new driver: kubernetes

Tested with `kind` and GKE.

Note: "nodes" shown in `docker buildx ls` are unrelated to Kubernetes "nodes".
Probably buildx should come up with an alternative term.

Usage:

  $ kind create cluster
  $ export KUBECONFIG="$(kind get kubeconfig-path --name="kind")"

  $ docker buildx create --driver kubernetes --driver-opt replicas=3 --use
  $ docker buildx build -t foo --load .

`--load` loads the image into the local Docker.

Driver opts:

  - `image=IMAGE` - Sets the container image to be used for running buildkit.
  - `namespace=NS` - Sets the Kubernetes namespace. Defaults to the current namespace.
  - `replicas=N` - Sets the number of `Pod` replicas. Defaults to 1.
  - `rootless=(true|false)` - Run the container as a non-root user without `securityContext.privileged`. Defaults to false.
  - `loadbalance=(sticky|random)` - Load-balancing strategy. If set to "sticky", the pod is chosen using the hash of the context path. Defaults to "sticky"

Signed-off-by: Akihiro Suda <akihiro.suda.cz@hco.ntt.co.jp>

vendor/k8s.io/api/core/v1/annotation_key_constants.go

@@ -0,0 +1,81 @@
+/*
+Copyright 2017 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+// This file should be consistent with pkg/api/annotation_key_constants.go.
+
+package v1
+
+const (
+	// ImagePolicyFailedOpenKey is added to pods created by failing open when the image policy
+	// webhook backend fails.
+	ImagePolicyFailedOpenKey string = "alpha.image-policy.k8s.io/failed-open"
+
+	// PodPresetOptOutAnnotationKey represents the annotation key for a pod to exempt itself from pod preset manipulation
+	PodPresetOptOutAnnotationKey string = "podpreset.admission.kubernetes.io/exclude"
+
+	// MirrorAnnotationKey represents the annotation key set by kubelets when creating mirror pods
+	MirrorPodAnnotationKey string = "kubernetes.io/config.mirror"
+
+	// TolerationsAnnotationKey represents the key of tolerations data (json serialized)
+	// in the Annotations of a Pod.
+	TolerationsAnnotationKey string = "scheduler.alpha.kubernetes.io/tolerations"
+
+	// TaintsAnnotationKey represents the key of taints data (json serialized)
+	// in the Annotations of a Node.
+	TaintsAnnotationKey string = "scheduler.alpha.kubernetes.io/taints"
+
+	// SeccompPodAnnotationKey represents the key of a seccomp profile applied
+	// to all containers of a pod.
+	SeccompPodAnnotationKey string = "seccomp.security.alpha.kubernetes.io/pod"
+
+	// SeccompContainerAnnotationKeyPrefix represents the key of a seccomp profile applied
+	// to one container of a pod.
+	SeccompContainerAnnotationKeyPrefix string = "container.seccomp.security.alpha.kubernetes.io/"
+
+	// SeccompProfileRuntimeDefault represents the default seccomp profile used by container runtime.
+	SeccompProfileRuntimeDefault string = "runtime/default"
+
+	// DeprecatedSeccompProfileDockerDefault represents the default seccomp profile used by docker.
+	// This is now deprecated and should be replaced by SeccompProfileRuntimeDefault.
+	DeprecatedSeccompProfileDockerDefault string = "docker/default"
+
+	// PreferAvoidPodsAnnotationKey represents the key of preferAvoidPods data (json serialized)
+	// in the Annotations of a Node.
+	PreferAvoidPodsAnnotationKey string = "scheduler.alpha.kubernetes.io/preferAvoidPods"
+
+	// ObjectTTLAnnotations represents a suggestion for kubelet for how long it can cache
+	// an object (e.g. secret, config map) before fetching it again from apiserver.
+	// This annotation can be attached to node.
+	ObjectTTLAnnotationKey string = "node.alpha.kubernetes.io/ttl"
+
+	// annotation key prefix used to identify non-convertible json paths.
+	NonConvertibleAnnotationPrefix = "non-convertible.kubernetes.io"
+
+	kubectlPrefix = "kubectl.kubernetes.io/"
+
+	// LastAppliedConfigAnnotation is the annotation used to store the previous
+	// configuration of a resource for use in a three way diff by UpdateApplyAnnotation.
+	LastAppliedConfigAnnotation = kubectlPrefix + "last-applied-configuration"
+
+	// AnnotationLoadBalancerSourceRangesKey is the key of the annotation on a service to set allowed ingress ranges on their LoadBalancers
+	//
+	// It should be a comma-separated list of CIDRs, e.g. `0.0.0.0/0` to
+	// allow full access (the default) or `18.0.0.0/8,56.0.0.0/8` to allow
+	// access only from the CIDRs currently allocated to MIT & the USPS.
+	//
+	// Not all cloud providers support this annotation, though AWS & GCE do.
+	AnnotationLoadBalancerSourceRangesKey = "service.beta.kubernetes.io/load-balancer-source-ranges"
+)

