KubeMQ Go SDK

The KubeMQ SDK for Go enables Go developers to seamlessly communicate with the KubeMQ server, implementing various communication patterns such as Events, EventStore, Commands, Queries, and Queues.

Table of Contents

• KubeMQ Go SDK
  • Table of Contents
  • Prerequisites
  • Installation
  • Running Examples
  • SDK Overview
  • PubSub Events Operations
  • Create Channel
    • Request Parameters
    • Response
    • Example
  • Delete Channel
    • Request Parameters
    • Response
    • Example
  • List Channels
    • Request Parameters
    • Response
    • Example
  • Send Event / Subscribe Message
    • Send Request: Event
    • Send Response
    • Subscribe Request: EventsSubscription
    • Example
  • PubSub EventsStore Operations
  • Create Channel
    • Request Parameters
    • Response
    • Example
  • Delete Channel
    • Request Parameters
    • Response
    • Example
  • List Channels
    • Request Parameters
    • Response
    • Example
  • Send Event / Subscribe Message
    • Send Request: Event
    • Send Response
    • Subscribe Request: EventsStoreSubscription
    • EventsStoreType Options
    • Example
  • Commands & Queries – Commands Operations
  • Create Channel
    • Request Parameters
    • Response
    • Example
  • Delete Channel
    • Request Parameters
    • Response
    • Example
  • List Channels
    • Request Parameters
    • Response
    • Example
  • Send Command / Receive Request
    • Send Request: CommandMessage
    • Send Response: CommandResponseMessage
    • Receive Request: CommandsSubscription
    • Example
  • Commands & Queries – Queries Operations
  • Create Channel
    • Request Parameters
    • Response
    • Example
  • Delete Channel
    • Request Parameters
    • Response
    • Example
  • List Channels
    • Request Parameters
    • Response
    • Example
  • Send Query / Receive Request
    • Send Request: QueryMessage
    • Send Response: QueryResponse
    • Receive Request: QuerySubscription
    • Example
  • Queues Operations
  • Create Channel
    • Request Parameters
    • Response
    • Example
  • Delete Channel
    • Request Parameters
    • Response
    • Example
  • List Channels
    • Request Parameters
    • Response
    • Example
  • Send / Receive Queue Messages
    • Send Request: QueueMessage
    • Send Response: SendResult
    • Receive Request: PollRequest
    • Response: PollResponse
    • Response: QueueMessage
    • Example
    • Example with Visibility

Prerequisites

• Go SDK 1.17 higher
• KubeMQ server running locally or accessible over the network

Installation

go get github.com/kubemq-io/kubemq-go

Running Examples

The examples are standalone projects that showcase the usage of the SDK. To run the examples, ensure you have a running instance of KubeMQ.

SDK Overview

The SDK implements all communication patterns available through the KubeMQ server:

• PubSub
  • Events
  • EventStore
• Commands & Queries (CQ)
  • Commands
  • Queries
• Queues

PubSub Events Operations

Create Channel

Create a new Events channel.

Request Parameters

Name	Type	Description	Default Value	Mandatory
Ctx	context	The context for the request.	None	Yes
ChannelName	String	Name of the channel you want to create	None	Yes

Response

Name	Type	Description
Err	error	Error message if any

Example

package main

import (
    "context"
    "github.com/kubemq-io/kubemq-go"
    "log"
)

func createEventsChannel() {
    ctx, cancel := context.WithCancel(context.Background())
    defer cancel()
    eventsClient, err := kubemq.NewEventsClient(ctx,
        kubemq.WithAddress("localhost", 50000),
        kubemq.WithClientId("events-channel-creator"))

    if err != nil {
        log.Fatal(err)
    }
    defer func() {
        err := eventsClient.Close()
        if err != nil {
            log.Fatal(err)
        }
    }()
    if err := eventsClient.Create(ctx, "events-channel"); err != nil {
        log.Fatal(err)
    }
}

Delete Channel

Delete an existing Events channel.

Request Parameters

Name	Type	Description	Default Value	Mandatory
ChannelName	String	Name of the channel you want to delete	None	Yes

Response

Name	Type	Description
Err	error	Error message if any

Example

package main

import (
    "context"
    "github.com/kubemq-io/kubemq-go"
    "log"
)

func deleteEventsChannel() {
    ctx, cancel := context.WithCancel(context.Background())
    defer cancel()
    eventsClient, err := kubemq.NewEventsClient(ctx,
        kubemq.WithAddress("localhost", 50000),
        kubemq.WithClientId("events-channel-delete"))

    if err != nil {
        log.Fatal(err)
    }
    defer func() {
        err := eventsClient.Close()
        if err != nil {
            log.Fatal(err)
        }
    }()
    if err := eventsClient.Delete(ctx, "events-channel"); err != nil {
        log.Fatal(err)
    }
}

List Channels

Retrieve a list of Events channels.

