solver: merge local and remote images into single list

This also allows us to specify that local images should be generated
with exactly the same specification as remote images, but with the
pkg:oci scheme instead of pkg:docker.

Signed-off-by: Justin Chadwell <[email protected]>

Author: jedevc

solver/llbsolver/provenance/capture.go

@@ -16,6 +16,7 @@ type ImageSource struct {
 	Ref      string
 	Platform *ocispecs.Platform
 	Digest   digest.Digest
+	Local    bool
 }
 
 type GitSource struct {
@@ -43,11 +44,10 @@ type SSH struct {
 }
 
 type Sources struct {
-	Images      []ImageSource
-	LocalImages []ImageSource
-	Git         []GitSource
-	HTTP        []HTTPSource
-	Local       []LocalSource
+	Images []ImageSource
+	Git    []GitSource
+	HTTP   []HTTPSource
+	Local  []LocalSource
 }
 
 type Capture struct {
@@ -67,9 +67,6 @@ func (c *Capture) Merge(c2 *Capture) error {
 	for _, i := range c2.Sources.Images {
 		c.AddImage(i)
 	}
-	for _, i := range c2.Sources.LocalImages {
-		c.AddLocalImage(i)
-	}
 	for _, l := range c2.Sources.Local {
 		c.AddLocal(l)
 	}
@@ -98,9 +95,6 @@ func (c *Capture) Sort() {
 	sort.Slice(c.Sources.Images, func(i, j int) bool {
 		return c.Sources.Images[i].Ref < c.Sources.Images[j].Ref
 	})
-	sort.Slice(c.Sources.LocalImages, func(i, j int) bool {
-		return c.Sources.LocalImages[i].Ref < c.Sources.LocalImages[j].Ref
-	})
 	sort.Slice(c.Sources.Local, func(i, j int) bool {
 		return c.Sources.Local[i].Name < c.Sources.Local[j].Name
 	})
@@ -151,7 +145,7 @@ func (c *Capture) OptimizeImageSources() error {
 
 func (c *Capture) AddImage(i ImageSource) {
 	for _, v := range c.Sources.Images {
-		if v.Ref == i.Ref {
+		if v.Ref == i.Ref && v.Local == i.Local {
 			if v.Platform == i.Platform {
 				return
 			}
@@ -165,22 +159,6 @@ func (c *Capture) AddImage(i ImageSource) {
 	c.Sources.Images = append(c.Sources.Images, i)
 }
 
-func (c *Capture) AddLocalImage(i ImageSource) {
-	for _, v := range c.Sources.LocalImages {
-		if v.Ref == i.Ref {
-			if v.Platform == i.Platform {
-				return
-			}
-			if v.Platform != nil && i.Platform != nil {
-				if v.Platform.Architecture == i.Platform.Architecture && v.Platform.OS == i.Platform.OS && v.Platform.Variant == i.Platform.Variant {
-					return
-				}
-			}
-		}
-	}
-	c.Sources.LocalImages = append(c.Sources.LocalImages, i)
-}
-
 func (c *Capture) AddLocal(l LocalSource) {
 	for _, v := range c.Sources.Local {
 		if v.Name == l.Name {

solver/llbsolver/provenance/predicate.go

@@ -56,11 +56,17 @@ type BuildKitMetadata struct {
 }
 
 func slsaMaterials(srcs Sources) ([]slsa.ProvenanceMaterial, error) {
-	count := len(srcs.Images) + len(srcs.Git) + len(srcs.HTTP) + len(srcs.LocalImages)
+	count := len(srcs.Images) + len(srcs.Git) + len(srcs.HTTP)
 	out := make([]slsa.ProvenanceMaterial, 0, count)
 
 	for _, s := range srcs.Images {
-		uri, err := purl.RefToPURL(packageurl.TypeDocker, s.Ref, s.Platform)
+		var uri string
+		var err error
+		if s.Local {
+			uri, err = purl.RefToPURL(packageurl.TypeOCI, s.Ref, s.Platform)
+		} else {
+			uri, err = purl.RefToPURL(packageurl.TypeDocker, s.Ref, s.Platform)
+		}
 		if err != nil {
 			return nil, err
 		}
@@ -93,26 +99,6 @@ func slsaMaterials(srcs Sources) ([]slsa.ProvenanceMaterial, error) {
 		})
 	}
 
-	for _, s := range srcs.LocalImages {
-		q := []packageurl.Qualifier{}
-		if s.Platform != nil {
-			q = append(q, packageurl.Qualifier{
-				Key:   "platform",
-				Value: platforms.Format(*s.Platform),
-			})
-		}
-		packageurl.NewPackageURL(packageurl.TypeOCI, "", s.Ref, "", q, "")
-
-		material := slsa.ProvenanceMaterial{
-			URI: s.Ref,
-		}
-		if s.Digest != "" {
-			material.Digest = slsa.DigestSet{
-				s.Digest.Algorithm().String(): s.Digest.Hex(),
-			}
-		}
-		out = append(out, material)
-	}
 	return out, nil
 }