Extract commonly-used flags for reuse

commands/flags/duration.go

+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You 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 flags
+
+import (
+	"github.com/apache/skywalking-cli/commands/model"
+	"github.com/apache/skywalking-cli/graphql/schema"
+	"github.com/urfave/cli"
+)
+
+// DurationFlags are common flags that involves a duration, composed
+// by a start time, an end time, and a step, which is commonly used
+// in most of the commands
+var DurationFlags = []cli.Flag{
+	cli.StringFlag{
+		Name:  "start",
+		Usage: "query start `TIME`",
+	},
+	cli.StringFlag{
+		Name:  "end",
+		Usage: "query end `TIME`",
+	},
+	cli.GenericFlag{
+		Name:   "step",
+		Hidden: true,
+		Value: &model.StepEnumValue{
+			Enum:     schema.AllStep,
+			Default:  schema.StepMinute,
+			Selected: schema.StepMinute,
+		},
+	},
+}

commands/service/list.go

@@ -21,6 +21,7 @@ package service
 import (
 	"encoding/json"
 	"fmt"
+	"github.com/apache/skywalking-cli/commands/flags"
 	"github.com/apache/skywalking-cli/commands/interceptor"
 	"github.com/apache/skywalking-cli/commands/model"
 	"github.com/apache/skywalking-cli/graphql/client"
@@ -32,25 +33,7 @@ var ListCommand = cli.Command{
 	Name:      "list",
 	ShortName: "ls",
 	Usage:     "List all available services",
-	Flags: []cli.Flag{
-		cli.StringFlag{
-			Name:  "start",
-			Usage: "query start `TIME`",
-		},
-		cli.StringFlag{
-			Name:  "end",
-			Usage: "query end `TIME`",
-		},
-		cli.GenericFlag{
-			Name:   "step",
-			Hidden: true,
-			Value: &model.StepEnumValue{
-				Enum:     schema.AllStep,
-				Default:  schema.StepMinute,
-				Selected: schema.StepMinute,
-			},
-		},
-	},
+	Flags:     flags.DurationFlags,
 	Before: interceptor.BeforeChain([]cli.BeforeFunc{
 		interceptor.DurationInterceptor,
 	}),