Request Parameters

Name	Type	Description	Default Value	Mandatory
SearchQuery	String	Search query to filter channels (optional)	None	No

Response

Returns a list where each PubSubChannel has the following attributes:

Name	Type	Description
Name	String	The name of the Pub/Sub channel.
Type	String	The type of the Pub/Sub channel.
LastActivity	long	The timestamp of the last activity on the channel, represented in milliseconds since epoch.
IsActive	boolean	Indicates whether the channel is active or not.
Incoming	PubSubStats	The statistics related to incoming messages for this channel.
Outgoing	PubSubStats	The statistics related to outgoing messages for this channel.

Example

package main

import (
    "context"
    "github.com/kubemq-io/kubemq-go"
    "log"
)

func listEventsChannels() {
    ctx, cancel := context.WithCancel(context.Background())
    defer cancel()
    eventsClient, err := kubemq.NewEventsClient(ctx,
        kubemq.WithAddress("localhost", 50000),
        kubemq.WithClientId("events-channel-lister"))

    if err != nil {
        log.Fatal(err)
    }
    defer func() {
        err := eventsClient.Close()
        if err != nil {
            log.Fatal(err)
        }
    }()
    channels, err := eventsClient.List(ctx, "")
    if err != nil {
        log.Fatal(err)
    }
    for _, channel := range channels {
        log.Println(channel)
    }
}

Send Event / Subscribe Message

Sends a message to an Events channel.

Send Request: Event

Name	Type	Description	Default Value	Mandatory
Id	String	Unique identifier for the event message.	None	No
Channel	String	The channel to which the event message is sent.	None	Yes
Metadata	String	Metadata associated with the event message.	None	No
Body	byte[]	Body of the event message in bytes.	Empty byte array	No
Tags	Map<String, String>	Tags associated with the event message as key-value pairs.	Empty Map	No

Send Response

Name	Type	Description
Err	error	Error message if any

Subscribe Request: EventsSubscription

Name	Type	Description	Default Value	Mandatory
Channel	String	The channel to subscribe to.	None	Yes
Group	String	The group to subscribe with.	None	No

Example

package main

import (
    "context"
    "github.com/kubemq-io/kubemq-go"
    "log"
    "time"
)

func sendSubscribeEvents() {
    ctx, cancel := context.WithCancel(context.Background())
    defer cancel()
    eventsClient, err := kubemq.NewEventsClient(ctx,
        kubemq.WithAddress("localhost", 50000),
        kubemq.WithClientId("events-send-subscribe"))

    if err != nil {
        log.Fatal(err)
    }
    defer func() {
        err := eventsClient.Close()
        if err != nil {
            log.Fatal(err)
        }
    }()
    subReq := &kubemq.EventsSubscription{
        Channel:  "events-channel",
        Group:    "",
        ClientId: "",
    }
    err = eventsClient.Subscribe(ctx, subReq, func(msg *kubemq.Event, err error) {
        log.Println(msg.String())
    })
    if err != nil {
        log.Fatal(err)
    }
    time.Sleep(300 * time.Second)

    err = eventsClient.Send(ctx, &kubemq.Event{
        Channel:  "events-channel",
        Metadata: "some-metadata",
        Body:     []byte("hello kubemq - sending event"),
    })

    if err != nil {
        log.Fatal(err)
    }
    time.Sleep(1 * time.Second)
}

PubSub EventsStore Operations

Create Channel

Create a new Events Store channel.

Request Parameters

Name	Type	Description	Default Value	Mandatory
Ctx	context	The context for the request.	None	Yes
ChannelName	String	Name of the channel you want to create	None	Yes

Response

Name	Type	Description
Err	error	Error message if any

Example

package main

import (
    "context"
    "github.com/kubemq-io/kubemq-go"
    "log"
)
func createEventsStoreChannel() {
    ctx, cancel := context.WithCancel(context.Background())
    defer cancel()
    eventsStoreClient, err := kubemq.NewEventsStoreClient(ctx,
        kubemq.WithAddress("localhost", 50000),
        kubemq.WithClientId("events-store-channel-creator"))
    if err != nil {
        log.Fatal(err)
    }
    defer func() {
        err := eventsStoreClient.Close()
        if err != nil {
            log.Fatal(err)
        }
    }()
    if err := eventsStoreClient.Create(ctx, "events-store-channel"); err != nil {
        log.Fatal(err)
    }
}

Delete Channel

Delete an existing Events Store channel.

