communicate with plugin using json events

Signed-off-by: Nicolas De Loof <nicolas.deloof@gmail.com>

pkg/compose/convergence.go

@@ -111,7 +111,7 @@ func (c *convergence) apply(ctx context.Context, project *types.Project, options
 
 func (c *convergence) ensureService(ctx context.Context, project *types.Project, service types.ServiceConfig, recreate string, inherit bool, timeout *time.Duration) error { //nolint:gocyclo
 	if service.External != nil {
-		return c.service.runPlugin(ctx, project, service, "create")
+		return c.service.runPlugin(ctx, project, service, "up")
 	}
 	expected, err := getScale(service)
 	if err != nil {

pkg/compose/down.go

@@ -83,8 +83,11 @@ func (s *composeService) down(ctx context.Context, projectName string, options a
 	}
 
 	err = InReverseDependencyOrder(ctx, project, func(c context.Context, service string) error {
-		serviceContainers := containers.filter(isService(service))
 		serv := project.Services[service]
+		if serv.External != nil {
+			return s.runPlugin(ctx, project, serv, "down")
+		}
+		serviceContainers := containers.filter(isService(service))
 		err := s.removeContainers(ctx, serviceContainers, &serv, options.Timeout, options.Volumes)
 		return err
 	}, WithRootNodesAndDown(options.Services))

pkg/compose/plugins.go

@@ -17,10 +17,10 @@
 package compose
 
 import (
-	"bufio"
 	"context"
-	"errors"
+	"encoding/json"
 	"fmt"
+	"io"
 	"os"
 	"os/exec"
 	"strings"
@@ -28,27 +28,43 @@ import (
 	"github.com/compose-spec/compose-go/v2/types"
 	"github.com/docker/cli/cli-plugins/manager"
 	"github.com/docker/cli/cli-plugins/socket"
+	"github.com/docker/compose/v2/pkg/progress"
+	"github.com/docker/docker/errdefs"
+	"github.com/pkg/errors"
 	"github.com/spf13/cobra"
 	"go.opentelemetry.io/otel"
 	"go.opentelemetry.io/otel/propagation"
 	"golang.org/x/sync/errgroup"
 )
 
+type JsonMessage struct {
+	Type    string `json:"type"`
+	Message string `json:"message"`
+}
+
+const (
+	ErrorType  = "error"
+	InfoType   = "info"
+	SetEnvType = "setenv"
+)
+
 func (s *composeService) runPlugin(ctx context.Context, project *types.Project, service types.ServiceConfig, command string) error {
 	x := *service.External
-	if x.Type != "model" {
-		return fmt.Errorf("unsupported external service type %s", x.Type)
-	}
+
+	// Only support Docker CLI plugins for first iteration. Could support any binary from PATH
 	plugin, err := manager.GetPlugin(x.Type, s.dockerCli, &cobra.Command{})
 	if err != nil {
+		if errdefs.IsNotFound(err) {
+			return fmt.Errorf("unsupported external service type %s", x.Type)
+		}
 		return err
 	}
 
-	model, ok := x.Options["model"]
-	if !ok {
-		return errors.New("model option is required")
+	args := []string{"compose", "--project-name", project.Name, command}
+	for k, v := range x.Options {
+		args = append(args, fmt.Sprintf("--%s=%s", k, v))
 	}
-	args := []string{"pull", model}
+
 	cmd := exec.CommandContext(ctx, plugin.Path, args...)
 	// Remove DOCKER_CLI_PLUGIN... variable so plugin can detect it run standalone
 	cmd.Env = filter(os.Environ(), manager.ReexecEnvvar)
@@ -68,13 +84,11 @@ func (s *composeService) runPlugin(ctx context.Context, project *types.Project,
 	otel.GetTextMapPropagator().Inject(ctx, &carrier)
 	cmd.Env = append(cmd.Env, types.Mapping(carrier).Values()...)
 
-	var variables []string
 	eg := errgroup.Group{}
-	out, err := cmd.StdoutPipe()
+	stdout, err := cmd.StdoutPipe()
 	if err != nil {
 		return err
 	}
-	cmd.Stderr = os.Stderr
 
 	err = cmd.Start()
 	if err != nil {
@@ -82,24 +96,52 @@ func (s *composeService) runPlugin(ctx context.Context, project *types.Project,
 	}
 	eg.Go(cmd.Wait)
 
-	scanner := bufio.NewScanner(out)
-	scanner.Split(bufio.ScanLines)
-	for scanner.Scan() {
-		line := scanner.Text()
-		variables = append(variables, line)
+	decoder := json.NewDecoder(stdout)
+	defer stdout.Close()
+
+	variables := types.Mapping{}
+
+	pw := progress.ContextWriter(ctx)
+	pw.Event(progress.CreatingEvent(service.Name))
+	for {
+		var msg JsonMessage
+		err = decoder.Decode(&msg)
+		if err == io.EOF {
+			break
+		}
+		if err != nil {
+			return err
+		}
+		switch msg.Type {
+		case ErrorType:
+			pw.Event(progress.ErrorMessageEvent(service.Name, "error"))
+			return errors.New(msg.Message)
+		case InfoType:
+			pw.Event(progress.ErrorMessageEvent(service.Name, msg.Message))
+		case SetEnvType:
+			key, val, found := strings.Cut(msg.Message, "=")
+			if !found {
+				return fmt.Errorf("invalid response from plugin: %s", msg.Message)
+			}
+			variables[key] = val
+		default:
+			return fmt.Errorf("invalid response from plugin: %s", msg.Type)
+		}
 	}
 
 	err = eg.Wait()
 	if err != nil {
-		return err
+		pw.Event(progress.ErrorMessageEvent(service.Name, err.Error()))
+		return errors.Wrapf(err, "failed to create external service")
 	}
+	pw.Event(progress.CreatedEvent(service.Name))
 
-	variable := fmt.Sprintf("%s_URL", strings.ToUpper(service.Name))
-	// FIXME can we obtain this URL from Docker Destktop API ?
-	url := "http://host.docker.internal:12434/engines/llama.cpp/v1/"
+	prefix := strings.ToUpper(service.Name) + "_"
 	for name, s := range project.Services {
 		if _, ok := s.DependsOn[service.Name]; ok {
-			s.Environment[variable] = &url
+			for key, val := range variables {
+				s.Environment[prefix+key] = &val
+			}
 			project.Services[name] = s
 		}
 	}