driver kubernetes: allow to work in a Memory mount to speed up things

Signed-off-by: Samuel Archambault <samuel.archambault@getmaintainx.com>

driver/kubernetes/factory.go

@@ -286,6 +286,10 @@ func (f *factory) processDriverOpts(deploymentName string, namespace string, cfg
 			if v != "" {
 				deploymentOpt.Qemu.Image = v
 			}
+		case "buildkit-root-volume-memory":
+			if v != "" {
+				deploymentOpt.BuildKitRootVolumeMemory = v
+			}
 		case "default-load":
 			defaultLoad, err = strconv.ParseBool(v)
 			if err != nil {

driver/kubernetes/manifest/manifest.go

@@ -32,6 +32,7 @@ type DeploymentOpt struct {
 	// files mounted at /etc/buildkitd
 	ConfigFiles map[string][]byte
 
+	BuildKitRootVolumeMemory string
 	Rootless                 bool
 	NodeSelector             map[string]string
 	CustomAnnotations        map[string]string
@@ -50,6 +51,8 @@ const (
 	containerName      = "buildkitd"
 	AnnotationPlatform = "buildx.docker.com/platform"
 	LabelApp           = "app"
+	rootVolumeName     = "buildkit-memory"
+	rootVolumePath     = "/var/lib/buildkit"
 )
 
 type ErrReservedAnnotationPlatform struct{}
@@ -247,6 +250,26 @@ func NewDeployment(opt *DeploymentOpt) (d *appsv1.Deployment, c []*corev1.Config
 		d.Spec.Template.Spec.Containers[0].Resources.Limits[corev1.ResourceEphemeralStorage] = limEphemeralStorage
 	}
 
+	if opt.BuildKitRootVolumeMemory != "" {
+		buildKitRootVolumeMemory, err := resource.ParseQuantity(opt.BuildKitRootVolumeMemory)
+		if err != nil {
+			return nil, nil, err
+		}
+		d.Spec.Template.Spec.Volumes = append(d.Spec.Template.Spec.Volumes, corev1.Volume{
+			Name: rootVolumeName,
+			VolumeSource: corev1.VolumeSource{
+				EmptyDir: &corev1.EmptyDirVolumeSource{
+					Medium:    "Memory",
+					SizeLimit: &buildKitRootVolumeMemory,
+				},
+			},
+		})
+		d.Spec.Template.Spec.Containers[0].VolumeMounts = append(d.Spec.Template.Spec.Containers[0].VolumeMounts, corev1.VolumeMount{
+			Name:      rootVolumeName,
+			MountPath: rootVolumePath,
+		})
+	}
+
 	return
 }