refactor: Move from global state to functions

This commit represents a few experiments of features I've used in Cobra

1. Uses cli.GenericFlag to encapsulate parsing and validation of flag
   values at parse time. This removes the burden from the individual
   CLI commands to parse and validate args and options.

2. Add flag.ID that may be used by any flag that requires an Influx ID.
   flag.ID parses and validates string value is a valid ID, removing
   this burden from individual commands and ensuring valid values before
   the command actions begins.

3. Adds a Flags() method to the Params structs to directly capture
   the values when parsing flags.

4. Moves from global state to local builder functions for the majority
   of the commands. This allows the commands to bind to flag variables
   reducing the repeated ctx.String(), ctx.Int(), etc

5. Leverages the BeforeFunc to create middleware and inject the CLI and
   API client into commands, saving the repeated boilerplate across
   all of the instantiated commands. This is extensible, so additional
   middleware can be appends using the middleware.WithBeforeFns

cmd/influx/bucket.go

@@ -2,223 +2,101 @@ package main
 
 import (
 	"github.com/influxdata/influx-cli/v2/internal"
+	"github.com/influxdata/influx-cli/v2/pkg/cmd/middleware"
 	"github.com/urfave/cli/v2"
 )
 
-var bucketCmd = cli.Command{
-	Name:  "bucket",
-	Usage: "Bucket management commands",
-	Subcommands: []*cli.Command{
-		{
-			Name:  "create",
-			Usage: "Create bucket",
-			Flags: append(
-				commonFlags,
-				&cli.StringFlag{
-					Name:     "name",
-					Usage:    "New bucket name",
-					Aliases:  []string{"n"},
-					EnvVars:  []string{"INFLUX_BUCKET_NAME"},
-					Required: true,
-				},
-				&cli.StringFlag{
-					Name:    "description",
-					Usage:   "Description of the bucket that will be created",
-					Aliases: []string{"d"},
-				},
-				&cli.StringFlag{
-					Name:        "retention",
-					Usage:       "Duration bucket will retain data, or 0 for infinite",
-					Aliases:     []string{"r"},
-					DefaultText: "infinite",
-				},
-				&cli.StringFlag{
-					Name:        "shard-group-duration",
-					Usage:       "Shard group duration used internally by the storage engine",
-					DefaultText: "calculated from retention",
-				},
-				&cli.StringFlag{
-					Name:    "org-id",
-					Usage:   "The ID of the organization",
-					EnvVars: []string{"INFLUX_ORG_ID"},
-				},
-				&cli.StringFlag{
-					Name:    "org",
-					Usage:   "The name of the organization",
-					Aliases: []string{"o"},
-					EnvVars: []string{"INFLUX_ORG"},
-				},
-			),
-			Action: func(ctx *cli.Context) error {
-				cli, err := newCli(ctx)
-				if err != nil {
-					return err
-				}
-				client, err := newApiClient(ctx, cli, true)
-				if err != nil {
-					return err
-				}
-				clients := internal.BucketsClients{
-					BucketApi: client.BucketsApi,
-					OrgApi:    client.OrganizationsApi,
-				}
-				return cli.BucketsCreate(standardCtx(ctx), &clients, &internal.BucketsCreateParams{
-					OrgID:              ctx.String("org-id"),
-					OrgName:            ctx.String("org"),
-					Name:               ctx.String("name"),
-					Description:        ctx.String("description"),
-					Retention:          ctx.String("retention"),
-					ShardGroupDuration: ctx.String("shard-group-duration"),
-				})
-			},
+func withBucketsClient() cli.BeforeFunc {
+	return middleware.WithBeforeFns(
+		withCli(),
+		withApi(),
+		func(ctx *cli.Context) error {
+			client := getAPI(ctx)
+			ctx.App.Metadata["bucketsClient"] = internal.BucketsClients{
+				BucketApi: client.BucketsApi,
+				OrgApi:    client.OrganizationsApi,
+			}
+			return nil
 		},
-		{
-			Name:  "delete",
-			Usage: "Delete bucket",
-			Flags: append(
-				commonFlags,
-				&cli.StringFlag{
-					Name:    "id",
-					Usage:   "The bucket ID, required if name isn't provided",
-					Aliases: []string{"i"},
-				},
-				&cli.StringFlag{
-					Name:    "name",
-					Usage:   "The bucket name, org or org-id will be required by choosing this",
-					Aliases: []string{"n"},
-				},
-				&cli.StringFlag{
-					Name:    "org-id",
-					Usage:   "The ID of the organization",
-					EnvVars: []string{"INFLUX_ORG_ID"},
-				},
-				&cli.StringFlag{
-					Name:    "org",
-					Usage:   "The name of the organization",
-					Aliases: []string{"o"},
-					EnvVars: []string{"INFLUX_ORG"},
-				},
-			),
-			Action: func(ctx *cli.Context) error {
-				cli, err := newCli(ctx)
-				if err != nil {
-					return err
-				}
-				client, err := newApiClient(ctx, cli, true)
-				if err != nil {
-					return err
-				}
-				clients := internal.BucketsClients{
-					BucketApi: client.BucketsApi,
-					OrgApi:    client.OrganizationsApi,
-				}
-				return cli.BucketsDelete(standardCtx(ctx), &clients, &internal.BucketsDeleteParams{
-					ID:      ctx.String("id"),
-					Name:    ctx.String("name"),
-					OrgID:   ctx.String("org-id"),
-					OrgName: ctx.String("org"),
