error) {
response, err := c.shim.State(ctx, &shim.StateRequest{})
if err != nil {
return nil, err
}
var status plugin.Status
switch response.Status {
case task.StatusCreated:
status = plugin.CreatedStatus
case task.StatusRunning:
status = plugin.RunningStatus
case task.StatusStopped:
status = plugin.StoppedStatus
case task.StatusPaused:
status = plugin.PausedStatus
// TODO: containerd.DeletedStatus
}
return &State{
pid: response.Pid,
status: status,
}, nil
}
func (c *Task) Pause(ctx context.Context) error {
_, err := c.shim.Pause(ctx, &shim.PauseRequest{})
return err
}
func (c *Task) Resume(ctx context.Context) error {
_, err := c.shim.Resume(ctx, &shim.ResumeRequest{})
return err
}
func (c *Task) Kill(ctx context.Context, signal uint32, pid uint32, all bool) error {
_, err := c.shim.Kill(ctx, &shim.KillRequest{
Signal: signal,
Pid: pid,
All: all,
})
return err
}
func (c *Task) Exec(ctx context.Context, opts plugin.ExecOpts) (plugin.Process, error) {
request := &shim.ExecRequest{
Stdin: opts.IO.Stdin,
Stdout: opts.IO.Stdout,
Stderr: opts.IO.Stderr,
Terminal: opts.IO.Terminal,
Spec: &protobuf.Any{
TypeUrl: specs.Version,
Value: opts.Spec,
},
}
resp, err := c.shim.Exec(ctx, request)
if err != nil {
return nil, err
}
return &Process{
pid: int(resp.Pid),
c: c,
}, nil
}
func (c *Task) Processes(ctx context.Context) ([]uint32, error) {
resp, err := c.shim.Processes(ctx, &shim.ProcessesRequest{
ID: c.containerID,
})
if err != nil {
return nil, err
}
pids := make([]uint32, 0, len(resp.Processes))
for _, ps := range resp.Processes {
pids = append(pids, ps.Pid)
}
return pids, nil
}
func (c *Task) Pty(ctx context.Context, pid uint32, size plugin.ConsoleSize) error {
_, err := c.shim.Pty(ctx, &shim.PtyRequest{
Pid: pid,
Width: size.Width,
Height: size.Height,
})
return err
}
func (c *Task) CloseStdin(ctx context.Context, pid uint32) error {
_, err := c.shim.CloseStdin(ctx, &shim.CloseStdinRequest{
Pid: pid,
})
return err
}
func (c *Task) Checkpoint(ctx context.Context, opts plugin.CheckpointOpts) error {
_, err := c.shim.Checkpoint(ctx, &shim.CheckpointRequest{
Exit: opts.Exit,
AllowTcp: opts.AllowTCP,
AllowUnixSockets: opts.AllowUnixSockets,
AllowTerminal: opts.AllowTerminal,
FileLocks: opts.FileLocks,
EmptyNamespaces: opts.EmptyNamespaces,
Image: opts.Path,
})
return err
}
type Process struct {
pid int
c *Task
}
func (p *Process) Kill(ctx context.Context, signal uint32, _ bool) error {
_, err := p.c.shim.Kill(ctx, &shim.KillRequest{
Signal: signal,
Pid: uint32(p.pid),
})
return err
}
func (p *Process) State(ctx context.Context) (plugin.State, error) {
// use the container status for the status of the process
state, err := p.c.State(ctx)
if err != nil {
return nil, err
}
state.(*State).pid = uint32(p.pid)
return state, nil
}