AWS Simple Notification System (SNS)
Since Camel 3.1
Only producer is supported
The AWS2 SNS component allows messages to be sent to an Amazon Simple Notification Topic. The implementation of the Amazon API is provided by the AWS SDK.
Prerequisites
You must have a valid Amazon Web Services developer account, and be signed up to use Amazon SNS. More information is available at Amazon SNS.
URI Format
aws2-sns://topicNameOrArn[?options]
The topic will be created if they don’t already exist.
You can append query options to the URI in the following format:
?options=value&option2=value&…
Configuring Options
Camel components are configured on two separate levels:
-
component level
-
endpoint level
Configuring Component Options
At the component level, you set general and shared configurations that are, then, inherited by the endpoints. It is the highest configuration level.
For example, a component may have security settings, credentials for authentication, urls for network connection and so forth.
Some components only have a few options, and others may have many. Because components typically have pre-configured defaults that are commonly used, then you may often only need to configure a few options on a component; or none at all.
You can configure components using:
-
the Component DSL.
-
in a configuration file (
application.properties
,*.yaml
files, etc). -
directly in the Java code.
Configuring Endpoint Options
You usually spend more time setting up endpoints because they have many options. These options help you customize what you want the endpoint to do. The options are also categorized into whether the endpoint is used as a consumer (from), as a producer (to), or both.
Configuring endpoints is most often done directly in the endpoint URI as path and query parameters. You can also use the Endpoint DSL and DataFormat DSL as a type safe way of configuring endpoints and data formats in Java.
A good practice when configuring options is to use Property Placeholders.
Property placeholders provide a few benefits:
-
They help prevent using hardcoded urls, port numbers, sensitive information, and other settings.
-
They allow externalizing the configuration from the code.
-
They help the code to become more flexible and reusable.
The following two sections list all the options, firstly for the component followed by the endpoint.
Component Options
The AWS Simple Notification System (SNS) component supports 30 options, which are listed below.
Name | Description | Default | Type |
---|---|---|---|
Setting the auto-creation of the topic. | false | boolean | |
Component configuration. | Sns2Configuration | ||
The ID of an AWS-managed customer master key (CMK) for Amazon SNS or a custom CMK. | String | ||
Whether the producer should be started lazy (on the first message). By starting lazy you can use this to allow CamelContext and routes to startup in situations where a producer may otherwise fail during starting and cause the route to fail being started. By deferring this startup to be lazy then the startup failure can be handled during routing messages via Camel’s routing error handlers. Beware that when the first message is processed then creating and starting the producer may take a little time and prolong the total processing time of the processing. | false | boolean | |
Only for FIFO Topic. Strategy for setting the messageDeduplicationId on the message. It can be one of the following options: useExchangeId, useContentBasedDeduplication. For the useContentBasedDeduplication option, no messageDeduplicationId will be set on the message. Enum values:
| useExchangeId | String | |
Only for FIFO Topic. Strategy for setting the messageGroupId on the message. It can be one of the following options: useConstant, useExchangeId, usePropertyValue. For the usePropertyValue option, the value of property CamelAwsSnsMessageGroupId will be used. Enum values:
| String | ||
The message structure to use such as json. | String | ||
Set the need for overriding the endpoint. This option needs to be used in combination with the uriEndpointOverride option. | false | boolean | |
The policy for this topic. Is loaded by default from classpath, but you can prefix with classpath:, file:, or http: to load the resource from different systems. | String | ||
The ARN endpoint to subscribe to. | String | ||
The region in which the SNS client needs to work. When using this parameter, the configuration will expect the lowercase name of the region (for example, ap-east-1) You’ll need to use the name Region.EU_WEST_1.id(). Enum values:
| String | ||
Define if Server Side Encryption is enabled or not on the topic. | false | boolean | |
The subject which is used if the message header 'CamelAwsSnsSubject' is not present. | String | ||
Define if the subscription between SNS Topic and SQS must be done or not. | false | boolean | |
Set the overriding uri endpoint. This option needs to be used in combination with overrideEndpoint option. | String | ||
Autowired To use the AmazonSNS as the client. | SnsClient | ||
Whether autowiring is enabled. This is used for automatic autowiring options (the option must be marked as autowired) by looking up in the registry to find if there is a single instance of matching type, which then gets configured on the component. This can be used for automatic configuring JDBC data sources, JMS connection factories, AWS Clients, etc. | true | boolean | |
