process.go

// +build !windows

/*
   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 proc

import (
	"context"
	"io"
	"sync"
	"time"

	"github.com/containerd/console"
	"github.com/pkg/errors"
)

// RuncRoot is the path to the root runc state directory
const RuncRoot = "/run/containerd/runc"

// Stdio of a process
type Stdio struct {
	Stdin    string
	Stdout   string
	Stderr   string
	Terminal bool
}

// IsNull returns true if the stdio is not defined
func (s Stdio) IsNull() bool {
	return s.Stdin == "" && s.Stdout == "" && s.Stderr == ""
}

// Process on a linux system
type Process interface {
	State
	// ID returns the id for the process
	ID() string
	// Pid returns the pid for the process
	Pid() int
	// ExitStatus returns the exit status
	ExitStatus() int
	// ExitedAt is the time the process exited
	ExitedAt() time.Time
	// Stdin returns the process STDIN
	Stdin() io.Closer
	// Stdio returns io information for the container
	Stdio() Stdio
	// Status returns the process status
	Status(context.Context) (string, error)
	// Wait blocks until the process has exited
	Wait()
}

// State of a process
type State interface {
	// Resize resizes the process console
	Resize(ws console.WinSize) error
	// Start execution of the process
	Start(context.Context) error
	// Delete deletes the process and its resourcess
	Delete(context.Context) error
	// Kill kills the process
	Kill(context.Context, uint32, bool) error
	// SetExited sets the exit status for the process
	SetExited(status int)
}

func stateName(v interface{}) string {
	switch v.(type) {
	case *runningState, *execRunningState:
		return "running"
	case *createdState, *execCreatedState, *createdCheckpointState:
		return "created"
	case *pausedState:
		return "paused"
	case *deletedState:
		return "deleted"
	case *stoppedState:
		return "stopped"
	}
	panic(errors.Errorf("invalid state %v", v))
}

// Platform handles platform-specific behavior that may differs across
// platform implementations
type Platform interface {
	CopyConsole(ctx context.Context, console console.Console, stdin, stdout, stderr string,
		wg, cwg *sync.WaitGroup) (console.Console, error)
	ShutdownConsole(ctx context.Context, console console.Console) error
	Close() error
}