fix: s2i build as-dockerfile mode

s2i/builder.go

@@ -1,14 +1,22 @@
 package s2i
 
 import (
+	"archive/tar"
 	"context"
+	"encoding/json"
 	"errors"
 	"fmt"
+	"io"
+	"io/fs"
 	"net/url"
 	"os"
+	"path/filepath"
 
+	"github.com/docker/docker/api/types"
 	dockerClient "github.com/docker/docker/client"
-
+	"github.com/google/go-containerregistry/pkg/name"
+	v1 "github.com/google/go-containerregistry/pkg/v1"
+	"github.com/google/go-containerregistry/pkg/v1/remote"
 	"github.com/openshift/source-to-image/pkg/api"
 	"github.com/openshift/source-to-image/pkg/api/validation"
 	"github.com/openshift/source-to-image/pkg/build"
@@ -17,7 +25,7 @@ import (
 	"github.com/openshift/source-to-image/pkg/scm/git"
 
 	fn "knative.dev/kn-plugin-func"
-	docker "knative.dev/kn-plugin-func/docker"
+	"knative.dev/kn-plugin-func/docker"
 )
 
 var (
@@ -36,10 +44,17 @@ var DefaultBuilderImages = map[string]string{
 	"quarkus":    "registry.access.redhat.com/ubi8/openjdk-17",
 }
 
+// DockerClient is subset of dockerClient.CommonAPIClient required by this package
+type DockerClient interface {
+	ImageBuild(ctx context.Context, context io.Reader, options types.ImageBuildOptions) (types.ImageBuildResponse, error)
+	ImageInspectWithRaw(ctx context.Context, image string) (types.ImageInspect, []byte, error)
+}
+
 // Builder of Functions using the s2i subsystem.
 type Builder struct {
 	verbose bool
 	impl    build.Builder // S2I builder implementation (aka "Strategy")
+	cli     DockerClient
 }
 
 type Option func(*Builder)
@@ -60,6 +75,12 @@ func WithImpl(s build.Builder) Option {
 	}
 }
 
+func WithDockerClient(cli DockerClient) Option {
+	return func(b *Builder) {
+		b.cli = cli
+	}
+}
+
 // NewBuilder creates a new instance of a Builder with static defaults.
 func NewBuilder(options ...Option) *Builder {
 	b := &Builder{}
@@ -70,6 +91,8 @@ func NewBuilder(options ...Option) *Builder {
 }
 
 func (b *Builder) Build(ctx context.Context, f fn.Function) (err error) {
+	// TODO this function currently doesn't support private s2i builder images since credentials are not set
+
 	// Builder image from the Function  if defined, default otherwise.
 	builderImage, err := builderImage(f)
 	if err != nil {
@@ -87,6 +110,27 @@ func (b *Builder) Build(ctx context.Context, f fn.Function) (err error) {
 	cfg.RuntimeImagePullPolicy = api.DefaultRuntimeImagePullPolicy
 	cfg.DockerConfig = s2idocker.GetDefaultDockerConfig()
 
+	tmp, err := os.MkdirTemp("", "s2i-build")
+	if err != nil {
+		return fmt.Errorf("cannot create temporary dir for s2i build: %w", err)
+	}
+	defer os.RemoveAll(tmp)
+
+	cfg.AsDockerfile = filepath.Join(tmp, "Dockerfile")
+
+	if b.cli == nil {
+		b.cli, _, err = docker.NewClient(dockerClient.DefaultDockerHost)
+		if err != nil {
+			return fmt.Errorf("cannot create docker client: %w", err)
+		}
+	}
+
+	scriptURL, err := s2iScriptURL(ctx, b.cli, cfg.BuilderImage)
+	if err != nil {
+		return fmt.Errorf("cannot get s2i script url: %w", err)
+	}
+	cfg.ScriptsURL = scriptURL
+
 	// Excludes
 	// Do not include .git, .env, .func or any language-specific cache directories
 	// (node_modules, etc) in the tar file sent to the builder, as this both
@@ -115,20 +159,9 @@ func (b *Builder) Build(ctx context.Context, f fn.Function) (err error) {
 
 	// Create the S2I builder instance if not overridden
 	if b.impl == nil {
-		var client dockerClient.CommonAPIClient
-		client, _, err = docker.NewClient(dockerClient.DefaultDockerHost)
-		if err != nil {
-			return
-		}
-		defer client.Close()
-
-		if isPodman(ctx, client) {
-			client = podmanDockerClient{client}
-		}
-
-		b.impl, _, err = strategies.Strategy(client, cfg, build.Overrides{})
+		b.impl, _, err = strategies.Strategy(nil, cfg, build.Overrides{})
 		if err != nil {
-			return
+			return fmt.Errorf("cannot create s2i builder: %w", err)
 		}
 	}
 