Used for enabling or disabling all consumer based health checks from this component. | true | boolean | |
Used for enabling or disabling all producer based health checks from this component. Notice: Camel has by default disabled all producer based health-checks. You can turn on producer checks globally by setting camel.health.producersEnabled=true. | true | boolean | |
To define a proxy host when instantiating the SNS client. | String | ||
To define a proxy port when instantiating the SNS client. | Integer | ||
To define a proxy protocol when instantiating the SNS client. Enum values:
| HTTPS | Protocol | |
Amazon AWS Access Key. | String | ||
If using a profile credentials provider, this parameter will set the profile name. | String | ||
Amazon AWS Secret Key. | String | ||
Amazon AWS Session Token used when the user needs to assume an IAM role. | String | ||
If we want to trust all certificates in case of overriding the endpoint. | false | boolean | |
Set whether the SNS client should expect to load credentials on an AWS infra instance or to expect static credentials to be passed in. | false | boolean | |
Set whether the SNS client should expect to load credentials through a profile credentials provider. | false | boolean | |
Set whether the SNS client should expect to use Session Credentials. This is useful in a situation in which the user needs to assume an IAM role for doing operations in SNS. | false | boolean |
Endpoint Options
The AWS Simple Notification System (SNS) endpoint is configured using URI syntax:
aws2-sns:topicNameOrArn
With the following path and query parameters:
Query Parameters (27 parameters)
Name | Description | Default | Type |
---|---|---|---|
Setting the auto-creation of the topic. | false | boolean | |
To use a custom HeaderFilterStrategy to map headers to/from Camel. | HeaderFilterStrategy | ||
The ID of an AWS-managed customer master key (CMK) for Amazon SNS or a custom CMK. | String | ||
Only for FIFO Topic. Strategy for setting the messageDeduplicationId on the message. It can be one of the following options: useExchangeId, useContentBasedDeduplication. For the useContentBasedDeduplication option, no messageDeduplicationId will be set on the message. Enum values:
| useExchangeId | String | |
Only for FIFO Topic. Strategy for setting the messageGroupId on the message. It can be one of the following options: useConstant, useExchangeId, usePropertyValue. For the usePropertyValue option, the value of property CamelAwsSnsMessageGroupId will be used. Enum values:
| String | ||
The message structure to use such as json. | String | ||
Set the need for overriding the endpoint. This option needs to be used in combination with the uriEndpointOverride option. | false | boolean | |
The policy for this topic. Is loaded by default from classpath, but you can prefix with classpath:, file:, or http: to load the resource from different systems. | String | ||
The ARN endpoint to subscribe to. | String | ||
The region in which the SNS client needs to work. When using this parameter, the configuration will expect the lowercase name of the region (for example, ap-east-1) You’ll need to use the name Region.EU_WEST_1.id(). Enum values:
| String | ||
Define if Server Side Encryption is enabled or not on the topic. | false | boolean | |
The subject which is used if the message header 'CamelAwsSnsSubject' is not present. | String | ||
Define if the subscription between SNS Topic and SQS must be done or not. | false | boolean | |
Set the overriding uri endpoint. This option needs to be used in combination with overrideEndpoint option. | String | ||
Whether the producer should be started lazy (on the first message). By starting lazy you can use this to allow CamelContext and routes to startup in situations where a producer may otherwise fail during starting and cause the route to fail being started. By deferring this startup to be lazy then the startup failure can be handled during routing messages via Camel’s routing error handlers. Beware that when the first message is processed then creating and starting the producer may take a little time and prolong the total processing time of the processing. | false | boolean | |
Autowired To use the AmazonSNS as the client. | SnsClient | ||
To define a proxy host when instantiating the SNS client. | String | ||
To define a proxy port when instantiating the SNS client. | Integer | ||
To define a proxy protocol when instantiating the SNS client. Enum values:
| HTTPS | Protocol | |
Amazon AWS Access Key. | String | ||
If using a profile credentials provider, this parameter will set the profile name. | String | ||
Amazon AWS Secret Key. | String | ||
Amazon AWS Session Token used when the user needs to assume an IAM role. | String | ||
If we want to trust all certificates in case of overriding the endpoint. | false | boolean | |
Set whether the SNS client should expect to load credentials on an AWS infra instance or to expect static credentials to be passed in. | false | boolean | |
Set whether the SNS client should expect to load credentials through a profile credentials provider. | false | boolean | |
Set whether the SNS client should expect to use Session Credentials. This is useful in a situation in which the user needs to assume an IAM role for doing operations in SNS. | false | boolean |
Required SNS component options
You have to provide the amazonSNSClient in the Registry or your accessKey and secretKey to access the Amazon’s SNS.
