telegraf/plugins/inputs/eventhub_consumer/eventhub_consumer.go

423 lines
13 KiB
Go

package eventhub
import (
"context"
"fmt"
"sync"
"time"
eventhub "github.com/Azure/azure-event-hubs-go/v3"
"github.com/Azure/azure-event-hubs-go/v3/persist"
"github.com/influxdata/telegraf"
"github.com/influxdata/telegraf/internal"
"github.com/influxdata/telegraf/plugins/inputs"
"github.com/influxdata/telegraf/plugins/parsers"
)
const (
defaultMaxUndeliveredMessages = 1000
)
type empty struct{}
type semaphore chan empty
// EventHub is the top level struct for this plugin
type EventHub struct {
// Configuration
ConnectionString string `toml:"connection_string"`
PersistenceDir string `toml:"persistence_dir"`
ConsumerGroup string `toml:"consumer_group"`
FromTimestamp time.Time `toml:"from_timestamp"`
Latest bool `toml:"latest"`
PrefetchCount uint32 `toml:"prefetch_count"`
Epoch int64 `toml:"epoch"`
UserAgent string `toml:"user_agent"`
PartitionIDs []string `toml:"partition_ids"`
MaxUndeliveredMessages int `toml:"max_undelivered_messages"`
EnqueuedTimeAsTs bool `toml:"enqueued_time_as_ts"`
IotHubEnqueuedTimeAsTs bool `toml:"iot_hub_enqueued_time_as_ts"`
// Metadata
ApplicationPropertyFields []string `toml:"application_property_fields"`
ApplicationPropertyTags []string `toml:"application_property_tags"`
SequenceNumberField string `toml:"sequence_number_field"`
EnqueuedTimeField string `toml:"enqueued_time_field"`
OffsetField string `toml:"offset_field"`
PartitionIDTag string `toml:"partition_id_tag"`
PartitionKeyTag string `toml:"partition_key_tag"`
IoTHubDeviceConnectionIDTag string `toml:"iot_hub_device_connection_id_tag"`
IoTHubAuthGenerationIDTag string `toml:"iot_hub_auth_generation_id_tag"`
IoTHubConnectionAuthMethodTag string `toml:"iot_hub_connection_auth_method_tag"`
IoTHubConnectionModuleIDTag string `toml:"iot_hub_connection_module_id_tag"`
IoTHubEnqueuedTimeField string `toml:"iot_hub_enqueued_time_field"`
Log telegraf.Logger `toml:"-"`
// Azure
hub *eventhub.Hub
cancel context.CancelFunc
wg sync.WaitGroup
parser parsers.Parser
in chan []telegraf.Metric
}
// SampleConfig is provided here
func (*EventHub) SampleConfig() string {
return `
## The default behavior is to create a new Event Hub client from environment variables.
## This requires one of the following sets of environment variables to be set:
##
## 1) Expected Environment Variables:
## - "EVENTHUB_NAMESPACE"
## - "EVENTHUB_NAME"
## - "EVENTHUB_CONNECTION_STRING"
##
## 2) Expected Environment Variables:
## - "EVENTHUB_NAMESPACE"
## - "EVENTHUB_NAME"
## - "EVENTHUB_KEY_NAME"
## - "EVENTHUB_KEY_VALUE"
## Uncommenting the option below will create an Event Hub client based solely on the connection string.
## This can either be the associated environment variable or hard coded directly.
# connection_string = ""
## Set persistence directory to a valid folder to use a file persister instead of an in-memory persister
# persistence_dir = ""
## Change the default consumer group
# consumer_group = ""
## By default the event hub receives all messages present on the broker, alternative modes can be set below.
## The timestamp should be in https://github.com/toml-lang/toml#offset-date-time format (RFC 3339).
## The 3 options below only apply if no valid persister is read from memory or file (e.g. first run).
# from_timestamp =
# latest = true
## Set a custom prefetch count for the receiver(s)
# prefetch_count = 1000
## Add an epoch to the receiver(s)
# epoch = 0
## Change to set a custom user agent, "telegraf" is used by default
# user_agent = "telegraf"
## To consume from a specific partition, set the partition_ids option.
## An empty array will result in receiving from all partitions.
# partition_ids = ["0","1"]
## Max undelivered messages
# max_undelivered_messages = 1000
## Set either option below to true to use a system property as timestamp.
## You have the choice between EnqueuedTime and IoTHubEnqueuedTime.
## It is recommended to use this setting when the data itself has no timestamp.
# enqueued_time_as_ts = true
# iot_hub_enqueued_time_as_ts = true
## Tags or fields to create from keys present in the application property bag.
## These could for example be set by message enrichments in Azure IoT Hub.
