build: basis of build command

Signed-off-by: Tonis Tiigi <tonistiigi@gmail.com>

build/build.go

@@ -0,0 +1,193 @@
+package build
+
+import (
+	"context"
+	"io"
+	"os"
+	"path/filepath"
+	"strconv"
+	"strings"
+
+	"github.com/containerd/console"
+	"github.com/containerd/containerd/platforms"
+	"github.com/moby/buildkit/client"
+	"github.com/moby/buildkit/session"
+	"github.com/moby/buildkit/util/progress/progressui"
+	specs "github.com/opencontainers/image-spec/specs-go/v1"
+	"github.com/pkg/errors"
+	"golang.org/x/sync/errgroup"
+)
+
+type Options struct {
+	Inputs    Inputs
+	Tags      []string
+	Labels    map[string]string
+	BuildArgs map[string]string
+	Pull      bool
+
+	NoCache   bool
+	Target    string
+	Platforms []specs.Platform
+	Exports   []client.ExportEntry
+	Session   []session.Attachable
+
+	// DockerTarget
+}
+
+type Inputs struct {
+	ContextPath    string
+	DockerfilePath string
+	InStream       io.Reader
+}
+
+func Build(ctx context.Context, c *client.Client, opt Options, pw *ProgressWriter) (*client.SolveResponse, error) {
+	so := client.SolveOpt{
+		Frontend:      "dockerfile.v0",
+		FrontendAttrs: map[string]string{},
+	}
+
+	if len(opt.Exports) > 1 {
+		return nil, errors.Errorf("multiple outputs currently unsupported")
+	}
+
+	if len(opt.Tags) > 0 {
+		for i, e := range opt.Exports {
+			switch e.Type {
+			case "image", "oci", "docker":
+				opt.Exports[i].Attrs["name"] = strings.Join(opt.Tags, ",")
+			}
+		}
+	} else {
+		for _, e := range opt.Exports {
+			if e.Type == "image" && e.Attrs["name"] == "" && e.Attrs["push"] != "" {
+				if ok, _ := strconv.ParseBool(e.Attrs["push"]); ok {
+					return nil, errors.Errorf("tag is needed when pushing to registry")
+				}
+			}
+		}
+	}
+	// TODO: handle loading to docker daemon
+
+	so.Exports = opt.Exports
+	so.Session = opt.Session
+
+	if err := LoadInputs(opt.Inputs, &so); err != nil {
+		return nil, err
+	}
+
+	if opt.Pull {
+		so.FrontendAttrs["image-resolve-mode"] = "pull"
+	}
+	if opt.Target != "" {
+		so.FrontendAttrs["target"] = opt.Target
+	}
+	if opt.NoCache {
+		so.FrontendAttrs["no-cache"] = ""
+	}
+	for k, v := range opt.BuildArgs {
+		so.FrontendAttrs["build-arg:"+k] = v
+	}
+	for k, v := range opt.Labels {
+		so.FrontendAttrs["label:"+k] = v
+	}
+
+	if len(opt.Platforms) != 0 {
+		pp := make([]string, len(opt.Platforms))
+		for i, p := range opt.Platforms {
+			pp[i] = platforms.Format(p)
+		}
+		so.FrontendAttrs["platform"] = strings.Join(pp, ",")
+	}
+
+	eg, ctx := errgroup.WithContext(ctx)
+
+	var statusCh chan *client.SolveStatus
+	if pw != nil {
+		statusCh = pw.Status()
+		eg.Go(func() error {
+			<-pw.Done()
+			return pw.Err()
+		})
+	}
+
+	var resp *client.SolveResponse
+	eg.Go(func() error {
+		var err error
+		resp, err = c.Solve(ctx, nil, so, statusCh)
+		if err != nil {
+			return err
+		}
+		return nil
+	})
+
+	if err := eg.Wait(); err != nil {
+		return nil, err
+	}
+
+	return resp, nil
+}
+
+type ProgressWriter struct {
+	status chan *client.SolveStatus
+	done   <-chan struct{}
+	err    error
+}
+
+func (pw *ProgressWriter) Done() <-chan struct{} {
+	return pw.done
+}
+
+func (pw *ProgressWriter) Err() error {
+	return pw.err
+}
+
+func (pw *ProgressWriter) Status() chan *client.SolveStatus {
+	return pw.status
+}
+
+func NewProgressWriter(ctx context.Context, out *os.File, mode string) *ProgressWriter {
+	statusCh := make(chan *client.SolveStatus)
+	doneCh := make(chan struct{})
+
+	pw := &ProgressWriter{
+		status: statusCh,
+		done:   doneCh,
+	}
+
+	go func() {
+		var c console.Console
+		if cons, err := console.ConsoleFromFile(out); err == nil && (mode == "auto" || mode == "tty") {
+			c = cons
+		}
+		// not using shared context to not disrupt display but let is finish reporting errors
+		pw.err = progressui.DisplaySolveStatus(ctx, "", c, out, statusCh)
+		close(doneCh)
+	}()
+	return pw
+}
+
+func LoadInputs(inp Inputs, target *client.SolveOpt) error {
+	if inp.ContextPath == "" {
+		return errors.New("please specify build context (e.g. \".\" for the current directory)")
+	}
+
+	// TODO: handle stdin, symlinks, remote contexts, check files exist
+
+	if inp.DockerfilePath == "" {
+		inp.DockerfilePath = filepath.Join(inp.ContextPath, "Dockerfile")
+	}
+
+	if target.LocalDirs == nil {
+		target.LocalDirs = map[string]string{}
+	}
+
+	target.LocalDirs["context"] = inp.ContextPath
+	target.LocalDirs["dockerfile"] = filepath.Dir(inp.DockerfilePath)
+
+	if target.FrontendAttrs == nil {
+		target.FrontendAttrs = map[string]string{}
+	}
+
+	target.FrontendAttrs["filename"] = filepath.Base(inp.DockerfilePath)
+	return nil
+}