Request Parameters

Name	Type	Description	Default Value	Mandatory
ChannelName	String	Name of the channel you want to delete	None	Yes

Response

Name	Type	Description
Err	error	Error message if any

Example

package main

import (
    "context"
    "github.com/kubemq-io/kubemq-go"
    "log"
)

func deleteEventsStoreChannel() {
    ctx, cancel := context.WithCancel(context.Background())
    defer cancel()
    eventsStoreClient, err := kubemq.NewEventsStoreClient(ctx,
        kubemq.WithAddress("localhost", 50000),
        kubemq.WithClientId("events-store-channel-delete"))
    if err != nil {
        log.Fatal(err)
    }
    defer func() {
        err := eventsStoreClient.Close()
        if err != nil {
            log.Fatal(err)
        }
    }()
    if err := eventsStoreClient.Delete(ctx, "events-store-channel"); err != nil {
        log.Fatal(err)
    }
}

List Channels

Retrieve a list of Events channels.

Request Parameters

Name	Type	Description	Default Value	Mandatory
SearchQuery	String	Search query to filter channels (optional)	None	No

Response

Returns a list where each PubSubChannel has the following attributes:

Name	Type	Description
Name	String	The name of the Pub/Sub channel.
Type	String	The type of the Pub/Sub channel.
LastActivity	long	The timestamp of the last activity on the channel, represented in milliseconds since epoch.
IsActive	boolean	Indicates whether the channel is active or not.
Incoming	PubSubStats	The statistics related to incoming messages for this channel.
Outgoing	PubSubStats	The statistics related to outgoing messages for this channel.

Example

package main

import (
    "context"
    "github.com/kubemq-io/kubemq-go"
    "log"
)

func listEventsStoreChannel() {
    ctx, cancel := context.WithCancel(context.Background())
    defer cancel()
    eventsStoreClient, err := kubemq.NewEventsStoreClient(ctx,
        kubemq.WithAddress("localhost", 50000),
        kubemq.WithClientId("events-store-channel-lister"))
    if err != nil {
        log.Fatal(err)
    }
    defer func() {
        err := eventsStoreClient.Close()
        if err != nil {
            log.Fatal(err)
        }
    }()
    channels, err := eventsStoreClient.List(ctx, "")
    if err != nil {
        log.Fatal(err)
    }
    for _, channel := range channels {
        log.Println(channel)
    }
}

Send Event / Subscribe Message

Sends a message to an Events channel.

Send Request: Event

Name	Type	Description	Default Value	Mandatory
Id	String	Unique identifier for the event message.	None	No
Channel	String	The channel to which the event message is sent.	None	Yes
Metadata	String	Metadata associated with the event message.	None	No
Body	byte[]	Body of the event message in bytes.	Empty byte array	No
Tags	Map<String, String>	Tags associated with the event message as key-value pairs.	Empty Map	No

Send Response

Name	Type	Description
Err	error	Error message if any

Subscribe Request: EventsStoreSubscription

Name	Type	Description	Default Value	Mandatory
Channel	String	The channel to subscribe to.	None	Yes
Group	String	The group to subscribe with.	None	No
SubscriptionType	EventsStoreSubscription	The Subscription	None	Yes

EventsStoreType Options

Type	Value	Description
StartNewOnly	1	Start storing events from the point when the subscription is made
StartFromFirst	2	Start storing events from the first event available
StartFromLast	3	Start storing events from the last event available
StartAtSequence	4	Start storing events from a specific sequence number
StartAtTime	5	Start storing events from a specific point in time
StartAtTimeDelta	6	Start storing events from a specific time delta in seconds

Example

package main

import (
    "context"
    "github.com/kubemq-io/kubemq-go"
    "log"
    "time"
)

func sendSubscribeEventsStore() {
    ctx, cancel := context.WithCancel(context.Background())
    defer cancel()
    eventsStoreClient, err := kubemq.NewEventsStoreClient(ctx,
        kubemq.WithAddress("localhost", 50000),
        kubemq.WithClientId("events-store-send-subscribe"))

    if err != nil {
        log.Fatal(err)
    }
    defer func() {
        err := eventsStoreClient.Close()
        if err != nil {
            log.Fatal(err)
        }
    }()
    subReq := &kubemq.EventsStoreSubscription{
        Channel:          "events-store-channel",
        Group:            "",
        ClientId:         "",
        SubscriptionType: kubemq.StartFromFirstEvent(),
    }
    err = eventsStoreClient.Subscribe(ctx, subReq, func(msg *kubemq.EventStoreReceive, err error) {
        log.Println(msg.String())
    })
    if err != nil {
        log.Fatal(err)
    }
    time.Sleep(1 * time.Second)

    result, err := eventsStoreClient.Send(ctx, &kubemq.EventStore{
        Channel:  "events-store-channel",
        Metadata: "some-metadata",
        Body:     []byte("hello kubemq - sending event store"),
    })
    if err != nil {
        log.Fatal(err)
    }
    log.Println(result)
    time.Sleep(1 * time.Second)

}

Commands & Queries – Commands Operations

Create Channel

Create a new Command channel.