# application_property_tags = []
# application_property_fields = []
## Tag or field name to use for metadata
## By default all metadata is disabled
# sequence_number_field = "SequenceNumber"
# enqueued_time_field = "EnqueuedTime"
# offset_field = "Offset"
# partition_id_tag = "PartitionID"
# partition_key_tag = "PartitionKey"
# iot_hub_device_connection_id_tag = "IoTHubDeviceConnectionID"
# iot_hub_auth_generation_id_tag = "IoTHubAuthGenerationID"
# iot_hub_connection_auth_method_tag = "IoTHubConnectionAuthMethod"
# iot_hub_connection_module_id_tag = "IoTHubConnectionModuleID"
# iot_hub_enqueued_time_field = "IoTHubEnqueuedTime"
## Data format to consume.
## Each data format has its own unique set of configuration options, read
## more about them here:
## https://github.com/influxdata/telegraf/blob/master/docs/DATA_FORMATS_INPUT.md
data_format = "influx"
`
}
// Description of the plugin
func (*EventHub) Description() string {
return "Azure Event Hubs service input plugin"
}
// SetParser sets the parser
func (e *EventHub) SetParser(parser parsers.Parser) {
e.parser = parser
}
// Gather function is unused
func (*EventHub) Gather(telegraf.Accumulator) error {
return nil
}
// Init the EventHub ServiceInput
func (e *EventHub) Init() (err error) {
if e.MaxUndeliveredMessages == 0 {
e.MaxUndeliveredMessages = defaultMaxUndeliveredMessages
}
// Set hub options
hubOpts := []eventhub.HubOption{}
if e.PersistenceDir != "" {
persister, err := persist.NewFilePersister(e.PersistenceDir)
if err != nil {
return err
}
hubOpts = append(hubOpts, eventhub.HubWithOffsetPersistence(persister))
}
if e.UserAgent != "" {
hubOpts = append(hubOpts, eventhub.HubWithUserAgent(e.UserAgent))
} else {
hubOpts = append(hubOpts, eventhub.HubWithUserAgent(internal.ProductToken()))
}
// Create event hub connection
if e.ConnectionString != "" {
e.hub, err = eventhub.NewHubFromConnectionString(e.ConnectionString, hubOpts...)
} else {
e.hub, err = eventhub.NewHubFromEnvironment(hubOpts...)
}
return err
}
// Start the EventHub ServiceInput
func (e *EventHub) Start(acc telegraf.Accumulator) error {
e.in = make(chan []telegraf.Metric)
var ctx context.Context
ctx, e.cancel = context.WithCancel(context.Background())
// Start tracking
e.wg.Add(1)
go func() {
defer e.wg.Done()
e.startTracking(ctx, acc)
}()
// Configure receiver options
receiveOpts, err := e.configureReceiver()
if err != nil {
return err
}
partitions := e.PartitionIDs
if len(e.PartitionIDs) == 0 {
runtimeinfo, err := e.hub.GetRuntimeInformation(ctx)
if err != nil {
return err
}
partitions = runtimeinfo.PartitionIDs
}
for _, partitionID := range partitions {
_, err = e.hub.Receive(ctx, partitionID, e.onMessage, receiveOpts...)
if err != nil {
return fmt.Errorf("creating receiver for partition %q: %v", partitionID, err)
}
}
return nil
}
func (e *EventHub) configureReceiver() ([]eventhub.ReceiveOption, error) {
receiveOpts := []eventhub.ReceiveOption{}
if e.ConsumerGroup != "" {
receiveOpts = append(receiveOpts, eventhub.ReceiveWithConsumerGroup(e.ConsumerGroup))
}
if !e.FromTimestamp.IsZero() {
receiveOpts = append(receiveOpts, eventhub.ReceiveFromTimestamp(e.FromTimestamp))
} else if e.Latest {
receiveOpts = append(receiveOpts, eventhub.ReceiveWithLatestOffset())
}
if e.PrefetchCount != 0 {
receiveOpts = append(receiveOpts, eventhub.ReceiveWithPrefetchCount(e.PrefetchCount))
}
if e.Epoch != 0 {
receiveOpts = append(receiveOpts, eventhub.ReceiveWithEpoch(e.Epoch))
}
return receiveOpts, nil
}
// OnMessage handles an Event. When this function returns without error the
// Event is immediately accepted and the offset is updated. If an error is
// returned the Event is marked for redelivery.
func (e *EventHub) onMessage(ctx context.Context, event *eventhub.Event) error {
metrics, err := e.createMetrics(event)
if err != nil {
return err
}
select {
case <-ctx.Done():
return ctx.Err()
case e.in <- metrics:
return nil
}
}
// OnDelivery returns true if a new slot has opened up in the TrackingAccumulator.
func (e *EventHub) onDelivery(
acc telegraf.TrackingAccumulator,
groups map[telegraf.TrackingID][]telegraf.Metric,
track telegraf.DeliveryInfo,
) bool {
if track.Delivered() {
delete(groups, track.ID())
return true
}
// The metric was already accepted when onMessage completed, so we can't
// fallback on redelivery from Event Hub. Add a new copy of the metric for
// reprocessing.
