refactor: removed cobra in favour of urfave/cli

cmd/fl/main.go

@@ -4,27 +4,18 @@ import (
 	"context"
 	"log"
 	"math/rand"
+	"os"
 	"time"
 
-	"github.com/spf13/cobra"
-	"github.com/spf13/viper"
-
 	"github.com/weaveworks-experiments/fl/internal/cmd"
 )
 
 func main() {
 	rand.Seed(time.Now().UnixNano())
 	ctx := context.Background()
 
-	cobra.OnInitialize(initConfig)
-
-	rootCmd := cmd.NewRootCmd()
-	if err := rootCmd.ExecuteContext(ctx); err != nil {
-		log.Fatal("failed executing root command")
+	app := cmd.NewApp()
+	if err := app.RunContext(ctx, os.Args); err != nil {
+		log.Fatalf("failed executing root command: %s", err)
 	}
 }
-
-func initConfig() {
-	viper.SetEnvPrefix("FL")
-	viper.AutomaticEnv()
-}

go.mod

@@ -4,36 +4,28 @@ go 1.17
 
 require (
 	github.com/moby/moby v20.10.14+incompatible
-	github.com/spf13/cobra v1.4.0
-	github.com/spf13/pflag v1.0.5
-	github.com/spf13/viper v1.10.1
+	github.com/urfave/cli/v2 v2.4.0
 	github.com/weaveworks/flintlock/api v0.0.0-20220304105853-8fcb8aa2bafb
 	github.com/weaveworks/flintlock/client v0.0.0-20220304105853-8fcb8aa2bafb
 	github.com/yitsushi/macpot v1.0.2
 	go.uber.org/zap v1.21.0
-	google.golang.org/grpc v1.44.0
+	google.golang.org/grpc v1.45.0
 	gopkg.in/yaml.v2 v2.4.0
 )
 
 require (
-	github.com/fsnotify/fsnotify v1.5.1 // indirect
+	github.com/cpuguy83/go-md2man/v2 v2.0.1 // indirect
 	github.com/golang/protobuf v1.5.2 // indirect
+	github.com/google/go-cmp v0.5.7 // indirect
 	github.com/grpc-ecosystem/grpc-gateway/v2 v2.6.0 // indirect
-	github.com/hashicorp/hcl v1.0.0 // indirect
-	github.com/inconshreveable/mousetrap v1.0.0 // indirect
-	github.com/magiconair/properties v1.8.6 // indirect
-	github.com/mitchellh/mapstructure v1.4.3 // indirect
-	github.com/pelletier/go-toml v1.9.4 // indirect
-	github.com/spf13/afero v1.8.2 // indirect
-	github.com/spf13/cast v1.4.1 // indirect
-	github.com/spf13/jwalterweatherman v1.1.0 // indirect
-	github.com/subosito/gotenv v1.2.0 // indirect
+	github.com/russross/blackfriday/v2 v2.1.0 // indirect
+	github.com/stretchr/testify v1.7.1 // indirect
 	go.uber.org/atomic v1.9.0 // indirect
 	go.uber.org/multierr v1.8.0 // indirect
-	golang.org/x/net v0.0.0-20211209124913-491a49abca63 // indirect
-	golang.org/x/sys v0.0.0-20220405210540-1e041c57c461 // indirect
+	golang.org/x/net v0.0.0-20220412020605-290c469a71a5 // indirect
+	golang.org/x/sys v0.0.0-20220412211240-33da011f77ad // indirect
 	golang.org/x/text v0.3.7 // indirect
-	google.golang.org/genproto v0.0.0-20211208223120-3a66f561d7aa // indirect
+	golang.org/x/xerrors v0.0.0-20220411194840-2f41105eb62f // indirect
+	google.golang.org/genproto v0.0.0-20220407144326-9054f6ed7bac // indirect
 	google.golang.org/protobuf v1.28.0 // indirect
-	gopkg.in/ini.v1 v1.66.4 // indirect
 )