-				})
-			},
+	)
+}
+
+func getBucketsClient(ctx *cli.Context) internal.BucketsClients {
+	i, ok := ctx.App.Metadata["bucketsClient"].(internal.BucketsClients)
+	if !ok {
+		panic("missing buckets client")
+	}
+	return i
+}
+
+func newBucketCmd() *cli.Command {
+	return &cli.Command{
+		Name:  "bucket",
+		Usage: "Bucket management commands",
+		Subcommands: []*cli.Command{
+			newBucketCreateCmd(),
+			newBucketDeleteCmd(),
+			newBucketListCmd(),
+			newBucketUpdateCmd(),
 		},
-		{
-			Name:    "list",
-			Usage:   "List buckets",
-			Aliases: []string{"find", "ls"},
-			Flags: append(
-				commonFlags,
-				&cli.StringFlag{
-					Name:    "name",
-					Usage:   "The bucket name",
-					Aliases: []string{"n"},
-					EnvVars: []string{"INFLUX_BUCKET_NAME"},
-				},
-				&cli.StringFlag{
-					Name:    "org-id",
-					Usage:   "The ID of the organization",
-					EnvVars: []string{"INFLUX_ORG_ID"},
-				},
-				&cli.StringFlag{
-					Name:    "org",
-					Usage:   "The name of the organization",
-					Aliases: []string{"o"},
-					EnvVars: []string{"INFLUX_ORG"},
-				},
-				&cli.StringFlag{
-					Name:    "id",
-					Usage:   "The bucket ID",
-					Aliases: []string{"i"},
-				},
-			),
-			Action: func(ctx *cli.Context) error {
-				cli, err := newCli(ctx)
-				if err != nil {
-					return err
-				}
-				client, err := newApiClient(ctx, cli, true)
-				if err != nil {
-					return err
-				}
-				clients := internal.BucketsClients{
-					BucketApi: client.BucketsApi,
-					OrgApi:    client.OrganizationsApi,
-				}
-				return cli.BucketsList(standardCtx(ctx), &clients, &internal.BucketsListParams{
-					ID:      ctx.String("id"),
-					Name:    ctx.String("name"),
-					OrgID:   ctx.String("org-id"),
-					OrgName: ctx.String("org"),
-				})
-			},
+	}
+
+}
+
+func newBucketCreateCmd() *cli.Command {
+	var params internal.BucketsCreateParams
+	return &cli.Command{
+		Name:   "create",
+		Usage:  "Create bucket",
+		Before: withBucketsClient(),
+		Flags:  append(commonFlags, params.Flags()...),
+		Action: func(ctx *cli.Context) error {
+			clients := getBucketsClient(ctx)
+			return getCLI(ctx).BucketsCreate(ctx.Context, &clients, &params)
 		},
-		{
-			Name:  "update",
-			Usage: "Update bucket",
-			Flags: append(
-				commonFlags,
-				&cli.StringFlag{
-					Name:    "name",
-					Usage:   "New name to set on the bucket",
-					Aliases: []string{"n"},
-					EnvVars: []string{"INFLUX_BUCKET_NAME"},
-				},
-				&cli.StringFlag{
-					Name:     "id",
-					Usage:    "The bucket ID",
-					Aliases:  []string{"i"},
-					Required: true,
-				},
-				&cli.StringFlag{
-					Name:    "description",
-					Usage:   "New description to set on the bucket",
-					Aliases: []string{"d"},
-				},
-				&cli.StringFlag{
-					Name:    "retention",
-					Usage:   "New retention duration to set on the bucket, or 0 for infinite",
-					Aliases: []string{"r"},
-				},
-				&cli.StringFlag{
-					Name:  "shard-group-duration",
-					Usage: "New shard group duration to set on the bucket, or 0 to have the server calculate a value",
-				},
-			),
-			Action: func(ctx *cli.Context) error {
-				cli, err := newCli(ctx)
-				if err != nil {
-					return err
-				}
-				client, err := newApiClient(ctx, cli, true)
-				if err != nil {
-					return err
-				}
-				return cli.BucketsUpdate(standardCtx(ctx), client.BucketsApi, &internal.BucketsUpdateParams{
-					ID:                 ctx.String("id"),
-					Name:               ctx.String("name"),
-					Description:        ctx.String("description"),
-					Retention:          ctx.String("retention"),
-					ShardGroupDuration: ctx.String("shard-group-duration"),
-				})
-			},
+	}
+}
+
+func newBucketDeleteCmd() *cli.Command {
+	var params internal.BucketsDeleteParams
+	return &cli.Command{
+		Name:   "delete",
+		Usage:  "Delete bucket",
+		Before: withBucketsClient(),
+		Flags:  append(commonFlags, params.Flags()...),
+		Action: func(ctx *cli.Context) error {
+			clients := getBucketsClient(ctx)
+			return getCLI(ctx).BucketsDelete(ctx.Context, &clients, &params)
+		},
+	}
+}
+
+func newBucketListCmd() *cli.Command {
+	var params internal.BucketsListParams
+	return &cli.Command{
+		Name:    "list",
+		Usage:   "List buckets",
+		Aliases: []string{"find", "ls"},
+		Before:  withBucketsClient(),
+		Flags:   append(commonFlags, params.Flags()...),
+		Action: func(ctx *cli.Context) error {
+			clients := getBucketsClient(ctx)
+			return getCLI(ctx).BucketsList(ctx.Context, &clients, &params)
+		},
+	}
+}
+
+func newBucketUpdateCmd() *cli.Command {
+	var params internal.BucketsUpdateParams
+	return &cli.Command{
+		Name:    "update",
+		Usage:   "Update bucket",
+		Aliases: []string{"find", "ls"},
+		Before:  withBucketsClient(),
+		Flags:   append(commonFlags, params.Flags()...),
+		Action: func(ctx *cli.Context) error {
+			clients := getBucketsClient(ctx)
+			return getCLI(ctx).BucketsUpdate(ctx.Context, clients.BucketApi, &params)
 		},
-	},
+	}
 }