Request Parameters

Name	Type	Description	Default Value	Mandatory
Ctx	context	The context for the request.	None	Yes
ChannelName	String	Name of the channel you want to create	None	Yes

Response

Name	Type	Description
Err	error	Error message if any

Example

package main

import (
    "context"
    "github.com/kubemq-io/kubemq-go"
    "log"
)

func createCommandsChannel() {
    ctx, cancel := context.WithCancel(context.Background())
    defer cancel()
    commandsClient, err := kubemq.NewCommandsClient(ctx,
        kubemq.WithAddress("localhost", 50000),
        kubemq.WithClientId("example"))
    if err != nil {
        log.Fatal(err)
    }
    defer func() {
        err := commandsClient.Close()
        if err != nil {
            log.Fatal(err)
        }
    }()
    if err := commandsClient.Create(ctx, "commands.A"); err != nil {
        log.Fatal(err)
    }
}

Delete Channel

Delete an existing Command channel.

Request Parameters

Name	Type	Description	Default Value	Mandatory
ChannelName	String	Name of the channel you want to delete	None	Yes

Response

Name	Type	Description
Err	error	Error message if any

Example

package main

import (
    "context"
    "github.com/kubemq-io/kubemq-go"
    "log"
)

func deleteCommandsChannel() {
    ctx, cancel := context.WithCancel(context.Background())
    defer cancel()
    commandsClient, err := kubemq.NewCommandsClient(ctx,
        kubemq.WithAddress("localhost", 50000),
        kubemq.WithClientId("example"))
    if err != nil {
        log.Fatal(err)
    }
    defer func() {
        err := commandsClient.Close()
        if err != nil {
            log.Fatal(err)
        }
    }()
    if err := commandsClient.Delete(ctx, "commands.A"); err != nil {
        log.Fatal(err)
    }
}

List Channels

Retrieve a list of Command channels.

Request Parameters

Name	Type	Description	Default Value	Mandatory
SearchQuery	String	Search query to filter channels (optional)	None	No

Response

Returns a list where each CQChannel has the following attributes:

Name	Type	Description
Name	String	The name of the Pub/Sub channel.
Type	String	The type of the Pub/Sub channel.
LastActivity	long	The timestamp of the last activity on the channel, represented in milliseconds since epoch.
IsActive	boolean	Indicates whether the channel is active or not.
Incoming	PubSubStats	The statistics related to incoming messages for this channel.
Outgoing	PubSubStats	The statistics related to outgoing messages for this channel.

Example

package main

import (
    "context"
    "github.com/kubemq-io/kubemq-go"
    "log"
)

func listCommandsChannels() {
    ctx, cancel := context.WithCancel(context.Background())
    defer cancel()
    commandsClient, err := kubemq.NewCommandsClient(ctx,
        kubemq.WithAddress("localhost", 50000),
        kubemq.WithClientId("example"))
    if err != nil {
        log.Fatal(err)
    }
    defer func() {
        err := commandsClient.Close()
        if err != nil {
            log.Fatal(err)
        }
    }()
    channels, err := commandsClient.List(ctx, "")
    if err != nil {
        log.Fatal(err)
    }
    for _, channel := range channels {
        log.Println(channel)
    }
}

Send Command / Receive Request

Sends a command request to a Command channel.

Send Request: CommandMessage

Name	Type	Description	Default Value	Mandatory
Id	String	The ID of the command message.	None	Yes
Channel	String	The channel through which the command message will be sent.	None	Yes
Metadata	String	Additional metadata associated with the command message.	None	No
Body	byte[]	The body of the command message as bytes.	Empty byte array	No
Tags	Map<String, String>	A dictionary of key-value pairs representing tags associated with the command message.	Empty Map	No
Timeout	Duration	The maximum time duration for waiting to response.	None	Yes

Send Response: CommandResponseMessage

Name	Type	Description
CommandId	String	Command Id
ResponseClientId	String	The client ID associated with the command response.
Executed	boolean	Indicates if the command has been executed.
ExecutedAt	time	The timestamp when the command response was created.
Error	String	The error message if there was an error.

