Simplify image config build

This requires callers to pass in a default image config instead of
expecting the function to resolve a config from an image ref.
This makes things a bit easier to integrate with and not making
assumptions that the base config is going to come from an image ref.

In the future I plan to make the default base config to by built-in
rather than always pulling from an image ref.
This will save a round trip with the registry and makes ure we aren't
relying on an image in the registry that we wouldn't otherwise need to.

Signed-off-by: Brian Goff <cpuguy83@gmail.com>

frontend/azlinux/handle_container.go

@@ -53,30 +53,9 @@ func handleContainer(w worker) gwclient.BuildFunc {
  return nil, nil, err
  }
 
- var img *dalec.DockerImageSpec
- if base := frontend.GetBaseOutputImage(spec, targetKey, ""); base != "" {
- _, _, dt, err := client.ResolveImageConfig(ctx, base, sourceresolver.Opt{})
- if err != nil {
- return nil, nil, errors.Wrap(err, "error resolving base image config")
- }
- var cfg dalec.DockerImageSpec
- if err := json.Unmarshal(dt, &cfg); err != nil {
- return nil, nil, errors.Wrap(err, "error unmarshalling base image config")
- }
- img = &cfg
- } else {
- img, err = w.DefaultImageConfig(ctx, client)
- if err != nil {
- return nil, nil, errors.Wrap(err, "could not get default image config")
- }
- }
-
- // TODO: DNM: This is not merging the image config from the spec.
- specImg := frontend.MergeSpecImage(spec, targetKey)
-
- err = dalec.MergeImageConfig(&img.Config, specImg)
+ img, err := resolveBaseConfig(ctx, client, platform, spec, targetKey)
  if err != nil {
- return nil, nil, err
+ return nil, nil, errors.Wrap(err, "could not resolve base image config")
  }
 
  ref, err := res.SingleRef()
@@ -147,7 +126,7 @@ func specToContainerLLB(w worker, client gwclient.Client, spec *dalec.Spec, targ
  builderImg := w.Base(client, opts...)
 
  rootfs := llb.Scratch()
- if ref := frontend.GetBaseOutputImage(spec, target, ""); ref != "" {
+ if ref := dalec.GetBaseOutputImage(spec, target); ref != "" {
  rootfs = llb.Image(ref, llb.WithMetaResolver(sOpt.Resolver), dalec.WithConstraints(opts...))
  }
 
@@ -213,3 +192,25 @@ type runOptionFunc func(*llb.ExecInfo)
 func (f runOptionFunc) SetRunOption(ei *llb.ExecInfo) {
  f(ei)
 }
+
+func resolveBaseConfig(ctx context.Context, resolver llb.ImageMetaResolver, platform *ocispecs.Platform, spec *dalec.Spec, targetKey string) (*dalec.DockerImageSpec, error) {
+ baseRef := dalec.GetBaseOutputImage(spec, targetKey)
+ if baseRef == "" {
+ baseRef = mariner2DistrolessRef
+ }
+
+ _, _, dt, err := resolver.ResolveImageConfig(ctx, baseRef, sourceresolver.Opt{Platform: platform})
+ if err != nil {
+ return nil, errors.Wrap(err, "error resolving base image config")
+ }
+
+ var img dalec.DockerImageSpec
+ if err := json.Unmarshal(dt, &img); err != nil {
+ return nil, errors.Wrap(err, "error unmarshalling base image config")
+ }
+
+ if err := dalec.BuildImageConfig(spec, targetKey, &img); err != nil {
+ return nil, err
+ }
+ return &img, nil
+}

frontend/azlinux/handle_depsonly.go

@@ -2,16 +2,13 @@ package azlinux
 
 import (
  "context"
- "encoding/json"
  "strings"
 
  "github.com/Azure/dalec"
  "github.com/Azure/dalec/frontend"
  "github.com/moby/buildkit/client/llb"
- "github.com/moby/buildkit/client/llb/sourceresolver"
  gwclient "github.com/moby/buildkit/frontend/gateway/client"
  ocispecs "github.com/opencontainers/image-spec/specs-go/v1"
- "github.com/pkg/errors"
 )
 
 func handleDepsOnly(w worker) gwclient.BuildFunc {
@@ -51,22 +48,9 @@ func handleDepsOnly(w worker) gwclient.BuildFunc {
  return nil, nil, err
  }
 
