(#1145) Support interactive edit for consumers

Here we add the --interactive flag to the consumer edit action. This
behaves the same as stream interactive edit.

cli/consumer_command.go

@@ -22,6 +22,7 @@ import (
 	"math"
 	"math/rand"
 	"os"
+	"os/exec"
 	"os/signal"
 	"regexp"
 	"sort"
@@ -33,6 +34,7 @@ import (
 	"github.com/nats-io/natscli/columns"
 	iu "github.com/nats-io/natscli/internal/util"
 	terminal "golang.org/x/term"
+	"gopkg.in/yaml.v3"
 
 	"github.com/AlecAivazis/survey/v2"
 	"github.com/choria-io/fisk"
@@ -116,6 +118,7 @@ type consumerCmd struct {
 	fInvert     bool
 	fExpression string
 	fLeader     string
+	interactive bool
 }
 
 func configureConsumerCommand(app commandHost) {
@@ -190,6 +193,7 @@ func configureConsumerCommand(app commandHost) {
 	edit.Arg("consumer", "Consumer name").StringVar(&c.consumer)
 	edit.Flag("config", "JSON file to read configuration from").ExistingFileVar(&c.inputFile)
 	edit.Flag("force", "Force removal without prompting").Short('f').UnNegatableBoolVar(&c.force)
+	edit.Flag("interactive", "Edit the configuring using your editor").Short('i').BoolVar(&c.interactive)
 	edit.Flag("dry-run", "Only shows differences, do not edit the stream").UnNegatableBoolVar(&c.dryRun)
 	addCreateFlags(edit, true)
 
@@ -556,108 +560,173 @@ func (c *consumerCmd) leaderStandDownAction(_ *fisk.ParseContext) error {
 	return nil
 }
 
-func (c *consumerCmd) editAction(pc *fisk.ParseContext) error {
-	c.connectAndSetup(true, true)
-	var err error
+func (c *consumerCmd) interactiveEdit(cfg api.ConsumerConfig) (*api.ConsumerConfig, error) {
+	editor := os.Getenv("EDITOR")
+	if editor == "" {
+		return &api.ConsumerConfig{}, fmt.Errorf("set EDITOR environment variable to your chosen editor")
+	}
 
-	if c.selectedConsumer == nil {
-		c.selectedConsumer, err = c.mgr.LoadConsumer(c.stream, c.consumer)
-		fisk.FatalIfError(err, "could not load Consumer")
+	cj, err := decoratedYamlMarshal(cfg)
+	if err != nil {
+		return &api.ConsumerConfig{}, fmt.Errorf("could not create temporary file: %s", err)
 	}
 
-	if !c.selectedConsumer.IsDurable() {
-		return fmt.Errorf("only durable consumers can be edited")
+	tfile, err := os.CreateTemp("", "*.yaml")
+	if err != nil {
+		return &api.ConsumerConfig{}, fmt.Errorf("could not create temporary file: %s", err)
 	}
+	defer os.Remove(tfile.Name())
 
-	// lazy deep copy
-	t := c.selectedConsumer.Configuration()
-	tj, err := json.Marshal(t)
+	_, err = fmt.Fprint(tfile, string(cj))
 	if err != nil {
-		return err
+		return &api.ConsumerConfig{}, fmt.Errorf("could not create temporary file: %s", err)
 	}
-	var ncfg *api.ConsumerConfig
+
+	tfile.Close()
+
+	cmd := exec.Command(editor, tfile.Name())
+	cmd.Stdin = os.Stdin
+	cmd.Stdout = os.Stdout
+	cmd.Stderr = os.Stderr
+
+	err = cmd.Run()
+	if err != nil {
+		return &api.ConsumerConfig{}, fmt.Errorf("could not create temporary file: %s", err)
+	}
+
+	nb, err := os.ReadFile(tfile.Name())
+	if err != nil {
+		return &api.ConsumerConfig{}, err
+	}
+
+	ncfg := api.ConsumerConfig{}
+	err = yaml.Unmarshal(nb, &ncfg)
+	if err != nil {
+		return &api.ConsumerConfig{}, err
+	}
+
+	// some yaml quirks
+	if len(ncfg.BackOff) == 0 {
+		ncfg.BackOff = nil
+	}
+
+	return &ncfg, nil
+}
+
+func (c *consumerCmd) copyAndEditConsumer(cfg api.ConsumerConfig) (*api.ConsumerConfig, error) {
+	var err error
 
 	if c.inputFile != "" {
-		ncfg, err = c.loadConfigFile(c.inputFile)
-		if err != nil {
-			return err
-		}
-	} else {
-		err = json.Unmarshal(tj, &ncfg)
-		if err != nil {
-			return err
-		}
+		return c.loadConfigFile(c.inputFile)
+	}
 
-		if c.description != "" {
-			ncfg.Description = c.description
-		}
+	if c.description != "" {
+		cfg.Description = c.description
+	}
 
-		if c.inactiveThreshold != 0 {
-			ncfg.InactiveThreshold = c.inactiveThreshold
-		}
+	if c.inactiveThreshold != 0 {
+		cfg.InactiveThreshold = c.inactiveThreshold
+	}
 