@@ -143,7 +176,150 @@ func (b *Builder) Build(ctx context.Context, f fn.Function) (err error) {
 			fmt.Println(message)
 		}
 	}
-	return
+
+	pr, pw := io.Pipe()
+
+	go func() {
+		tw := tar.NewWriter(pw)
+		err := filepath.Walk(tmp, func(path string, fi fs.FileInfo, err error) error {
+			if err != nil {
+				return err
+			}
+
+			p, err := filepath.Rel(tmp, path)
+			if err != nil {
+				return fmt.Errorf("cannot get relative path: %w", err)
+			}
+
+			hdr, err := tar.FileInfoHeader(fi, p)
+			if err != nil {
+				return fmt.Errorf("cannot create tar header: %w", err)
+			}
+			hdr.Name = p
+
+			err = tw.WriteHeader(hdr)
+			if err != nil {
+				return fmt.Errorf("cannot write header to thar stream: %w", err)
+			}
+			if fi.Mode().IsRegular() {
+				var r io.ReadCloser
+				r, err = os.Open(path)
+				if err != nil {
+					return fmt.Errorf("cannot open source file: %w", err)
+				}
+				_, err = io.Copy(tw, r)
+				if err != nil {
+					return fmt.Errorf("cannot copy file to tar stream :%w", err)
+				}
+			}
+
+			return nil
+		})
+		_ = tw.Close()
+		_ = pw.CloseWithError(err)
+	}()
+
+	opts := types.ImageBuildOptions{
+		Tags: []string{f.Image},
+	}
+
+	resp, err := b.cli.ImageBuild(ctx, pr, opts)
+	if err != nil {
+		return fmt.Errorf("cannot build the app image: %w", err)
+	}
+	defer resp.Body.Close()
+
+	var out io.Writer = io.Discard
+	if b.verbose {
+		out = os.Stderr
+	}
+
+	errMsg, err := parseBuildResponse(resp.Body, out)
+	if err != nil {
+		return fmt.Errorf("cannot parse response body: %w", err)
+	}
+	if errMsg != "" {
+		return fmt.Errorf("cannot build the app: %s", errMsg)
+	}
+
+	return nil
+}
+
+func parseBuildResponse(r io.Reader, w io.Writer) (errorMessage string, err error) {
+	obj := struct {
+		ErrorDetail struct {
+			Message string `json:"message"`
+		} `json:"errorDetail"`
+		Stream string `json:"stream"`
+	}{}
+	d := json.NewDecoder(r)
+	for {
+		err = d.Decode(&obj)
+		if err != nil {
+			if errors.Is(err, io.EOF) {
+				break
+			}
+			return "", err
+		}
+		if obj.ErrorDetail.Message != "" {
+			errorMessage = obj.ErrorDetail.Message
+			return errorMessage, nil
+		}
+		if obj.Stream != "" {
+			_, err = w.Write([]byte(obj.Stream))
+			if err != nil {
+				return "", err
+			}
+		}
+	}
+	return "", nil
+}
+
+func s2iScriptURL(ctx context.Context, cli DockerClient, image string) (string, error) {
+	img, _, err := cli.ImageInspectWithRaw(ctx, image)
+	if err != nil {
+		if dockerClient.IsErrNotFound(err) { // image is not in the daemon, get info directly from registry
+			var (
+				ref name.Reference
+				img v1.Image
+				cfg *v1.ConfigFile
+			)
+
+			ref, err = name.ParseReference(image)
+			if err != nil {
+				return "", fmt.Errorf("cannot parse image name: %w", err)
+			}
+			img, err = remote.Image(ref)
+			if err != nil {
+				return "", fmt.Errorf("cannot get image from registry: %w", err)
+			}
+			cfg, err = img.ConfigFile()
+			if err != nil {
+				return "", fmt.Errorf("cannot get config for image: %w", err)
+			}
+
+			if cfg.Config.Labels != nil {
+				if u, ok := cfg.Config.Labels["io.openshift.s2i.scripts-url"]; ok {
+					return u, nil
+				}
+			}
+		}
+		return "", err
+	}
+
+	if img.Config != nil && img.Config.Labels != nil {
+		if u, ok := img.Config.Labels["io.openshift.s2i.scripts-url"]; ok {
+			return u, nil
+		}
+	}
+
+	if img.ContainerConfig != nil && img.ContainerConfig.Labels != nil {
+		if u, ok := img.ContainerConfig.Labels["io.openshift.s2i.scripts-url"]; ok {
+			return u, nil
+		}
+	}
+
+	return "", nil
 }
 
 // builderImage for Function