- var img *dalec.DockerImageSpec
- if base := frontend.GetBaseOutputImage(spec, targetKey, ""); base != "" {
- _, _, dt, err := client.ResolveImageConfig(ctx, base, sourceresolver.Opt{})
- if err != nil {
- return nil, nil, errors.Wrap(err, "error resolving base image config")
- }
- var cfg dalec.DockerImageSpec
- if err := json.Unmarshal(dt, &cfg); err != nil {
- return nil, nil, errors.Wrap(err, "error unmarshalling base image config")
- }
- img = &cfg
- } else {
- img, err = w.DefaultImageConfig(ctx, client)
- if err != nil {
- return nil, nil, errors.Wrap(err, "could not get default image config")
- }
+ img, err := resolveBaseConfig(ctx, client, platform, spec, targetKey)
+ if err != nil {
+ return nil, nil, err
  }
 
  ref, err := res.SingleRef()

frontend/windows/handle_container.go

@@ -2,15 +2,18 @@ package windows
 
 import (
  "context"
+ "encoding/json"
  "fmt"
  "runtime"
 
  "github.com/Azure/dalec"
  "github.com/Azure/dalec/frontend"
  "github.com/moby/buildkit/client/llb"
+ "github.com/moby/buildkit/client/llb/sourceresolver"
  "github.com/moby/buildkit/frontend/dockerui"
  gwclient "github.com/moby/buildkit/frontend/gateway/client"
  ocispecs "github.com/opencontainers/image-spec/specs-go/v1"
+ "github.com/pkg/errors"
 )
 
 const (
@@ -73,16 +76,29 @@ func handleContainer(ctx context.Context, client gwclient.Client) (*gwclient.Res
  return nil, nil, err
  }
 
- base := frontend.GetBaseOutputImage(spec, targetKey, defaultBaseImage)
+ imgRef := dalec.GetBaseOutputImage(spec, targetKey)
+ if imgRef == "" {
+ imgRef = defaultBaseImage
+ }
 
- img, err := frontend.BuildImageConfig(ctx, client, spec, targetKey, base, frontend.WithPlatform(targetPlatform))
+ _, _, dt, err := client.ResolveImageConfig(ctx, imgRef, sourceresolver.Opt{
+ Platform: &targetPlatform,
+ })
  if err != nil {
- return nil, nil, err
+ return nil, nil, errors.Wrap(err, "could not resolve base image config")
  }
 
- ref, err := res.SingleRef()
+ var img dalec.DockerImageSpec
+ if err := json.Unmarshal(dt, &img); err != nil {
+ return nil, nil, errors.Wrap(err, "error unmarshalling base image config")
+ }
+
+ if err := dalec.BuildImageConfig(spec, targetKey, &img); err != nil {
+ return nil, nil, errors.Wrap(err, "error creating image config")
+ }
 
- return ref, img, err
+ ref, err := res.SingleRef()
+ return ref, &img, err
  })
 }
 

imgconfig.go

@@ -0,0 +1,61 @@
+package dalec
+
+func BuildImageConfig(spec *Spec, targetKey string, img *DockerImageSpec) error {
+ cfg := img.Config
+ if err := MergeImageConfig(&cfg, MergeSpecImage(spec, targetKey)); err != nil {
+ return err
+ }
+
+ img.Config = cfg
+ return nil
+}
+
+func GetBaseOutputImage(spec *Spec, target string) string {
+ i := spec.Targets[target].Image
+ if i == nil || i.Base == "" {
+ return ""
+ }
+ return i.Base
+}
+
+func MergeSpecImage(spec *Spec, targetKey string) *ImageConfig {
+ var cfg ImageConfig
+
+ if spec.Image != nil {
+ cfg = *spec.Image
+ }
+
+ if i := spec.Targets[targetKey].Image; i != nil {
+ if i.Entrypoint != "" {
+ cfg.Entrypoint = i.Entrypoint
+ }
+
+ if i.Cmd != "" {
+ cfg.Cmd = i.Cmd
+ }
+
+ cfg.Env = append(cfg.Env, i.Env...)
+
+ for k, v := range i.Volumes {
+ cfg.Volumes[k] = v
+ }
+
+ for k, v := range i.Labels {
+ cfg.Labels[k] = v
+ }
+
+ if i.WorkingDir != "" {
+ cfg.WorkingDir = i.WorkingDir
+ }
+
+ if i.StopSignal != "" {
+ cfg.StopSignal = i.StopSignal
+ }
+
+ if i.Base != "" {
+ cfg.Base = i.Base
+ }
+ }
+
+ return &cfg
+}