dotcloud/docker

package build // import "github.com/docker/docker/api/server/backend/build"

import (
    "context"
    "fmt"
    "strconv"

    "github.com/distribution/reference"
    "github.com/docker/docker/api/types"
    "github.com/docker/docker/api/types/backend"
    "github.com/docker/docker/api/types/events"
    "github.com/docker/docker/builder"
    buildkit "github.com/docker/docker/builder/builder-next"
    daemonevents "github.com/docker/docker/daemon/events"
    "github.com/docker/docker/image"
    "github.com/docker/docker/pkg/stringid"
    "github.com/pkg/errors"
    "google.golang.org/grpc"
)

// ImageComponent provides an interface for working with images
type ImageComponent interface {
    SquashImage(from string, to string) (string, error)
    TagImage(context.Context, image.ID, reference.Named) error
}

// Builder defines interface for running a build
type Builder interface {
    Build(context.Context, backend.BuildConfig) (*builder.Result, error)
}

// Backend provides build functionality to the API router
type Backend struct {
    builder        Builder
    imageComponent ImageComponent
    buildkit       *buildkit.Builder
    eventsService  *daemonevents.Events
}

// NewBackend creates a new build backend from components
func NewBackend(components ImageComponent, builder Builder, buildkit *buildkit.Builder, es *daemonevents.Events) (*Backend, error) {
    return &Backend{imageComponent: components, builder: builder, buildkit: buildkit, eventsService: es}, nil
}

// RegisterGRPC registers buildkit controller to the grpc server.
func (b *Backend) RegisterGRPC(s *grpc.Server) {
    if b.buildkit != nil {
        b.buildkit.RegisterGRPC(s)
    }
}

// Build builds an image from a Source
func (b *Backend) Build(ctx context.Context, config backend.BuildConfig) (string, error) {
    options := config.Options
    useBuildKit := options.Version == types.BuilderBuildKit

    tags, err := sanitizeRepoAndTags(options.Tags)
    if err != nil {
        return "", err
    }

    var build *builder.Result
    if useBuildKit {
        build, err = b.buildkit.Build(ctx, config)
        if err != nil {
            return "", err
        }
    } else {
        build, err = b.builder.Build(ctx, config)
        if err != nil {
            return "", err
        }
    }

    if build == nil {
        return "", nil
    }

    imageID := build.ImageID
    if options.Squash {
        if imageID, err = squashBuild(build, b.imageComponent); err != nil {
            return "", err
        }
        if config.ProgressWriter.AuxFormatter != nil {
            if err = config.ProgressWriter.AuxFormatter.Emit("moby.image.id", types.BuildResult{ID: imageID}); err != nil {
                return "", err
            }
        }
    }

    if imageID != "" && !useBuildKit {
        stdout := config.ProgressWriter.StdoutFormatter
        _, _ = fmt.Fprintf(stdout, "Successfully built %s\n", stringid.TruncateID(imageID))
        err = tagImages(ctx, b.imageComponent, config.ProgressWriter.StdoutFormatter, image.ID(imageID), tags)
    }
    return imageID, err
}

// PruneCache removes all cached build sources
func (b *Backend) PruneCache(ctx context.Context, opts types.BuildCachePruneOptions) (*types.BuildCachePruneReport, error) {
    buildCacheSize, cacheIDs, err := b.buildkit.Prune(ctx, opts)
    if err != nil {
        return nil, errors.Wrap(err, "failed to prune build cache")
    }
    b.eventsService.Log(events.ActionPrune, events.BuilderEventType, events.Actor{
        Attributes: map[string]string{
            "reclaimed": strconv.FormatInt(buildCacheSize, 10),
        },
    })
    return &types.BuildCachePruneReport{SpaceReclaimed: uint64(buildCacheSize), CachesDeleted: cacheIDs}, nil
}

// Cancel cancels the build by ID
func (b *Backend) Cancel(ctx context.Context, id string) error {
    return b.buildkit.Cancel(ctx, id)
}

func squashBuild(build *builder.Result, imageComponent ImageComponent) (string, error) {
    var fromID string
    if build.FromImage != nil {
        fromID = build.FromImage.ImageID()
    }
    imageID, err := imageComponent.SquashImage(build.ImageID, fromID)
    if err != nil {
        return "", errors.Wrap(err, "error squashing image")
    }
    return imageID, nil
}