metrics, ok := groups[track.ID()]
delete(groups, track.ID())
if !ok {
// The metrics should always be found, this message indicates a programming error.
e.Log.Errorf("Could not find delievery: %d", track.ID())
return true
}
backup := deepCopyMetrics(metrics)
id := acc.AddTrackingMetricGroup(metrics)
groups[id] = backup
return false
}
func (e *EventHub) startTracking(ctx context.Context, ac telegraf.Accumulator) {
acc := ac.WithTracking(e.MaxUndeliveredMessages)
sem := make(semaphore, e.MaxUndeliveredMessages)
groups := make(map[telegraf.TrackingID][]telegraf.Metric, e.MaxUndeliveredMessages)
for {
select {
case <-ctx.Done():
return
case track := <-acc.Delivered():
if e.onDelivery(acc, groups, track) {
<-sem
}
case sem <- empty{}:
select {
case <-ctx.Done():
return
case track := <-acc.Delivered():
if e.onDelivery(acc, groups, track) {
<-sem
<-sem
}
case metrics := <-e.in:
backup := deepCopyMetrics(metrics)
id := acc.AddTrackingMetricGroup(metrics)
groups[id] = backup
}
}
}
}
func deepCopyMetrics(in []telegraf.Metric) []telegraf.Metric {
metrics := make([]telegraf.Metric, 0, len(in))
for _, m := range in {
metrics = append(metrics, m.Copy())
}
return metrics
}
// CreateMetrics returns the Metrics from the Event.
func (e *EventHub) createMetrics(event *eventhub.Event) ([]telegraf.Metric, error) {
metrics, err := e.parser.Parse(event.Data)
if err != nil {
return nil, err
}
for i := range metrics {
for _, field := range e.ApplicationPropertyFields {
if val, ok := event.Get(field); ok {
metrics[i].AddField(field, val)
}
}
for _, tag := range e.ApplicationPropertyTags {
if val, ok := event.Get(tag); ok {
metrics[i].AddTag(tag, fmt.Sprintf("%v", val))
}
}
if e.SequenceNumberField != "" {
metrics[i].AddField(e.SequenceNumberField, *event.SystemProperties.SequenceNumber)
}
if e.EnqueuedTimeAsTs {
metrics[i].SetTime(*event.SystemProperties.EnqueuedTime)
} else if e.EnqueuedTimeField != "" {
metrics[i].AddField(e.EnqueuedTimeField, (*event.SystemProperties.EnqueuedTime).UnixNano()/int64(time.Millisecond))
}
if e.OffsetField != "" {
metrics[i].AddField(e.OffsetField, *event.SystemProperties.Offset)
}
if event.SystemProperties.PartitionID != nil && e.PartitionIDTag != "" {
metrics[i].AddTag(e.PartitionIDTag, string(*event.SystemProperties.PartitionID))
}
if event.SystemProperties.PartitionKey != nil && e.PartitionKeyTag != "" {
metrics[i].AddTag(e.PartitionKeyTag, *event.SystemProperties.PartitionKey)
}
if event.SystemProperties.IoTHubDeviceConnectionID != nil && e.IoTHubDeviceConnectionIDTag != "" {
metrics[i].AddTag(e.IoTHubDeviceConnectionIDTag, *event.SystemProperties.IoTHubDeviceConnectionID)
}
if event.SystemProperties.IoTHubAuthGenerationID != nil && e.IoTHubAuthGenerationIDTag != "" {
metrics[i].AddTag(e.IoTHubAuthGenerationIDTag, *event.SystemProperties.IoTHubAuthGenerationID)
}
if event.SystemProperties.IoTHubConnectionAuthMethod != nil && e.IoTHubConnectionAuthMethodTag != "" {
metrics[i].AddTag(e.IoTHubConnectionAuthMethodTag, *event.SystemProperties.IoTHubConnectionAuthMethod)
}
if event.SystemProperties.IoTHubConnectionModuleID != nil && e.IoTHubConnectionModuleIDTag != "" {
metrics[i].AddTag(e.IoTHubConnectionModuleIDTag, *event.SystemProperties.IoTHubConnectionModuleID)
}
if event.SystemProperties.IoTHubEnqueuedTime != nil {
if e.IotHubEnqueuedTimeAsTs {
metrics[i].SetTime(*event.SystemProperties.IoTHubEnqueuedTime)
} else if e.IoTHubEnqueuedTimeField != "" {
metrics[i].AddField(e.IoTHubEnqueuedTimeField, (*event.SystemProperties.IoTHubEnqueuedTime).UnixNano()/int64(time.Millisecond))
}
}
}
return metrics, nil
}
// Stop the EventHub ServiceInput
func (e *EventHub) Stop() {
err := e.hub.Close(context.Background())
if err != nil {
e.Log.Errorf("Error closing Event Hub connection: %v", err)
}
e.cancel()
e.wg.Wait()
}
func init() {
inputs.Add("eventhub_consumer", func() telegraf.Input {
return &EventHub{}
})
}