Option to mount HostPath in each Kaniko Pod to be used as cache volume

examples/annotated-skaffold.yaml

@@ -140,6 +140,8 @@ build:
   #     localDir: {}
   #   cache:
   #     repo: gcr.io/my-project/skaffold/cache
+  #     hostPath: host path used as base image cache to mount in each kaniko container.
+  #               If set, must exist on each node and prepopulated with kaniko-warmer
   #   flags:
   #     - --aditional-flag
   #   pullSecret: /a/secret/path/serviceaccount.json

pkg/skaffold/build/build.go

@@ -31,7 +31,7 @@ type Artifact struct {
 }
 
 // Builder is an interface to the Build API of Skaffold.
-// It must build and make the resulting image accesible to the cluster.
+// It must build and make the resulting image accessible to the cluster.
 // This could include pushing to a authorized repository or loading the nodes with the image.
 // If artifacts is supplied, the builder should only rebuild those artifacts.
 type Builder interface {

pkg/skaffold/build/kaniko/run.go

@@ -22,6 +22,7 @@ import (
 	"io"
 
 	"github.com/GoogleContainerTools/skaffold/pkg/skaffold/build/kaniko/sources"
+	"github.com/GoogleContainerTools/skaffold/pkg/skaffold/constants"
 	"github.com/GoogleContainerTools/skaffold/pkg/skaffold/docker"
 	"github.com/GoogleContainerTools/skaffold/pkg/skaffold/kubernetes"
 	"github.com/GoogleContainerTools/skaffold/pkg/skaffold/schema/latest"
@@ -62,6 +63,9 @@ func (b *Builder) run(ctx context.Context, out io.Writer, artifact *latest.Artif
 		if b.Cache.Repo != "" {
 			args = append(args, fmt.Sprintf("--cache-repo=%s", b.Cache.Repo))
 		}
+		if b.Cache.HostPath != "" {
+			args = append(args, fmt.Sprintf("--cache-dir=%s", constants.DefaultKanikoDockerConfigPath))
+		}
 	}
 
 	podSpec := s.Pod(args)

pkg/skaffold/build/kaniko/sources/sources.go

@@ -86,6 +86,25 @@ func podTemplate(cfg *latest.KanikoBuild, args []string) *v1.Pod {
 		},
 	}
 
+	if cfg.Cache.HostPath != "" {
+		volumeMount := v1.VolumeMount{
+			Name:      constants.DefaultKanikoCacheDirName,
+			MountPath: constants.DefaultKanikoCacheDirMountPath,
+		}
+
+		pod.Spec.Containers[0].VolumeMounts = append(pod.Spec.Containers[0].VolumeMounts, volumeMount)
+
+		volume := v1.Volume{
+			Name: constants.DefaultKanikoCacheDirName,
+			VolumeSource: v1.VolumeSource{
+				HostPath: &v1.HostPathVolumeSource{
+					Path: cfg.Cache.HostPath,
+				},
+			},
+		}
+		pod.Spec.Volumes = append(pod.Spec.Volumes, volume)
+	}
+
 	if cfg.DockerConfig == nil {
 		return pod
 	}

pkg/skaffold/constants/constants.go

@@ -51,6 +51,8 @@ const (
 	DefaultKanikoContainerName          = "kaniko"
 	DefaultKanikoEmptyDirName           = "kaniko-emptydir"
 	DefaultKanikoEmptyDirMountPath      = "/kaniko/buildcontext"
+	DefaultKanikoCacheDirName           = "kaniko-cache"
+	DefaultKanikoCacheDirMountPath      = "/cache"
 	DefaultKanikoDockerConfigSecretName = "docker-cfg"
 	DefaultKanikoDockerConfigPath       = "/kaniko/.docker"
 

pkg/skaffold/schema/latest/config.go

@@ -228,6 +228,9 @@ type KanikoCache struct {
 	// Repo is a remote repository to store cached layers. If none is specified, one will be
 	// inferred from the image name. See [Kaniko Caching](https://github.com/GoogleContainerTools/kaniko#caching).
 	Repo string `yaml:"repo,omitempty"`
+
+	// HostPath specifies a path on the host that is mounted to each pod as read only cache volume containing base images.
+	HostPath string `yaml:"hostPath,omitempty"`
 }
 
 // KanikoBuild (beta) describes how to do an on-cluster build using