vendor/k8s.io/api/core/v1/doc.go

@@ -0,0 +1,21 @@
+/*
+Copyright 2015 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+// +k8s:openapi-gen=true
+// +k8s:deepcopy-gen=package
+
+// Package v1 is the v1 version of the core API.
+package v1 // import "k8s.io/api/core/v1"

vendor/k8s.io/api/core/v1/objectreference.go

@@ -0,0 +1,33 @@
+/*
+Copyright 2017 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package v1
+
+import (
+	"k8s.io/apimachinery/pkg/runtime/schema"
+)
+
+// IsAnAPIObject allows clients to preemptively get a reference to an API object and pass it to places that
+// intend only to get a reference to that object. This simplifies the event recording interface.
+func (obj *ObjectReference) SetGroupVersionKind(gvk schema.GroupVersionKind) {
+	obj.APIVersion, obj.Kind = gvk.ToAPIVersionAndKind()
+}
+
+func (obj *ObjectReference) GroupVersionKind() schema.GroupVersionKind {
+	return schema.FromAPIVersionAndKind(obj.APIVersion, obj.Kind)
+}
+
+func (obj *ObjectReference) GetObjectKind() schema.ObjectKind { return obj }

vendor/k8s.io/api/core/v1/register.go

@@ -0,0 +1,99 @@
+/*
+Copyright 2015 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package v1
+
+import (
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/runtime"
+	"k8s.io/apimachinery/pkg/runtime/schema"
+)
+
+// GroupName is the group name use in this package
+const GroupName = ""
+
+// SchemeGroupVersion is group version used to register these objects
+var SchemeGroupVersion = schema.GroupVersion{Group: GroupName, Version: "v1"}
+
+// Resource takes an unqualified resource and returns a Group qualified GroupResource
+func Resource(resource string) schema.GroupResource {
+	return SchemeGroupVersion.WithResource(resource).GroupResource()
+}
+
+var (
+	// We only register manually written functions here. The registration of the
+	// generated functions takes place in the generated files. The separation
+	// makes the code compile even when the generated files are missing.
+	SchemeBuilder = runtime.NewSchemeBuilder(addKnownTypes)
+	AddToScheme   = SchemeBuilder.AddToScheme
+)
+
+// Adds the list of known types to the given scheme.
+func addKnownTypes(scheme *runtime.Scheme) error {
+	scheme.AddKnownTypes(SchemeGroupVersion,
+		&Pod{},
+		&PodList{},
+		&PodStatusResult{},
+		&PodTemplate{},
+		&PodTemplateList{},
+		&ReplicationController{},
+		&ReplicationControllerList{},
+		&Service{},
+		&ServiceProxyOptions{},
+		&ServiceList{},
+		&Endpoints{},
+		&EndpointsList{},
+		&Node{},
+		&NodeList{},
+		&NodeProxyOptions{},
+		&Binding{},
+		&Event{},
+		&EventList{},
+		&List{},
+		&LimitRange{},
+		&LimitRangeList{},
+		&ResourceQuota{},
+		&ResourceQuotaList{},
+		&Namespace{},
+		&NamespaceList{},
+		&Secret{},
+		&SecretList{},
+		&ServiceAccount{},
+		&ServiceAccountList{},
+		&PersistentVolume{},
+		&PersistentVolumeList{},
+		&PersistentVolumeClaim{},
+		&PersistentVolumeClaimList{},
+		&PodAttachOptions{},
+		&PodLogOptions{},
+		&PodExecOptions{},
+		&PodPortForwardOptions{},
+		&PodProxyOptions{},
+		&ComponentStatus{},
+		&ComponentStatusList{},
+		&SerializedReference{},
+		&RangeAllocation{},
+		&ConfigMap{},
+		&ConfigMapList{},
+	)
+
+	// Add common types
+	scheme.AddKnownTypes(SchemeGroupVersion, &metav1.Status{})
+
+	// Add the watch version that applies
+	metav1.AddToGroupVersion(scheme, SchemeGroupVersion)
+	return nil
+}