internal/cmd/app.go

@@ -0,0 +1,44 @@
+package cmd
+
+import (
+	"github.com/urfave/cli/v2"
+
+	"github.com/weaveworks-experiments/fl/internal/cmd/microvm"
+	"github.com/weaveworks-experiments/fl/pkg/logging"
+)
+
+const (
+	logLevelFlag = "log-level"
+)
+
+func NewApp() *cli.App {
+	app := &cli.App{
+		Name:     "fl",
+		Usage:    "The experimental cli for flintlock",
+		Commands: []*cli.Command{},
+		Flags: []cli.Flag{
+			&cli.StringFlag{
+				Name:  logLevelFlag,
+				Usage: "set the level of the debugger",
+				Value: "debug",
+			},
+		},
+		Before: func(ctx *cli.Context) error {
+			logLevelFlag := ctx.String(logLevelFlag)
+			err := logging.Configure(logLevelFlag)
+			if err != nil {
+				return err
+			}
+
+			return nil
+		},
+	}
+
+	versionCmd := newVersionCommand()
+	app.Commands = append(app.Commands, versionCmd)
+
+	microvmCmd := microvm.NewCommand()
+	app.Commands = append(app.Commands, microvmCmd)
+
+	return app
+}

internal/cmd/microvm/create.go

@@ -1,12 +1,13 @@
 package microvm
 
 import (
-	"github.com/moby/moby/pkg/namesgenerator"
-	"github.com/spf13/cobra"
+	"errors"
+	"fmt"
+
+	"github.com/urfave/cli/v2"
 	"go.uber.org/zap"
 
 	"github.com/weaveworks-experiments/fl/pkg/app"
-	"github.com/weaveworks-experiments/fl/pkg/flags"
 )
 
 const (
@@ -18,44 +19,137 @@ const (
 	defaultRootImage   = "ghcr.io/weaveworks/capmvm-kubernetes:1.21.8"
 )
 
-func newCreateCommand() *cobra.Command {
+func newCreateCommand() *cli.Command {
 	createInput := &app.CreateInput{}
+	networkInterfaces := &cli.StringSlice{}
+	metadataFromFile := &cli.StringSlice{}
+
+	cmd := &cli.Command{
+		Name:  "create",
+		Usage: "create a new microvm",
+		Before: func(ctx *cli.Context) error {
+			if createInput.Name != "" && createInput.NameAutogenerate {
+				return errors.New("only one of --name or --name-autoegenarate can be specified")
+			}
+
+			if createInput.Name == "" && !createInput.NameAutogenerate {
+				return errors.New("you must supply one of --name or --name-autoegenarate")
+			}
 
