Allow creating topic using topic description from file (rebased)

CHANGELOG.md

@@ -5,7 +5,9 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 ## [Unreleased]
+### Added
 - [#203](https://github.com/deviceinsight/kafkactl/pull/203) Add pod override fields affinity and tolerations
+- [#210](https://github.com/deviceinsight/kafkactl/pull/210) Create topic from file
 
 ## 5.2.0 - 2024-08-08
 

README.adoc

@@ -816,6 +816,42 @@ or with protoset
 kafkactl consume <topic> --key-proto-type TopicKey --value-proto-type TopicValue --protoset-file kafkamsg.protoset
 ----
 
+=== Create topics
+
+The `create topic` allows you to create one or multiple topics.
+
+Basic usage:
+[,bash]
+----
+kafkactl create topic my-topic
+----
+
+The partition count can be specified with:
+[,bash]
+----
+kafkactl create topic my-topic --partitions 32
+----
+
+The replication factor can be specified with:
+[,bash]
+----
+kafkactl create topic my-topic --replication-factor 3
+----
+
+Configs can also be provided:
+[,bash]
+----
+kafkactl create topic my-topic --config retention.ms=3600000 --config=cleanup.policy=compact
+----
+
+The topic configuration can also be taken from an existing topic using the following:
+[,bash]
+----
+kafkactl describe topic my-topic -o json > my-topic-config.json
+kafkactl create topic my-topic-clone --file my-topic-config.json
+----
+
+
 === Altering topics
 
 Using the `alter topic` command allows you to change the partition count, replication factor and topic-level

cmd/create/create-topic.go

@@ -27,6 +27,7 @@ func newCreateTopicCmd() *cobra.Command {
 	cmdCreateTopic.Flags().Int32VarP(&flags.Partitions, "partitions", "p", 1, "number of partitions")
 	cmdCreateTopic.Flags().Int16VarP(&flags.ReplicationFactor, "replication-factor", "r", -1, "replication factor")
 	cmdCreateTopic.Flags().BoolVarP(&flags.ValidateOnly, "validate-only", "v", false, "validate only")
+	cmdCreateTopic.Flags().StringVarP(&flags.File, "file", "f", "", "file with topic description")
 	cmdCreateTopic.Flags().StringArrayVarP(&flags.Configs, "config", "c", flags.Configs, "configs in format `key=value`")
 
 	return cmdCreateTopic

cmd/create/create-topic_test.go

@@ -2,6 +2,7 @@ package create_test
 
 import (
 	"fmt"
+	"os"
 	"testing"
 	"time"
 
@@ -109,6 +110,101 @@ partitions:
 	testutil.AssertEquals(t, fmt.Sprintf(expected, topicName), stdOut)
 }
 
