moby/container/exec.go
Cory Snider 4bafaa00aa Refactor libcontainerd to minimize c8d RPCs
The containerd client is very chatty at the best of times. Because the
libcontained API is stateless and references containers and processes by
string ID for every method call, the implementation is essentially
forced to use the containerd client in a way which amplifies the number
of redundant RPCs invoked to perform any operation. The libcontainerd
remote implementation has to reload the containerd container, task
and/or process metadata for nearly every operation. This in turn
amplifies the number of context switches between dockerd and containerd
to perform any container operation or handle a containerd event,
increasing the load on the system which could otherwise be allocated to
workloads.

Overhaul the libcontainerd interface to reduce the impedance mismatch
with the containerd client so that the containerd client can be used
more efficiently. Split the API out into container, task and process
interfaces which the consumer is expected to retain so that
libcontainerd can retain state---especially the analogous containerd
client objects---without having to manage any state-store inside the
libcontainerd client.

Signed-off-by: Cory Snider <csnider@mirantis.com>
2022-08-24 14:59:08 -04:00

131 lines
3.1 KiB
Go

package container // import "github.com/docker/docker/container"
import (
"runtime"
"sync"
"github.com/containerd/containerd/cio"
"github.com/docker/docker/container/stream"
"github.com/docker/docker/libcontainerd/types"
"github.com/docker/docker/pkg/stringid"
"github.com/sirupsen/logrus"
)
// ExecConfig holds the configurations for execs. The Daemon keeps
// track of both running and finished execs so that they can be
// examined both during and after completion.
type ExecConfig struct {
sync.Mutex
Started chan struct{}
StreamConfig *stream.Config
ID string
Running bool
ExitCode *int
OpenStdin bool
OpenStderr bool
OpenStdout bool
CanRemove bool
Container *Container
DetachKeys []byte
Entrypoint string
Args []string
Tty bool
Privileged bool
User string
WorkingDir string
Env []string
Process types.Process
ConsoleSize *[2]uint
}
// NewExecConfig initializes the a new exec configuration
func NewExecConfig(c *Container) *ExecConfig {
return &ExecConfig{
ID: stringid.GenerateRandomID(),
Container: c,
StreamConfig: stream.NewConfig(),
Started: make(chan struct{}),
}
}
// InitializeStdio is called by libcontainerd to connect the stdio.
func (c *ExecConfig) InitializeStdio(iop *cio.DirectIO) (cio.IO, error) {
c.StreamConfig.CopyToPipe(iop)
if c.StreamConfig.Stdin() == nil && !c.Tty && runtime.GOOS == "windows" {
if iop.Stdin != nil {
if err := iop.Stdin.Close(); err != nil {
logrus.Errorf("error closing exec stdin: %+v", err)
}
}
}
return &rio{IO: iop, sc: c.StreamConfig}, nil
}
// CloseStreams closes the stdio streams for the exec
func (c *ExecConfig) CloseStreams() error {
return c.StreamConfig.CloseStreams()
}
// SetExitCode sets the exec config's exit code
func (c *ExecConfig) SetExitCode(code int) {
c.ExitCode = &code
}
// ExecStore keeps track of the exec configurations.
type ExecStore struct {
byID map[string]*ExecConfig
mu sync.RWMutex
}
// NewExecStore initializes a new exec store.
func NewExecStore() *ExecStore {
return &ExecStore{
byID: make(map[string]*ExecConfig),
}
}
// Commands returns the exec configurations in the store.
func (e *ExecStore) Commands() map[string]*ExecConfig {
e.mu.RLock()
byID := make(map[string]*ExecConfig, len(e.byID))
for id, config := range e.byID {
byID[id] = config
}
e.mu.RUnlock()
return byID
}
// Add adds a new exec configuration to the store.
func (e *ExecStore) Add(id string, Config *ExecConfig) {
e.mu.Lock()
e.byID[id] = Config
e.mu.Unlock()
}
// Get returns an exec configuration by its id.
func (e *ExecStore) Get(id string) *ExecConfig {
e.mu.RLock()
res := e.byID[id]
e.mu.RUnlock()
return res
}
// Delete removes an exec configuration from the store.
func (e *ExecStore) Delete(id string) {
e.mu.Lock()
delete(e.byID, id)
e.mu.Unlock()
}
// List returns the list of exec ids in the store.
func (e *ExecStore) List() []string {
var IDs []string
e.mu.RLock()
for id := range e.byID {
IDs = append(IDs, id)
}
e.mu.RUnlock()
return IDs
}