-	cmd := &cobra.Command{
-		Use:   "create",
-		Short: "create a new microvm",
-		PreRun: func(cmd *cobra.Command, args []string) {
-			flags.BindFlags(cmd)
+			return nil
 		},
-		Run: func(c *cobra.Command, _ []string) {
+		Action: func(ctx *cli.Context) error {
 			a := app.New(zap.S().With("action", "create"))
-			if err := a.Create(c.Context(), createInput); err != nil {
-				zap.S().Errorw("failed creating microvm", "error", err)
+			if err := a.Create(ctx.Context, createInput); err != nil {
+				return fmt.Errorf("creating microvm: %s", err)
 			}
+
+			return nil
+		},
+		Flags: []cli.Flag{
+			&cli.StringFlag{
+				Name:        "host",
+				Usage:       "the flintlock host to create the microvm on",
+				Destination: &createInput.Host,
+				Required:    true,
+			},
+			&cli.StringFlag{
+				Name:        "name",
+				Usage:       "the name of the microvm, cannot be specified if using name-autogenerate",
+				Destination: &createInput.Name,
+			},
+			&cli.BoolFlag{
+				Name:        "name-autogenerate",
+				Usage:       "if true a name is autogenerated for the microvm",
+				Value:       false,
+				Destination: &createInput.NameAutogenerate,
+			},
+			&cli.StringFlag{
+				Name:        "namespace",
+				Usage:       "the namespace for the microvm",
+				Destination: &createInput.Namespace,
+				Value:       defaultNamespace,
+			},
+			&cli.IntFlag{
+				Name:        "vcpu",
+				Usage:       "the number of vcpus",
+				Value:       defaultVCPU,
+				Destination: &createInput.VCPU,
+			},
+			&cli.IntFlag{
+				Name:        "memory",
+				Usage:       "the memory in mb",
+				Value:       defaultMemoryMb,
+				Destination: &createInput.MemoryInMb,
+			},
+			&cli.StringFlag{
+				Name:        "kernel-image",
+				Usage:       "the image to use for the kernel",
+				Destination: &createInput.KernelImage,
+				Value:       defaultKernelImage,
+			},
+			&cli.BoolFlag{
+				Name:        "add-netconf",
+				Usage:       "automatically add network configuration to the kernel cmd line",
+				Destination: &createInput.KernelAddNetConf,
+				Value:       true,
+			},
+			&cli.StringFlag{
+				Name:        "kernel-filename",
+				Usage:       "name of the kernel file in the image",
+				Destination: &createInput.KernelFileName,
+				Value:       defaultKernelFile,
+			},
+			&cli.StringFlag{
+				Name:        "root-image",
+				Usage:       "the image to use for the root volume",
+				Destination: &createInput.RootImage,
+				Value:       defaultRootImage,
+			},
+			&cli.StringFlag{
+				Name:        "initrd-image",
+				Usage:       "the image to use for the initial ramdisk",
+				Destination: &createInput.InitrdImage,
+			},
+			&cli.StringFlag{
+				Name:        "initrd-filename",
+				Usage:       "name of the file in the image to use for the initial ramdisk",
+				Destination: &createInput.InitrdFilename,
+			},
+			&cli.StringSliceFlag{
+				Name:        "network-interface",
+				Usage:       "specify the network interfaces to attach. In the following format: name:type:[macaddress]:[ipaddress]",
+				Destination: networkInterfaces,
+			},
+			&cli.StringSliceFlag{
+				Name:        "metadata-from-file",
+				Usage:       "specify metadata to be available to your microvm. In the following format key=pathtofile",
+				Destination: metadataFromFile,
+			},
+			&cli.StringFlag{
+				Name:        "metadata-hostname",
+				Usage:       "the hostname of the the microvm",
+				Destination: &createInput.Metadata.Hostname,
+			},
+			&cli.StringFlag{
+				Name:        "metadata-ssh-key-file",
+				Usage:       "an ssh key to use",
+				Destination: &createInput.Metadata.SSHKeyFile,
+			},
+			&cli.BoolFlag{
+				Name:        "metadata-resolvd-fix",
+				Usage:       "include a systemd-resolvd fix for container root volumes",
+				Destination: &createInput.Metadata.ResolvdFix,
+				Value:       true,
+			},
+			&cli.StringFlag{
+				Name:        "metadata-final-message",
+				Usage:       "set the cloud-init final message",
+				Destination: &createInput.Metadata.Message,
+			},
 		},
 	}
 