Receive Request: CommandsSubscription

Name	Type	Description	Default Value	Mandatory
Channel	String	The channel for the subscription.	None	Yes
Group	String	The group associated with the subscription.	None	No

Example

package main

import (
    "context"
    "github.com/kubemq-io/kubemq-go"
    "log"
    "time"
)

func sendReceiveCommands() {
    ctx, cancel := context.WithCancel(context.Background())
    defer cancel()
    commandsClient, err := kubemq.NewCommandsClient(ctx,
        kubemq.WithAddress("localhost", 50000),
        kubemq.WithClientId("sendReceiveCommands"))

    if err != nil {
        log.Fatal(err)
    }
    defer func() {
        err := commandsClient.Close()
        if err != nil {
            log.Fatal(err)
        }
    }()
    subRequest := &kubemq.CommandsSubscription{
        Channel:  "commands",
        ClientId: "",
        Group:    "",
    }
    log.Println("subscribing to commands")
    err = commandsClient.Subscribe(ctx, subRequest, func(cmd *kubemq.CommandReceive, err error) {
        log.Println(cmd.String())
        resp := &kubemq.Response{
            RequestId:  cmd.Id,
            ResponseTo: cmd.ResponseTo,
            Metadata:   "some-metadata",
            ExecutedAt: time.Now(),
        }
        if err := commandsClient.Response(ctx, resp); err != nil {
            log.Fatal(err)
        }
    })
    if err != nil {
        log.Fatal(err)
    }
    time.Sleep(1 * time.Second)
    log.Println("sending command")
    result, err := commandsClient.Send(ctx, kubemq.NewCommand().
        SetChannel("commands").
        SetMetadata("some-metadata").
        SetBody([]byte("hello kubemq - sending command")).
        SetTimeout(time.Duration(10)*time.Second))
    if err != nil {
        log.Fatal(err)
    }
    log.Println(result)
}

Commands & Queries – Queries Operations

Create Channel

Create a new Query channel.

Request Parameters

Name	Type	Description	Default Value	Mandatory
Ctx	context	The context for the request.	None	Yes
ChannelName	String	Name of the channel you want to create	None	Yes

Response

Name	Type	Description
Err	error	Error message if any

Example

package main

import (
    "context"
    "github.com/kubemq-io/kubemq-go"
    "log"
)

func createQueriesChannel() {
    ctx, cancel := context.WithCancel(context.Background())
    defer cancel()
    queriesClient, err := kubemq.NewQueriesClient(ctx,
        kubemq.WithAddress("localhost", 50000),
        kubemq.WithClientId("example"))
    if err != nil {
        log.Fatal(err)
    }
    defer func() {
        err := queriesClient.Close()
        if err != nil {
            log.Fatal(err)
        }
    }()
    if err := queriesClient.Create(ctx, "queries.A"); err != nil {
        log.Fatal(err)
    }
}

Delete Channel

Delete an existing Query channel.

Request Parameters

Name	Type	Description	Default Value	Mandatory
ChannelName	String	Name of the channel you want to delete	None	Yes

Response

Name	Type	Description
Err	error	Error message if any

Example

package main

import (
    "context"
    "github.com/kubemq-io/kubemq-go"
    "log"
)

func deleteQueriesChannel() {
    ctx, cancel := context.WithCancel(context.Background())
    defer cancel()
    queriesClient, err := kubemq.NewQueriesClient(ctx,
        kubemq.WithAddress("localhost", 50000),
        kubemq.WithClientId("example"))
    if err != nil {
        log.Fatal(err)
    }
    defer func() {
        err := queriesClient.Close()
        if err != nil {
            log.Fatal(err)
        }
    }()
    if err := queriesClient.Delete(ctx, "queries.A"); err != nil {
        log.Fatal(err)
    }
}

List Channels

Retrieve a list of Query channels.

Request Parameters

Name	Type	Description	Default Value	Mandatory
SearchQuery	String	Search query to filter channels (optional)	None	No

Response

Returns a list where each CQChannel has the following attributes:

Name	Type	Description
Name	String	The name of the Pub/Sub channel.
Type	String	The type of the Pub/Sub channel.
LastActivity	long	The timestamp of the last activity on the channel, represented in milliseconds since epoch.
IsActive	boolean	Indicates whether the channel is active or not.
Incoming	PubSubStats	The statistics related to incoming messages for this channel.
Outgoing	PubSubStats	The statistics related to outgoing messages for this channel.

Example

package main

import (
    "context"
    "github.com/kubemq-io/kubemq-go"
    "log"
)

func listQueriesChannels() {
    ctx, cancel := context.WithCancel(context.Background())
    defer cancel()
    queriesClient, err := kubemq.NewQueriesClient(ctx,
        kubemq.WithAddress("localhost", 50000),
        kubemq.WithClientId("example"))
    if err != nil {
        log.Fatal(err)
    }
    defer func() {
        err := queriesClient.Close()
        if err != nil {
            log.Fatal(err)
        }
    }()
    channels, err := queriesClient.List(ctx, "")
    if err != nil {
        log.Fatal(err)
    }
    for _, channel := range channels {
        log.Println(channel)
    }
}

Send Query / Receive Request

Sends a query request to a Query channel.

