Slack Component

Available as of Camel version 2.16

The slack component allows you to connect to an instance of http://www.slack.com/[Slack] and delivers a message contained in the message body via a pre established https://api.slack.com/incoming-webhooks[Slack incoming webhook].

Maven users will need to add the following dependency to their pom.xml for this component:

<dependency>
    <groupId>org.apache.camel</groupId>
    <artifactId>camel-slack</artifactId>
    <version>x.x.x</version>
    <!-- use the same version as your Camel core version -->
</dependency>

URI format

To send a message to a channel.

slack:#channel[?options]

To send a direct message to a slackuser.

slack:@username[?options]

Options

The Slack component supports 2 options, which are listed below.

Name Description Default Type

webhookUrl (common)

The incoming webhook URL

String

resolveProperty Placeholders (advanced)

Whether the component should resolve property placeholders on itself when starting. Only properties which are of String type can use property placeholders.

true

boolean

The Slack endpoint is configured using URI syntax:

slack:channel

with the following path and query parameters:

Path Parameters (1 parameters):

Name Description Default Type

channel

Required The channel name (syntax #name) or slackuser (syntax userName) to send a message directly to an user.

String

Query Parameters (26 parameters):

Name Description Default Type

bridgeErrorHandler (consumer)

Allows for bridging the consumer to the Camel routing Error Handler, which mean any exceptions occurred while the consumer is trying to pickup incoming messages, or the likes, will now be processed as a message and handled by the routing Error Handler. By default the consumer will use the org.apache.camel.spi.ExceptionHandler to deal with exceptions, that will be logged at WARN or ERROR level and ignored.

false

boolean

maxResults (consumer)

The Max Result for the poll

10

String

sendEmptyMessageWhenIdle (consumer)

If the polling consumer did not poll any files, you can enable this option to send an empty message (no body) instead.

false

boolean

serverUrl (consumer)

The Server URL of the Slack instance

https://slack.com

String

token (consumer)

The token to use

String

exceptionHandler (consumer)

To let the consumer use a custom ExceptionHandler. Notice if the option bridgeErrorHandler is enabled then this option is not in use. By default the consumer will deal with exceptions, that will be logged at WARN or ERROR level and ignored.

ExceptionHandler

exchangePattern (consumer)

Sets the exchange pattern when the consumer creates an exchange.

ExchangePattern

pollStrategy (consumer)

A pluggable org.apache.camel.PollingConsumerPollingStrategy allowing you to provide your custom implementation to control error handling usually occurred during the poll operation before an Exchange have been created and being routed in Camel.

PollingConsumerPoll Strategy

iconEmoji (producer)

Use a Slack emoji as an avatar

String

iconUrl (producer)

The avatar that the component will use when sending message to a channel or user.

String

username (producer)

This is the username that the bot will have when sending messages to a channel or user.

String

webhookUrl (producer)

The incoming webhook URL

String

synchronous (advanced)

Sets whether synchronous processing should be strictly used, or Camel is allowed to use asynchronous processing (if supported).

false

boolean

backoffErrorThreshold (scheduler)

The number of subsequent error polls (failed due some error) that should happen before the backoffMultipler should kick-in.

int

backoffIdleThreshold (scheduler)

The number of subsequent idle polls that should happen before the backoffMultipler should kick-in.

int

backoffMultiplier (scheduler)

To let the scheduled polling consumer backoff if there has been a number of subsequent idles/errors in a row. The multiplier is then the number of polls that will be skipped before the next actual attempt is happening again. When this option is in use then backoffIdleThreshold and/or backoffErrorThreshold must also be configured.

int

delay (scheduler)

Milliseconds before the next poll. You can also specify time values using units, such as 60s (60 seconds), 5m30s (5 minutes and 30 seconds), and 1h (1 hour).

500

long

greedy (scheduler)

If greedy is enabled, then the ScheduledPollConsumer will run immediately again, if the previous run polled 1 or more messages.

false

boolean

initialDelay (scheduler)

Milliseconds before the first poll starts. You can also specify time values using units, such as 60s (60 seconds), 5m30s (5 minutes and 30 seconds), and 1h (1 hour).

1000

long

runLoggingLevel (scheduler)

The consumer logs a start/complete log line when it polls. This option allows you to configure the logging level for that.

TRACE

LoggingLevel

scheduledExecutorService (scheduler)

Allows for configuring a custom/shared thread pool to use for the consumer. By default each consumer has its own single threaded thread pool.

ScheduledExecutor Service

scheduler (scheduler)

To use a cron scheduler from either camel-spring or camel-quartz2 component

none

ScheduledPollConsumer Scheduler

schedulerProperties (scheduler)

To configure additional properties when using a custom scheduler or any of the Quartz2, Spring based scheduler.

Map

startScheduler (scheduler)

Whether the scheduler should be auto started.

true

boolean

timeUnit (scheduler)

Time unit for initialDelay and delay options.

MILLISECONDS

TimeUnit

useFixedDelay (scheduler)

Controls if fixed delay or fixed rate is used. See ScheduledExecutorService in JDK for details.

true

boolean

Spring Boot Auto-Configuration

When using Spring Boot make sure to use the following Maven dependency to have support for auto configuration:

<dependency>
  <groupId>org.apache.camel</groupId>
  <artifactId>camel-slack-starter</artifactId>
  <version>x.x.x</version>
  <!-- use the same version as your Camel core version -->
</dependency>

The component supports 3 options, which are listed below.

Name Description Default Type

camel.component.slack.enabled

Enable slack component

true

Boolean

camel.component.slack.resolve-property-placeholders

Whether the component should resolve property placeholders on itself when starting. Only properties which are of String type can use property placeholders.

true

Boolean

camel.component.slack.webhook-url

The incoming webhook URL

String

SlackComponent

The SlackComponent with XML must be configured as a Spring or Blueprint bean that contains the incoming webhook url for the integration as a parameter.

<bean id="slack" class="org.apache.camel.component.slack.SlackComponent">
    <property name="webhookUrl" value="https://hooks.slack.com/services/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"/>
</bean>

For Java you can configure this using Java code.

Example

A CamelContext with Blueprint could be as:

<?xml version="1.0" encoding="UTF-8"?>
<blueprint xmlns="http://www.osgi.org/xmlns/blueprint/v1.0.0" default-activation="lazy">

    <bean id="slack" class="org.apache.camel.component.slack.SlackComponent">
        <property name="webhookUrl" value="https://hooks.slack.com/services/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"/>
    </bean>

    <camelContext xmlns="http://camel.apache.org/schema/blueprint">
        <route>
            <from uri="direct:test"/>
            <to uri="slack:#channel?iconEmoji=:camel:&amp;username=CamelTest"/>
        </route>
    </camelContext>

</blueprint>

Consumer

You can use also a consumer for messages in channel

from("slack://general?token=RAW(<YOUR_TOKEN>)&maxResults=1")
    .to("mock:result");

In this way you’ll get the last message from general channel. The consumer will take track of the timestamp of the last message consumed and in the next poll it will check from that timestamp.