-		if c.maxDeliver != 0 {
-			ncfg.MaxDeliver = c.maxDeliver
-		}
+	if c.maxDeliver != 0 {
+		cfg.MaxDeliver = c.maxDeliver
+	}
 
-		if c.maxAckPending != -1 {
-			ncfg.MaxAckPending = c.maxAckPending
-		}
+	if c.maxAckPending != -1 {
+		cfg.MaxAckPending = c.maxAckPending
+	}
 
-		if c.ackWait != -1*time.Second {
-			ncfg.AckWait = c.ackWait
-		}
+	if c.ackWait != -1*time.Second {
+		cfg.AckWait = c.ackWait
+	}
 
-		if c.maxWaiting != 0 {
-			ncfg.MaxWaiting = c.maxWaiting
-		}
+	if c.maxWaiting != 0 {
+		cfg.MaxWaiting = c.maxWaiting
+	}
 
-		if c.samplePct != -1 {
-			ncfg.SampleFrequency = c.sampleFreqFromInt(c.samplePct)
-		}
+	if c.samplePct != -1 {
+		cfg.SampleFrequency = c.sampleFreqFromInt(c.samplePct)
+	}
 
-		if c.maxPullBatch > 0 {
-			ncfg.MaxRequestBatch = c.maxPullBatch
-		}
+	if c.maxPullBatch > 0 {
+		cfg.MaxRequestBatch = c.maxPullBatch
+	}
 
-		if c.maxPullExpire > 0 {
-			ncfg.MaxRequestExpires = c.maxPullExpire
-		}
+	if c.maxPullExpire > 0 {
+		cfg.MaxRequestExpires = c.maxPullExpire
+	}
 
-		if c.maxPullBytes > 0 {
-			ncfg.MaxRequestMaxBytes = c.maxPullBytes
-		}
+	if c.maxPullBytes > 0 {
+		cfg.MaxRequestMaxBytes = c.maxPullBytes
+	}
 
-		if c.backoffMode != "" {
-			ncfg.BackOff, err = c.backoffPolicy()
-			if err != nil {
-				return fmt.Errorf("could not determine backoff policy: %v", err)
-			}
+	if c.backoffMode != "" {
+		cfg.BackOff, err = c.backoffPolicy()
+		if err != nil {
+			return &api.ConsumerConfig{}, fmt.Errorf("could not determine backoff policy: %v", err)
 		}
+	}
 
-		if c.delivery != "" {
-			ncfg.DeliverSubject = c.delivery
-		}
+	if c.delivery != "" {
+		cfg.DeliverSubject = c.delivery
+	}
 
-		if c.hdrsOnlySet {
-			ncfg.HeadersOnly = c.hdrsOnly
-		}
+	if c.hdrsOnlySet {
+		cfg.HeadersOnly = c.hdrsOnly
+	}
 
-		if len(c.filterSubjects) == 1 {
-			ncfg.FilterSubject = c.filterSubjects[0]
-			ncfg.FilterSubjects = nil
-		} else if len(c.filterSubjects) > 1 {
-			ncfg.FilterSubjects = c.filterSubjects
-			ncfg.FilterSubject = ""
-		}
+	if len(c.filterSubjects) == 1 {
+		cfg.FilterSubject = c.filterSubjects[0]
+		cfg.FilterSubjects = nil
+	} else if len(c.filterSubjects) > 1 {
+		cfg.FilterSubjects = c.filterSubjects
+		cfg.FilterSubject = ""
+	}
 
-		if c.replicas > 0 {
-			ncfg.Replicas = c.replicas
-		}
+	if c.replicas > 0 {
+		cfg.Replicas = c.replicas
+	}
 
-		if c.metadataIsSet {
-			ncfg.Metadata = c.metadata
-		}
+	if c.metadataIsSet {
+		cfg.Metadata = c.metadata
+	}
+
+	return &cfg, nil
+}
+func (c *consumerCmd) editAction(pc *fisk.ParseContext) error {
+	c.connectAndSetup(true, true)
+	var err error
+
+	if c.selectedConsumer == nil {
+		c.selectedConsumer, err = c.mgr.LoadConsumer(c.stream, c.consumer)
+		fisk.FatalIfError(err, "could not load Consumer")
+	}
+
+	if !c.selectedConsumer.IsDurable() {
+		return fmt.Errorf("only durable consumers can be edited")
+	}
+
+	// lazy deep copy
+	t := c.selectedConsumer.Configuration()
+	t.Metadata = iu.RemoveReservedMetadata(t.Metadata)
+
+	tj, err := json.Marshal(t)
+	if err != nil {
+		return err
+	}
+
+	var ncfg *api.ConsumerConfig
+	err = json.Unmarshal(tj, &ncfg)
+	if err != nil {
+		return err
+	}
+
+	if c.interactive {
+		ncfg, err = c.interactiveEdit(t)
+		fisk.FatalIfError(err, "could not create new configuration for Consumer %s", c.selectedConsumer.Name())
+	} else {
+		ncfg, err = c.copyAndEditConsumer(t)
+		fisk.FatalIfError(err, "could not create new configuration for Consumer %s", c.selectedConsumer.Name())
 	}
 
 	if len(ncfg.BackOff) > 0 && ncfg.AckWait != t.AckWait {