Adding Source ducktype. (knative#566)

* Adding Source ducktype.

* removing output format for now, revisit if we find more sources and consumers asking for it.

apis/duck/v1beta1/source_types.go

@@ -0,0 +1,157 @@
+/*
+Copyright 2019 The Knative 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 v1beta1
+
+import (
+	"time"
+
+	corev1 "k8s.io/api/core/v1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/runtime"
+
+	"knative.dev/pkg/apis"
+	"knative.dev/pkg/apis/duck"
+	apisv1alpha1 "knative.dev/pkg/apis/v1alpha1"
+)
+
+// Source is an Implementable "duck type".
+var _ duck.Implementable = (*Source)(nil)
+
+// +genclient
+// +k8s:deepcopy-gen:interfaces=k8s.io/apimachinery/pkg/runtime.Object
+
+// Source is the minimum resource shape to adhere to the Source Specification.
+// This duck type is intended to allow implementors of Sources and
+// Importers to verify their own resources meet the expectations.
+// This is not a real resource.
+// NOTE: The Source Specification is in progress and the shape and names could
+// be modified until it has been accepted.
+type Source struct {
+	metav1.TypeMeta   `json:",inline"`
+	metav1.ObjectMeta `json:"metadata,omitempty"`
+
+	Spec   SourceSpec   `json:"spec"`
+	Status SourceStatus `json:"status"`
+}
+
+type SourceSpec struct {
+	// Sink is a reference to an object that will resolve to a domain name or a
+	// URI directly to use as the sink.
+	Sink apisv1alpha1.Destination `json:"sink,omitempty"`
+
+	// CloudEventOverrides defines overrides to control the output format and
+	// modifications of the event sent to the sink.
+	// +optional
+	CloudEventOverrides *CloudEventOverrides `json:"ceOverrides,omitempty"`
+}
+
+// CloudEventOverrides defines arguments for a Source that control the output
+// format of the CloudEvents produced by the Source.
+type CloudEventOverrides struct {
+	// Extensions specify what attribute are added or overridden on the
+	// outbound event. Each `Extensions` key-value pair are set on the event as
+	// an attribute extension independently.
+	// +optional
+	Extensions map[string]string `json:"extensions,omitempty"`
+}
+
+// SourceStatus shows how we expect folks to embed Addressable in
+// their Status field.
+type SourceStatus struct {
+	// inherits duck/v1beta1 Status, which currently provides:
+	// * ObservedGeneration - the 'Generation' of the Service that was last
+	//   processed by the controller.
+	// * Conditions - the latest available observations of a resource's current
+	//   state.
+	Status `json:",inline"`
+
+	// SinkURI is the current active sink URI that has been configured for the
+	// Source.
+	// +optional
+	SinkURI *apis.URL `json:"sinkUri,omitempty"`
+}
+
+// IsReady returns true if the resource is ready overall.
+func (ss *SourceStatus) IsReady() bool {
+	for _, c := range ss.Conditions {
+		switch c.Type {
+		// Look for the "happy" condition, which is the only condition that
+		// we can reliably understand to be the overall state of the resource.
+		case apis.ConditionReady, apis.ConditionSucceeded:
+			return c.IsTrue()
+		}
+	}
+	return false
+}
+
+var (
+	// Verify Source resources meet duck contracts.
+	_ duck.Populatable = (*Source)(nil)
+	_ apis.Listable    = (*Source)(nil)
+)
+
+const (
+	// SourceConditionSinkProvided has status True when the Source
+	// has been configured with a sink target that is resolvable.
+	SourceConditionSinkProvided apis.ConditionType = "SinkProvided"
+)
+
+// GetFullType implements duck.Implementable
+func (*Source) GetFullType() duck.Populatable {
+	return &Source{}
+}
+
+// Populate implements duck.Populatable
+func (s *Source) Populate() {
+	s.Spec.Sink = apisv1alpha1.Destination{
+		URI: &apis.URL{
+			Scheme:   "https",
+			Host:     "tableflip.dev",
+			RawQuery: "flip=mattmoor",
+		},
+	}
+	s.Spec.CloudEventOverrides = &CloudEventOverrides{
+		Extensions: map[string]string{"boosh": "kakow"},
+	}
+	s.Status.ObservedGeneration = 42
+	s.Status.Conditions = Conditions{{
+		// Populate ALL fields
+		Type:               SourceConditionSinkProvided,
+		Status:             corev1.ConditionTrue,
+		LastTransitionTime: apis.VolatileTime{Inner: metav1.NewTime(time.Date(1984, 02, 28, 18, 52, 00, 00, time.UTC))},
+	}}
+	s.Status.SinkURI = &apis.URL{
+		Scheme:   "https",
+		Host:     "tableflip.dev",
+		RawQuery: "flip=mattmoor",
+	}
+}
+
+// GetListType implements apis.Listable
+func (*Source) GetListType() runtime.Object {
+	return &SourceList{}
+}
+
+// +k8s:deepcopy-gen:interfaces=k8s.io/apimachinery/pkg/runtime.Object
+
+// SourceList is a list of Source resources
+type SourceList struct {
+	metav1.TypeMeta `json:",inline"`
+	metav1.ListMeta `json:"metadata"`
+
+	Items []Source `json:"items"`
+}