Message Headers
The AWS Simple Notification System (SNS) component supports 3 message header(s), which is/are listed below:
Name | Description | Default | Type |
---|---|---|---|
CamelAwsSnsMessageId (producer) Constant: | The Amazon SNS message ID. | String | |
Constant: | The Amazon SNS message subject. If not set, the subject from the SnsConfiguration is used. | String | |
CamelAwsSnsMessageStructure (producer) Constant: | The message structure to use such as json. | String |
Static credentials, Default Credential Provider and Profile Credentials Provider
You have the possibility of avoiding the usage of explicit static credentials by specifying the useDefaultCredentialsProvider option and set it to true.
The order of evaluation for Default Credentials Provider is the following:
-
Java system properties -
aws.accessKeyId
andaws.secretKey
. -
Environment variables -
AWS_ACCESS_KEY_ID
andAWS_SECRET_ACCESS_KEY
. -
Web Identity Token from AWS STS.
-
The shared credentials and config files.
-
Amazon ECS container credentials - loaded from the Amazon ECS if the environment variable
AWS_CONTAINER_CREDENTIALS_RELATIVE_URI
is set. -
Amazon EC2 Instance profile credentials.
You have also the possibility of using Profile Credentials Provider, by specifying the useProfileCredentialsProvider option to true and profileCredentialsName to the profile name.
Only one of static, default and profile credentials could be used at the same time.
For more information about this you can look at AWS credentials documentation
Usage
Advanced AmazonSNS configuration
If you need more control over the SnsClient
instance configuration you can create your own instance and refer to it from the URI:
from("direct:start")
.to("aws2-sns://MyTopic?amazonSNSClient=#client");
The #client
refers to a AmazonSNS
in the Registry.
Create a subscription between an AWS SNS Topic and an AWS SQS Queue
You can create a subscription of an SQS Queue to an SNS Topic in this way:
from("direct:start")
.to("aws2-sns://test-camel-sns1?amazonSNSClient=#amazonSNSClient&subscribeSNStoSQS=true&queueArn=arn:aws:sqs:eu-central-1:123456789012:test_camel");
The #amazonSNSClient
refers to a SnsClient
in the Registry. By specifying subscribeSNStoSQS
to true and a queueArn
of an existing SQS Queue, you’ll be able to subscribe your SQS Queue to your SNS Topic.
At this point, you can consume messages coming from SNS Topic through your SQS Queue
from("aws2-sqs://test-camel?amazonSQSClient=#amazonSQSClient&delay=50&maxMessagesPerPoll=5")
.to(...);
Topic Auto-creation
With the option autoCreateTopic
users are able to avoid the auto-creation of an SNS Topic in case it doesn’t exist. The default for this option is false
. If set to false, any operation on a non-existent topic in AWS won’t be successful and an error will be returned.
SNS FIFO
SNS FIFO are supported. While creating the SQS queue, you will subscribe to the SNS topic there is an important point to remember, you’ll need to make possible for the SNS Topic to send the message to the SQS Queue.
This is clear with an example.
Suppose you created an SNS FIFO Topic called Order.fifo
and an SQS Queue called QueueSub.fifo
.