Send Request: QueryMessage

Name	Type	Description	Default Value	Mandatory
Id	String	The ID of the query message.	None	Yes
Channel	String	The channel through which the query message will be sent.	None	Yes
Metadata	String	Additional metadata associated with the query message.	None	No
Body	byte[]	The body of the query message as bytes.	Empty byte array	No
Tags	Map<String, String>	A dictionary of key-value pairs representing tags associated with the query message.	Empty Map	No
Timeout	Duration	The maximum time duration for waiting to response.	None	Yes

Send Response: QueryResponse

Name	Type	Description
QueryId	String	Query Id
ResponseClientId	String	The client ID associated with the query response.
Executed	boolean	Indicates if the query has been executed.
Metadata	String	Additional metadata associated with the query response message.	None	No
Body	byte[]	The body of the query response message as bytes.	Empty byte array	No
Tags	Map<String, String>	A dictionary of key-value pairs representing tags associated with the query response message.	Empty Map	No
ExecutedAt	time	The timestamp when the query response was created.
Error	String	The error message if there was an error.

Receive Request: QuerySubscription

Name	Type	Description	Default Value	Mandatory
Channel	String	The channel for the subscription.	None	Yes
Group	String	The group associated with the subscription.	None	No

Example

package main

import (
    "context"
    "github.com/kubemq-io/kubemq-go"
    "log"
    "time"
)

func sendReceiveQueries() {
    ctx, cancel := context.WithCancel(context.Background())
    defer cancel()
    queriesClient, err := kubemq.NewQueriesClient(ctx,
        kubemq.WithAddress("localhost", 50000),
        kubemq.WithClientId("sendReceiveQueries"))

    if err != nil {
        log.Fatal(err)
    }
    defer func() {
        err := queriesClient.Close()
        if err != nil {
            log.Fatal(err)
        }
    }()
    subRequest := &kubemq.QueriesSubscription{
        Channel:  "queries",
        ClientId: "",
        Group:    "",
    }
    log.Println("subscribing to queries")
    err = queriesClient.Subscribe(ctx, subRequest, func(query *kubemq.QueryReceive, err error) {
        log.Println(query.String())
        resp := &kubemq.Response{
            RequestId:  query.Id,
            ResponseTo: query.ResponseTo,
            Metadata:   "some-metadata",
            ExecutedAt: time.Now(),
            Body:       []byte("hello kubemq - sending query response"),
        }
        if err := queriesClient.Response(ctx, resp); err != nil {
            log.Fatal(err)
        }
    })
    if err != nil {
        log.Fatal(err)
    }
    time.Sleep(1 * time.Second)
    log.Println("sending query")
    result, err := queriesClient.Send(ctx, kubemq.NewQuery().
        SetChannel("queries").
        SetMetadata("some-metadata").
        SetBody([]byte("hello kubemq - sending query")).
        SetTimeout(time.Duration(10)*time.Second))
    if err != nil {
        log.Fatal(err)
    }
    log.Println(result)
}

Queues Operations

Create Channel

Create a new Queue channel.

Request Parameters

Name	Type	Description	Default Value	Mandatory
Ctx	context	The context for the request.	None	Yes
ChannelName	String	Name of the channel you want to create	None	Yes

Response

Name	Type	Description
Err	error	Error message if any

Example

package main

import (
    "context"
    "github.com/kubemq-io/kubemq-go/queues_stream"
    "log"
)

func main() {
    ctx, cancel := context.WithCancel(context.Background())
    defer cancel()
    queuesClient, err := queues_stream.NewQueuesStreamClient(ctx,
        queues_stream.WithAddress("localhost", 50000),
        queues_stream.WithClientId("example"))
    if err != nil {
        log.Fatal(err)
    }
    defer func() {
        err := queuesClient.Close()
        if err != nil {
            log.Fatal(err)
        }
    }()
    if err := queuesClient.Create(ctx, "queues.A"); err != nil {
        log.Fatal(err)
    }
}

Delete Channel

Delete an existing Queue channel.

Request Parameters

Name	Type	Description	Default Value	Mandatory
ChannelName	String	Name of the channel you want to delete	None	Yes

Response

Name	Type	Description
Err	error	Error message if any

Example

package main

import (
    "context"
    "github.com/kubemq-io/kubemq-go/queues_stream"
    "log"
)

func main() {
    ctx, cancel := context.WithCancel(context.Background())
    defer cancel()
    queuesClient, err := queues_stream.NewQueuesStreamClient(ctx,
        queues_stream.WithAddress("localhost", 50000),
        queues_stream.WithClientId("example"))
    if err != nil {
        log.Fatal(err)
    }
    defer func() {
        err := queuesClient.Close()
        if err != nil {
            log.Fatal(err)
        }
    }()
    if err := queuesClient.Delete(ctx, "queues.A"); err != nil {
        log.Fatal(err)
    }
}

List Channels

Retrieve a list of Queue channels.

