fix: ctx should cancel image pull on run

This patch fixes the context cancellation
behaviour for the `runContainer` function,
specifically the `createContainer` function
introduced in this commit 991b1303da.

It delays stripping the `cancel` from the context
passed into the `runContainer` function so that
the `createContainer` function can be cancelled
gracefully by a SIGTERM/SIGINT.

This is especially true when the requested image
does not exist and `docker run` needs to `pull`
the image before creating the container.

Although this patch does gracefully cancel
the `runContainer` function it does not address
the root cause. Some functions in the call path
are not context aware, such as `pullImage`.

Future work would still be necessary to ensure
a consistent behaviour in the CLI.

Signed-off-by: Alano Terblanche <18033717+Benehiko@users.noreply.github.com>
This commit is contained in:
Alano Terblanche 2024-11-22 14:13:40 +01:00
parent 682cf57d73
commit 30a73ff19c
No known key found for this signature in database
GPG Key ID: 0E8FACD1BA98DE27
4 changed files with 93 additions and 9 deletions

View File

@ -25,7 +25,7 @@ type fakeClient struct {
platform *specs.Platform,
containerName string) (container.CreateResponse, error)
containerStartFunc func(containerID string, options container.StartOptions) error
imageCreateFunc func(parentReference string, options image.CreateOptions) (io.ReadCloser, error)
imageCreateFunc func(ctx context.Context, parentReference string, options image.CreateOptions) (io.ReadCloser, error)
infoFunc func() (system.Info, error)
containerStatPathFunc func(containerID, path string) (container.PathStat, error)
containerCopyFromFunc func(containerID, srcPath string) (io.ReadCloser, container.PathStat, error)
@ -100,9 +100,9 @@ func (f *fakeClient) ContainerRemove(ctx context.Context, containerID string, op
return nil
}
func (f *fakeClient) ImageCreate(_ context.Context, parentReference string, options image.CreateOptions) (io.ReadCloser, error) {
func (f *fakeClient) ImageCreate(ctx context.Context, parentReference string, options image.CreateOptions) (io.ReadCloser, error) {
if f.imageCreateFunc != nil {
return f.imageCreateFunc(parentReference, options)
return f.imageCreateFunc(ctx, parentReference, options)
}
return nil, nil
}

View File

@ -132,7 +132,7 @@ func TestCreateContainerImagePullPolicy(t *testing.T) {
return container.CreateResponse{ID: containerID}, nil
}
},
imageCreateFunc: func(parentReference string, options image.CreateOptions) (io.ReadCloser, error) {
imageCreateFunc: func(ctx context.Context, parentReference string, options image.CreateOptions) (io.ReadCloser, error) {
defer func() { pullCounter++ }()
return io.NopCloser(strings.NewReader("")), nil
},

View File

@ -118,8 +118,6 @@ func runRun(ctx context.Context, dockerCli command.Cli, flags *pflag.FlagSet, ro
//nolint:gocyclo
func runContainer(ctx context.Context, dockerCli command.Cli, runOpts *runOptions, copts *containerOptions, containerCfg *containerConfig) error {
ctx = context.WithoutCancel(ctx)
config := containerCfg.Config
stdout, stderr := dockerCli.Out(), dockerCli.Err()
apiClient := dockerCli.Client()
@ -141,9 +139,6 @@ func runContainer(ctx context.Context, dockerCli command.Cli, runOpts *runOption
config.StdinOnce = false
}
ctx, cancelFun := context.WithCancel(ctx)
defer cancelFun()
containerID, err := createContainer(ctx, dockerCli, containerCfg, &runOpts.createOptions)
if err != nil {
return toStatusError(err)
@ -159,6 +154,9 @@ func runContainer(ctx context.Context, dockerCli command.Cli, runOpts *runOption
defer signal.StopCatch(sigc)
}
ctx, cancelFun := context.WithCancel(context.WithoutCancel(ctx))
defer cancelFun()
var (
waitDisplayID chan struct{}
errCh chan error

View File

@ -2,7 +2,9 @@ package container
import (
"context"
"encoding/json"
"errors"
"fmt"
"io"
"net"
"syscall"
@ -16,7 +18,9 @@ import (
"github.com/docker/cli/internal/test/notary"
"github.com/docker/docker/api/types"
"github.com/docker/docker/api/types/container"
"github.com/docker/docker/api/types/image"
"github.com/docker/docker/api/types/network"
"github.com/docker/docker/pkg/jsonmessage"
specs "github.com/opencontainers/image-spec/specs-go/v1"
"github.com/spf13/pflag"
"gotest.tools/v3/assert"
@ -217,6 +221,88 @@ func TestRunAttachTermination(t *testing.T) {
}
}
func TestRunPullTermination(t *testing.T) {
ctx, cancel := context.WithCancel(context.Background())
t.Cleanup(cancel)
attachCh := make(chan struct{})
fakeCLI := test.NewFakeCli(&fakeClient{
createContainerFunc: func(config *container.Config, hostConfig *container.HostConfig, networkingConfig *network.NetworkingConfig,
platform *specs.Platform, containerName string,
) (container.CreateResponse, error) {
select {
case <-ctx.Done():
return container.CreateResponse{}, ctx.Err()
default:
}
return container.CreateResponse{}, fakeNotFound{}
},
containerAttachFunc: func(ctx context.Context, containerID string, options container.AttachOptions) (types.HijackedResponse, error) {
return types.HijackedResponse{}, errors.New("shouldn't try to attach to a container")
},
imageCreateFunc: func(ctx context.Context, parentReference string, options image.CreateOptions) (io.ReadCloser, error) {
server, client := net.Pipe()
t.Cleanup(func() {
_ = server.Close()
})
go func() {
enc := json.NewEncoder(server)
for i := 0; i < 100; i++ {
select {
case <-ctx.Done():
assert.NilError(t, server.Close(), "failed to close imageCreateFunc server")
return
default:
}
assert.NilError(t, enc.Encode(jsonmessage.JSONMessage{
Status: "Downloading",
ID: fmt.Sprintf("id-%d", i),
TimeNano: time.Now().UnixNano(),
Time: time.Now().Unix(),
Progress: &jsonmessage.JSONProgress{
Current: int64(i),
Total: 100,
Start: 0,
},
}))
time.Sleep(100 * time.Millisecond)
}
}()
attachCh <- struct{}{}
return client, nil
},
Version: "1.30",
})
cmd := NewRunCommand(fakeCLI)
cmd.SetOut(io.Discard)
cmd.SetErr(io.Discard)
cmd.SetArgs([]string{"foobar:latest"})
cmdErrC := make(chan error, 1)
go func() {
cmdErrC <- cmd.ExecuteContext(ctx)
}()
select {
case <-time.After(5 * time.Second):
t.Fatal("imageCreateFunc was not called before the timeout")
case <-attachCh:
}
cancel()
select {
case cmdErr := <-cmdErrC:
assert.Equal(t, cmdErr, cli.StatusError{
StatusCode: 125,
Status: "docker: context canceled\n\nRun 'docker run --help' for more information",
})
case <-time.After(10 * time.Second):
t.Fatal("cmd did not return before the timeout")
}
}
func TestRunCommandWithContentTrustErrors(t *testing.T) {
testCases := []struct {
name string