[ENHANCEMENT] cue/common: provide new standard definitions for datasource plugins

Signed-off-by: AntoineThebaud <antoine.thebaud@yahoo.fr>

Author: AntoineThebaud

cue-test/common/datasource.cue

@@ -0,0 +1,43 @@
+// Copyright The Perses 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 common
+
+myDirectSpec: {
+	common.#baseDatasourceSpec
+	directUrl: "localhost:8080"
+}
+
+myProxySpec: {
+	common.#baseDatasourceSpec
+	proxy: {
+		kind: "HTTPProxy",
+		spec: {
+			url: "https://prometheus.demo.prometheus.io",
+			allowedEndpoints: [
+				{
+				endpointPattern: "/api/v1/labels",
+				method: "POST"
+				},
+				{
+				endpointPattern: "/api/v1/series",
+				method: "POST"
+				},
+			]
+		}
+	},
+}
+
+myDsVarSelector: #datasourceSelector & { _kind: "MyDatasource" }
+
+myDsVarSelector: #datasourceSelector & { datasource: "$dsVar" }

cue-test/common/format.cue

@@ -14,6 +14,6 @@
 package common
 
 myFormat: #format & {
-    decimalPlaces: 0
-    shortValues:   false
+	decimalPlaces: 0
+	shortValues:   false
 }

cue/common/datasource.cue

@@ -13,9 +13,20 @@
 
 package common
 
+#baseDatasourceSpec: #directUrl | #proxy
+
+#directUrl: {
+	directUrl: common.#url
+}
+
+#proxy: {
+	proxy: commonProxy.#HTTPProxy
+}
+
 #datasourceSelector: {
+	_kind: string
 	datasource?: =~#variableSyntaxRegex | {
-		kind:  string
+		kind:  _kind
 		name?: string
 	}
-}
+}