Request Parameters

Name	Type	Description	Default Value	Mandatory
SearchQuery	String	Search query to filter channels (optional)	None	No

Response

Returns a list where each QueuesChannel has the following attributes:

Name	Type	Description
Name	String	The name of the Pub/Sub channel.
Type	String	The type of the Pub/Sub channel.
LastActivity	long	The timestamp of the last activity on the channel, represented in milliseconds since epoch.
IsActive	boolean	Indicates whether the channel is active or not.
Incoming	PubSubStats	The statistics related to incoming messages for this channel.
Outgoing	PubSubStats	The statistics related to outgoing messages for this channel.

Example

package main

import (
    "context"
    "github.com/kubemq-io/kubemq-go/queues_stream"
    "log"
)

func main() {
    ctx, cancel := context.WithCancel(context.Background())
    defer cancel()
    queuesClient, err := queues_stream.NewQueuesStreamClient(ctx,
        queues_stream.WithAddress("localhost", 50000),
        queues_stream.WithClientId("example"))
    if err != nil {
        log.Fatal(err)
    }
    defer func() {
        err := queuesClient.Close()
        if err != nil {
            log.Fatal(err)
        }
    }()
    channels, err := queuesClient.List(ctx, "")
    if err != nil {
        log.Fatal(err)
    }
    for _, channel := range channels {
        log.Println(channel)
    }
}

Send / Receive Queue Messages

Send and receive messages from a Queue channel.

Send Request: QueueMessage

Name	Type	Description	Default Value	Mandatory
Id	String	The unique identifier for the message.	None	No
Channel	String	The channel of the message.	None	Yes
Metadata	String	The metadata associated with the message.	None	No
Body	byte[]	The body of the message.	new byte[0]	No
Tags	Map<String, String>	The tags associated with the message.	new HashMap<>()	No
PolicyDelaySeconds	int	The delay in seconds before the message becomes available in the queue.	None	No
PolicyExpirationSeconds	int	The expiration time in seconds for the message.	None	No
PolicyMaxReceiveCount	int	The number of receive attempts allowed for the message before it is moved to the dead letter queue.	None	No
PolicyMaxReceiveQueue	String	The dead letter queue where the message will be moved after reaching the maximum receive attempts.	None	No

Send Response: SendResult

Name	Type	Description
Id	String	The unique identifier of the message.
SentAt	LocalDateTime	The timestamp when the message was sent.
ExpiredAt	LocalDateTime	The timestamp when the message will expire.
DelayedTo	LocalDateTime	The timestamp when the message will be delivered.
IsError	boolean	Indicates if there was an error while sending the message.
Error	String	The error message if isError is true.

Receive Request: PollRequest

Name	Type	Description	Default Value	Mandatory
Channel	String	The channel to poll messages from.	None	Yes
MaxItems	int	The maximum number of messages to poll.	1	No
WaitTimeout	int	The wait timeout in seconds for polling messages.	60	No
AutoAck	boolean	Indicates if messages should be auto-acknowledged.	false	No
VisibilitySeconds	int	Add a visibility timeout feature for messages.	0	No

Response: PollResponse

Name	Type	Description
Messages	List	The list of received queue messages.

Response: QueueMessage

Name	Type	Description
Id	String	The unique identifier for the message.
Channel	String	The channel from which the message was received.
Metadata	String	Metadata associated with the message.
Body	byte[]	The body of the message in byte array format.
ClientID	String	The ID of the client that sent the message.
Tags	Map<String, String>	Key-value pairs representing tags for the message.
Timestamp	Instant	The timestamp when the message was created.
Sequence	long	The sequence number of the message.
ReceiveCount	int	The number of times the message has been received.
ReRouted	boolean	Indicates whether the message was rerouted.
ReRoutedFromQueue	String	The name of the queue from which the message was rerouted.
ExpirationAt	Instant	The expiration time of the message, if applicable.
DelayedTo	Instant	The time the message is delayed until, if applicable.

Example

package main

import (
    "context"
    "github.com/kubemq-io/kubemq-go/queues_stream"
    "log"
    "time"
)

func sendAndReceive() {
    ctx, cancel := context.WithCancel(context.Background())
    defer cancel()
    queuesClient, err := queues_stream.NewQueuesStreamClient(ctx,
        queues_stream.WithAddress("localhost", 50000),
        queues_stream.WithClientId("example"))
    if err != nil {
        log.Fatal(err)
    }
    defer func() {
        err := queuesClient.Close()
        if err != nil {
            log.Fatal(err)
        }
    }()
    msg := queues_stream.NewQueueMessage().
        SetId("message_id").
        SetChannel("sendAndReceive").
        SetMetadata("some-metadata").
        SetBody([]byte("hello world from KubeMQ queue")).
        SetTags(map[string]string{
            "key1": "value1",
            "key2": "value2",
        }).
        SetPolicyDelaySeconds(1).
        SetPolicyExpirationSeconds(10).
        SetPolicyMaxReceiveCount(3).
        SetPolicyMaxReceiveQueue("dlq")
    result, err := queuesClient.Send(ctx, msg)
    if err != nil {
        log.Fatal(err)
    }
    log.Println(result)
    pollRequest := queues_stream.NewPollRequest().
        SetChannel("sendAndReceive").
        SetMaxItems(1).
        SetWaitTimeout(10).
        SetAutoAck(true)
    msgs, err := queuesClient.Poll(ctx, pollRequest)
    //if err != nil {
    //  log.Fatal(err)
    //}
    //AckAll - Acknowledge all messages
    //if err := msgs.AckAll(); err != nil {
    //  log.Fatal(err)
    //}