vendor/k8s.io/api/core/v1/resource.go

@@ -0,0 +1,56 @@
+/*
+Copyright 2017 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package v1
+
+import (
+	"k8s.io/apimachinery/pkg/api/resource"
+)
+
+// Returns string version of ResourceName.
+func (self ResourceName) String() string {
+	return string(self)
+}
+
+// Returns the CPU limit if specified.
+func (self *ResourceList) Cpu() *resource.Quantity {
+	if val, ok := (*self)[ResourceCPU]; ok {
+		return &val
+	}
+	return &resource.Quantity{Format: resource.DecimalSI}
+}
+
+// Returns the Memory limit if specified.
+func (self *ResourceList) Memory() *resource.Quantity {
+	if val, ok := (*self)[ResourceMemory]; ok {
+		return &val
+	}
+	return &resource.Quantity{Format: resource.BinarySI}
+}
+
+func (self *ResourceList) Pods() *resource.Quantity {
+	if val, ok := (*self)[ResourcePods]; ok {
+		return &val
+	}
+	return &resource.Quantity{}
+}
+
+func (self *ResourceList) StorageEphemeral() *resource.Quantity {
+	if val, ok := (*self)[ResourceEphemeralStorage]; ok {
+		return &val
+	}
+	return &resource.Quantity{}
+}

vendor/k8s.io/api/core/v1/taint.go

@@ -0,0 +1,33 @@
+/*
+Copyright 2017 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package v1
+
+import "fmt"
+
+// MatchTaint checks if the taint matches taintToMatch. Taints are unique by key:effect,
+// if the two taints have same key:effect, regard as they match.
+func (t *Taint) MatchTaint(taintToMatch *Taint) bool {
+	return t.Key == taintToMatch.Key && t.Effect == taintToMatch.Effect
+}
+
+// taint.ToString() converts taint struct to string in format key=value:effect or key:effect.
+func (t *Taint) ToString() string {
+	if len(t.Value) == 0 {
+		return fmt.Sprintf("%v:%v", t.Key, t.Effect)
+	}
+	return fmt.Sprintf("%v=%v:%v", t.Key, t.Value, t.Effect)
+}

vendor/k8s.io/api/core/v1/toleration.go

@@ -0,0 +1,56 @@
+/*
+Copyright 2017 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package v1
+
+// MatchToleration checks if the toleration matches tolerationToMatch. Tolerations are unique by <key,effect,operator,value>,
+// if the two tolerations have same <key,effect,operator,value> combination, regard as they match.
+// TODO: uniqueness check for tolerations in api validations.
+func (t *Toleration) MatchToleration(tolerationToMatch *Toleration) bool {
+	return t.Key == tolerationToMatch.Key &&
+		t.Effect == tolerationToMatch.Effect &&
+		t.Operator == tolerationToMatch.Operator &&
+		t.Value == tolerationToMatch.Value
+}
+
+// ToleratesTaint checks if the toleration tolerates the taint.
+// The matching follows the rules below:
+// (1) Empty toleration.effect means to match all taint effects,
+//     otherwise taint effect must equal to toleration.effect.
+// (2) If toleration.operator is 'Exists', it means to match all taint values.
+// (3) Empty toleration.key means to match all taint keys.
+//     If toleration.key is empty, toleration.operator must be 'Exists';
+//     this combination means to match all taint values and all taint keys.
+func (t *Toleration) ToleratesTaint(taint *Taint) bool {
+	if len(t.Effect) > 0 && t.Effect != taint.Effect {
+		return false
+	}
+
+	if len(t.Key) > 0 && t.Key != taint.Key {
+		return false
+	}
+
+	// TODO: Use proper defaulting when Toleration becomes a field of PodSpec
+	switch t.Operator {
+	// empty operator means Equal
+	case "", TolerationOpEqual:
+		return t.Value == taint.Value
+	case TolerationOpExists:
+		return true
+	default:
+		return false
+	}
+}