+func TestCreateTopicWithConfigFileIntegration(t *testing.T) {
+
+	testutil.StartIntegrationTest(t)
+
+	kafkaCtl := testutil.CreateKafkaCtlCommand()
+
+	topicName := testutil.GetPrefixedName("new-topic")
+	configFile := fmt.Sprintf(`
+name: %s
+partitions:
+- id: 0
+  oldestOffset: 0
+  newestOffset: 290
+  leader: kafka:9092
+  replicas: [1]
+  inSyncReplicas: [1]
+- id: 1
+  oldestOffset: 0
+  newestOffset: 258
+  leader: kafka:9092
+  replicas: [1]
+  inSyncReplicas: [1]
+- id: 2
+  oldestOffset: 0
+  newestOffset: 290
+  leader: kafka:9092
+  replicas: [1]
+  inSyncReplicas: [1]
+configs:
+- name: cleanup.policy
+  value: compact
+- name: max.message.bytes
+  value: "10485880"
+- name: min.cleanable.dirty.ratio
+  value: "1.0E-4"
+- name: delete.retention.ms
+  value: "0"
+- name: segment.ms
+  value: "100"
+`, topicName)
+
+	tmpFile, err := os.CreateTemp("", fmt.Sprintf("%s-*.yaml", topicName))
+	if err != nil {
+		t.Fatalf("could not create temp file with topic config: %s", err)
+	}
+	defer tmpFile.Close()
+	if _, err := tmpFile.WriteString(configFile); err != nil {
+		t.Fatalf("could not write temp config file: %s", err)
+	}
+
+	if _, err := kafkaCtl.Execute("create", "topic", topicName, "-f", tmpFile.Name()); err != nil {
+		t.Fatalf("failed to execute command: %v", err)
+	}
+
+	testutil.AssertEquals(t, fmt.Sprintf("topic created: %s", topicName), kafkaCtl.GetStdOut())
+
+	describeTopic(t, kafkaCtl, topicName)
+	stdOut := testutil.WithoutBrokerReferences(kafkaCtl.GetStdOut())
+
+	expected := `
+name: %s
+partitions:
+- id: 0
+  oldestOffset: 0
+  newestOffset: 0
+  leader: any-broker
+  replicas: [any-broker-id]
+  inSyncReplicas: [any-broker-id]
+- id: 1
+  oldestOffset: 0
+  newestOffset: 0
+  leader: any-broker
+  replicas: [any-broker-id]
+  inSyncReplicas: [any-broker-id]
+- id: 2
+  oldestOffset: 0
+  newestOffset: 0
+  leader: any-broker
+  replicas: [any-broker-id]
+  inSyncReplicas: [any-broker-id]
+configs:
+- name: cleanup.policy
+  value: compact
+- name: max.message.bytes
+  value: "10485880"
+- name: min.cleanable.dirty.ratio
+  value: "1.0E-4"
+- name: delete.retention.ms
+  value: "0"
+- name: segment.ms
+  value: "100"`
+
+	testutil.AssertEquals(t, fmt.Sprintf(expected, topicName), stdOut)
+}
+
 func describeTopic(t *testing.T, kafkaCtl testutil.KafkaCtlTestCommand, topicName string) {
 	describeTopic := func(_ uint) error {
 		_, err := kafkaCtl.Execute("describe", "topic", topicName, "-o", "yaml")

internal/topic/topic-operation.go

@@ -1,7 +1,10 @@
 package topic
 
 import (
+	"encoding/json"
 	"fmt"
+	"os"
+	"path"
 	"sort"
 	"strconv"
 	"strings"
@@ -53,6 +56,7 @@ type CreateTopicFlags struct {
 	Partitions        int32
 	ReplicationFactor int16
 	ValidateOnly      bool
+	File              string
 	Configs           []string
 }
 
@@ -111,6 +115,49 @@ func (operation *Operation) CreateTopics(topics []string, flags CreateTopicFlags
 		topicDetails.ConfigEntries[configParts[0]] = &configParts[1]
 	}
 
+	if flags.File != "" {
+		fileContent, err := os.ReadFile(flags.File)
+		if err != nil {
+			return errors.Wrap(err, "could not read topic description file")
+		}
+
+		fileTopicConfig := Topic{}
+		ext := path.Ext(flags.File)
+		var unmarshalErr error
+		switch ext {
+		case ".yml", ".yaml":
+			unmarshalErr = yaml.Unmarshal(fileContent, &fileTopicConfig)
+		case ".json":
+			unmarshalErr = json.Unmarshal(fileContent, &fileTopicConfig)
+		default:
+			return errors.Wrapf(err, "unsupported file format '%s'", ext)
+		}
+		if unmarshalErr != nil {
+			return errors.Wrap(err, "could not unmarshal config file")
+		}
+
+		numPartitions := int32(len(fileTopicConfig.Partitions))
+		if flags.Partitions == 1 {
+			topicDetails.NumPartitions = numPartitions
+		}
+
+		replicationFactors := map[int16]struct{}{}
+		for _, partition := range fileTopicConfig.Partitions {
+			replicationFactors[int16(len(partition.Replicas))] = struct{}{}
+		}
+		if flags.ReplicationFactor == -1 && len(replicationFactors) == 1 {
+			topicDetails.ReplicationFactor = int16(len(fileTopicConfig.Partitions[0].Replicas))
+		} else if flags.ReplicationFactor == -1 && len(replicationFactors) != 1 {
+			output.Warnf("replication factor from file ignored. partitions have different replicaCounts.")
+		}
+
+		for _, v := range fileTopicConfig.Configs {
+			if _, ok := topicDetails.ConfigEntries[v.Name]; !ok {
+				topicDetails.ConfigEntries[v.Name] = &v.Value
+			}
+		}
+	}
+
 	for _, topic := range topics {
 		if err = admin.CreateTopic(topic, &topicDetails, flags.ValidateOnly); err != nil {
 			return errors.Wrap(err, "failed to create topic")