/
kafka.go
170 lines (155 loc) · 4.46 KB
/
kafka.go
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package testutil
import (
"context"
"encoding/json"
"fmt"
"runtime"
"strings"
"time"
"github.com/adevinta/vulcan-api/pkg/asyncapi"
"github.com/confluentinc/confluent-kafka-go/v2/kafka"
)
// KafkaTestBroker contains the address of the local broker used for tests.
const KafkaTestBroker = "localhost:29092"
// PrepareKafka creates a new empty topic in the local test Kafka server for
// each topic name present in topics maps. The name of the topics created will
// have the following shape:
// <calling_function_name>_<original_topic_name>_test. It returns a new map
// with the entities remapped to new topics created.
func PrepareKafka(topics map[string]string) (map[string]string, error) {
// Generate a unique deterministic topic name for the caller of this function.
tRef := time.Now().Unix()
newTopics := map[string]string{}
var newTopicNames []string
for entity, topic := range topics {
pc, _, _, _ := runtime.Caller(1)
callerName := strings.Replace(runtime.FuncForPC(pc).Name(), ".", "_", -1)
callerName = strings.Replace(callerName, "-", "_", -1)
parts := strings.Split(callerName, "/")
name := strings.ToLower(fmt.Sprintf("%s_%s_%d_test", topic, parts[len(parts)-1], tRef))
newTopics[entity] = name
newTopicNames = append(newTopicNames, name)
}
err := createTopics(newTopicNames)
if err != nil {
return nil, err
}
return newTopics, nil
}
func createTopics(names []string) error {
config := kafka.ConfigMap{
"bootstrap.servers": KafkaTestBroker,
}
client, err := kafka.NewAdminClient(&config)
if err != nil {
return err
}
waitDuration := time.Duration(time.Second * 60)
opTimeout := kafka.SetAdminOperationTimeout(waitDuration)
results, err := client.DeleteTopics(context.Background(), names, opTimeout)
if err != nil {
return err
}
tResults := topicsOpResult(results)
if tResults.Error() != kafka.ErrNoError && tResults.Error() != kafka.ErrUnknownTopicOrPart {
return fmt.Errorf("error deleting topic %s", tResults.Error())
}
for _, name := range names {
topic := kafka.TopicSpecification{
Topic: name,
NumPartitions: 1,
}
// Retry the create topic operation until in does not return an error
// indicating that the topic already exits, at which point we have a
// clean new topic created.
for {
results, err = client.CreateTopics(context.Background(), []kafka.TopicSpecification{topic}, opTimeout)
if err != nil {
return err
}
tResults = topicsOpResult(results)
if tResults.Error() == kafka.ErrNoError {
break
}
if tResults.Error() == kafka.ErrTopicAlreadyExists {
continue
}
return fmt.Errorf("error creating topics: %s", tResults.Error())
}
}
return nil
}
type topicsOpResult []kafka.TopicResult
func (t topicsOpResult) Error() kafka.ErrorCode {
for _, res := range t {
if res.Error.Code() != kafka.ErrNoError {
return res.Error.Code()
}
}
return kafka.ErrNoError
}
type AssetTopicData struct {
Payload asyncapi.AssetPayload
Headers map[string][]byte
}
func ReadAllAssetsTopic(topic string) ([]AssetTopicData, error) {
broker := KafkaTestBroker
config := kafka.ConfigMap{
"go.events.channel.enable": true,
"bootstrap.servers": broker,
"group.id": "test_" + topic,
"enable.partition.eof": true,
"auto.offset.reset": "earliest",
"enable.auto.commit": false,
}
c, err := kafka.NewConsumer(&config)
if err != nil {
return nil, err
}
defer c.Close()
if err = c.Subscribe(topic, nil); err != nil {
return nil, err
}
var topicAssetsData []AssetTopicData
Loop:
for ev := range c.Events() {
switch e := ev.(type) {
case *kafka.Message:
data := e.Value
asset := asyncapi.AssetPayload{}
// The data will be empty in case the event is a tombstone.
if len(data) > 0 {
err = json.Unmarshal(data, &asset)
if err != nil {
return nil, err
}
}
headers := map[string][]byte{}
for _, v := range e.Headers {
headers[v.Key] = v.Value
}
topicData := AssetTopicData{
Payload: asset,
Headers: headers,
}
topicAssetsData = append(topicAssetsData, topicData)
_, err := c.CommitOffsets([]kafka.TopicPartition{
{
Topic: e.TopicPartition.Topic,
Partition: e.TopicPartition.Partition,
Offset: e.TopicPartition.Offset + 1,
},
})
if err != nil {
return nil, err
}
case kafka.Error:
return nil, e
case kafka.PartitionEOF:
break Loop
default:
return nil, fmt.Errorf("received unexpected message %v", e)
}
}
return topicAssetsData, nil
}