    //NackAll - Not Acknowledge all messages
    //if err := msgs.NAckAll(); err != nil {
    //  log.Fatal(err)
    //}

    // RequeueAll - Requeue all messages
    //if err := msgs.ReQueueAll("requeue-queue-channel"); err != nil {
    //  log.Fatal(err)
    //}

    for _, msg := range msgs.Messages {
        log.Println(msg.String())

        // Ack - Acknowledge message
        if err := msg.Ack(); err != nil {
            log.Fatal(err)
        }

        // Nack - Not Acknowledge message
        //if err := msg.NAck(); err != nil {
        //  log.Fatal(err)
        //}

        // Requeue - Requeue message
        //if err := msg.ReQueue("requeue-queue-channel"); err != nil {
        //  log.Fatal(err)
        //}
    }

}

Example with Visibility

package main

import (
    "context"
    "github.com/kubemq-io/kubemq-go/queues_stream"
    "log"
    "time"
)

func sendAndReceiveWithVisibilityExpiration() {
    ctx, cancel := context.WithCancel(context.Background())
    defer cancel()
    queuesClient, err := queues_stream.NewQueuesStreamClient(ctx,
        queues_stream.WithAddress("localhost", 50000),
        queues_stream.WithClientId("example"))
    if err != nil {
        log.Fatal(err)
    }
    defer func() {
        err := queuesClient.Close()
        if err != nil {
            log.Fatal(err)
        }
    }()
    msg := queues_stream.NewQueueMessage().
        SetId("message_id").
        SetChannel("sendAndReceiveWithVisibility").
        SetMetadata("some-metadata").
        SetBody([]byte("hello world from KubeMQ queue - with visibility"))

    result, err := queuesClient.Send(ctx, msg)
    if err != nil {
        log.Fatal(err)
    }
    log.Println(result)
    pollRequest := queues_stream.NewPollRequest().
        SetChannel("sendAndReceiveWithVisibility").
        SetMaxItems(1).
        SetWaitTimeout(10).
        SetVisibilitySeconds(2)
    msgs, err := queuesClient.Poll(ctx, pollRequest)
    for _, msg := range msgs.Messages {
        log.Println(msg.String())
        log.Println("Received message, waiting 3 seconds before ack")
        time.Sleep(3 * time.Second)
        if err := msg.Ack(); err != nil {
            log.Fatal(err)
        }
    }

}
func sendAndReceiveWithVisibilityExtension() {
    ctx, cancel := context.WithCancel(context.Background())
    defer cancel()
    queuesClient, err := queues_stream.NewQueuesStreamClient(ctx,
        queues_stream.WithAddress("localhost", 50000),
        queues_stream.WithClientId("example"))
    if err != nil {
        log.Fatal(err)
    }
    defer func() {
        err := queuesClient.Close()
        if err != nil {
            log.Fatal(err)
        }
    }()
    msg := queues_stream.NewQueueMessage().
        SetId("message_id").
        SetChannel("sendAndReceiveWithVisibility").
        SetMetadata("some-metadata").
        SetBody([]byte("hello world from KubeMQ queue - with visibility"))

    result, err := queuesClient.Send(ctx, msg)
    if err != nil {
        log.Fatal(err)
    }
    log.Println(result)
    pollRequest := queues_stream.NewPollRequest().
        SetChannel("sendAndReceiveWithVisibility").
        SetMaxItems(1).
        SetWaitTimeout(10).
        SetVisibilitySeconds(2)
    msgs, err := queuesClient.Poll(ctx, pollRequest)
    for _, msg := range msgs.Messages {
        log.Println(msg.String())
        log.Println("Received message, waiting 1 seconds before ack")
        time.Sleep(1 * time.Second)
        log.Println("Extending visibility for 3 seconds and waiting 2 seconds before ack")
        if err := msg.ExtendVisibility(3); err != nil {
            log.Fatal(err)
        }
        time.Sleep(2 * time.Second)
        if err := msg.Ack(); err != nil {
            log.Fatal(err)
        }
    }
}