-	cmd.Flags().StringVar(&createInput.Host, "host", "", "the flintlock host to create the microvm on")
-	cmd.MarkFlagRequired("host")
-
-	defaultName := namesgenerator.GetRandomName(10)
-	cmd.Flags().StringVar(&createInput.Name, "name", defaultName, "the name of the microvm, auto-generated if not supplied")
-	cmd.Flags().StringVar(&createInput.Namespace, "namespace", defaultNamespace, "the namespace for the microvm")
-	cmd.Flags().IntVar(&createInput.VCPU, "vcpu", defaultVCPU, "the number of vcpus")
-	cmd.Flags().IntVar(&createInput.MemoryInMb, "memory", defaultMemoryMb, "the memory in mb")
-	cmd.Flags().StringVar(&createInput.KernelImage, "kernel-image", defaultKernelImage, "the image to use for the kernel")
-	cmd.Flags().BoolVar(&createInput.KernelAddNetConf, "add-netconf", true, "automatically add network configuration to the kernel cmd line")
-	cmd.Flags().StringVar(&createInput.KernelFileName, "kernel-filename", defaultKernelFile, "name of the kernel file in the image")
-	cmd.Flags().StringVar(&createInput.RootImage, "root-image", defaultRootImage, "the image to use for the root volume")
-	cmd.Flags().StringVar(&createInput.InitrdImage, "initrd-image", "", "the image to use for the initial ramdisk")
-	cmd.Flags().StringVar(&createInput.InitrdFilename, "initrd-filename", "", "name of the file in the image to use for the initial ramdisk")
-	cmd.Flags().StringSliceVar(&createInput.NetworkInterfaces, "network-interface", nil, "specify the network interfaces to attach. In the following format: name:type:[macaddress]:[ipaddress]")
-	cmd.Flags().StringSliceVar(&createInput.MetadataFromFile, "metadata-from-file", nil, "specify metadata to be available to your microvm. In the following format key=pathtofile")
-	cmd.Flags().StringVar(&createInput.Metadata.Hostname, "metadata-hostname", "", "the hostname of the the microvm")
-	cmd.Flags().StringVar(&createInput.Metadata.SSHKeyFile, "metadata-ssh-key-file", "", "an ssh key to use")
-	cmd.Flags().BoolVar(&createInput.Metadata.ResolvdFix, "metadata-resolvd-fix", true, "include a systemd-resolvd fix for container root volumes")
-	cmd.Flags().StringVar(&createInput.Metadata.Message, "metadata-final-message", "", "set the cloud-init final message")
-
 	//TODO: additional command line args for kernel
 	//TODO: add additional volumes
 

internal/cmd/microvm/delete.go

@@ -1,11 +1,13 @@
 package microvm
 
 import (
-	"github.com/spf13/cobra"
+	"errors"
+	"fmt"
+
+	"github.com/urfave/cli/v2"
 	"go.uber.org/zap"
 
 	"github.com/weaveworks-experiments/fl/pkg/app"
-	"github.com/weaveworks-experiments/fl/pkg/flags"
 )
 
 const (
@@ -15,31 +17,35 @@ fl microvm delete --host host1:9090 01FZZJV1XD2FKH2KY0NDB4MBRQ
 `
 )
 
-func newDeleteCommand() *cobra.Command {
+func newDeleteCommand() *cli.Command {
 	deleteInput := &app.DeleteInput{}
 
-	cmd := &cobra.Command{
-		Use:     "delete",
-		Short:   "delete a microvm from a host",
-		Example: deleteExamples,
-		Args:    cobra.ExactValidArgs(1),
-		PreRun: func(cmd *cobra.Command, args []string) {
-			flags.BindFlags(cmd)
-		},
-		Run: func(c *cobra.Command, args []string) {
-			deleteInput.UID = args[0]
+	cmd := &cli.Command{
+		Name:  "delete",
+		Usage: "delete a microvm from a host",
+		Action: func(ctx *cli.Context) error {
+			if ctx.Args().Len() == 0 {
+				return errors.New("you must supply the uid as an argument")
+			}
+			deleteInput.UID = ctx.Args().Get(0)
 
 			a := app.New(zap.S().With("action", "delete"))
-			err := a.Delete(c.Context(), deleteInput)
+			err := a.Delete(ctx.Context, deleteInput)
 			if err != nil {
-				zap.S().Errorw("failed deleting microvm", "error", err)
-				return
+				return fmt.Errorf("deleting microvm: %w", err)
 			}
+
+			return nil
+		},
+		Flags: []cli.Flag{
+			&cli.StringFlag{
+				Name:        "host",
+				Usage:       "the flintlock host to delete the microvm on",
+				Destination: &deleteInput.Host,
+				Required:    true,
+			},
 		},
 	}
 
-	cmd.Flags().StringVar(&deleteInput.Host, "host", "", "the flintlock host to get the microvms from")
-	cmd.MarkFlagRequired("host")
-
 	return cmd
 }