In the access Policy of the QueueSub.fifo
you should submit something like this
{
"Version": "2008-10-17",
"Id": "__default_policy_ID",
"Statement": [
{
"Sid": "__owner_statement",
"Effect": "Allow",
"Principal": {
"AWS": "arn:aws:iam::780560123482:root"
},
"Action": "SQS:*",
"Resource": "arn:aws:sqs:eu-west-1:780560123482:QueueSub.fifo"
},
{
"Effect": "Allow",
"Principal": {
"Service": "sns.amazonaws.com"
},
"Action": "SQS:SendMessage",
"Resource": "arn:aws:sqs:eu-west-1:780560123482:QueueSub.fifo",
"Condition": {
"ArnLike": {
"aws:SourceArn": "arn:aws:sns:eu-west-1:780410022472:Order.fifo"
}
}
}
]
}
This is a critical step to make the subscription work correctly.
SNS Fifo Topic Message group ID Strategy and message Deduplication ID Strategy
When sending something to the FIFO topic, you’ll need to always set up a message group ID strategy.
If the content-based message deduplication has been enabled on the SNS Fifo topic, where won’t be the need of setting a message deduplication id strategy, otherwise you’ll have to set it.
Dependencies
Maven users will need to add the following dependency to their pom.xml.
pom.xml
<dependency>
<groupId>org.apache.camel</groupId>
<artifactId>camel-aws2-sns</artifactId>
<version>${camel-version}</version>
</dependency>
where ${camel-version}
must be replaced by the actual version of Camel.
Spring Boot Auto-Configuration
When using aws2-sns with Spring Boot make sure to use the following Maven dependency to have support for auto configuration:
<dependency>
<groupId>org.apache.camel.springboot</groupId>
<artifactId>camel-aws2-sns-starter</artifactId>
<version>x.x.x</version>
<!-- use the same version as your Camel core version -->
</dependency>
The component supports 31 options, which are listed below.
Name | Description | Default | Type |
---|---|---|---|
Amazon AWS Access Key. | String | ||
To use the AmazonSNS as the client. The option is a software.amazon.awssdk.services.sns.SnsClient type. | SnsClient | ||
Setting the auto-creation of the topic. | false | Boolean | |
Whether autowiring is enabled. This is used for automatic autowiring options (the option must be marked as autowired) by looking up in the registry to find if there is a single instance of matching type, which then gets configured on the component. This can be used for automatic configuring JDBC data sources, JMS connection factories, AWS Clients, etc. | true | Boolean | |
Component configuration. The option is a org.apache.camel.component.aws2.sns.Sns2Configuration type. | Sns2Configuration | ||
Whether to enable auto configuration of the aws2-sns component. This is enabled by default. | Boolean | ||
Used for enabling or disabling all consumer based health checks from this component. | true | Boolean | |
Used for enabling or disabling all producer based health checks from this component. Notice: Camel has by default disabled all producer based health-checks. You can turn on producer checks globally by setting camel.health.producersEnabled=true. | true | Boolean | |
The ID of an AWS-managed customer master key (CMK) for Amazon SNS or a custom CMK. | String | ||
Whether the producer should be started lazy (on the first message). By starting lazy you can use this to allow CamelContext and routes to startup in situations where a producer may otherwise fail during starting and cause the route to fail being started. By deferring this startup to be lazy then the startup failure can be handled during routing messages via Camel’s routing error handlers. Beware that when the first message is processed then creating and starting the producer may take a little time and prolong the total processing time of the processing. | false | Boolean | |
Only for FIFO Topic. Strategy for setting the messageDeduplicationId on the message. It can be one of the following options: useExchangeId, useContentBasedDeduplication. For the useContentBasedDeduplication option, no messageDeduplicationId will be set on the message. | useExchangeId | String | |
Only for FIFO Topic. Strategy for setting the messageGroupId on the message. It can be one of the following options: useConstant, useExchangeId, usePropertyValue. For the usePropertyValue option, the value of property CamelAwsSnsMessageGroupId will be used. | String | ||
The message structure to use such as json. | String | ||
Set the need for overriding the endpoint. This option needs to be used in combination with the uriEndpointOverride option. | false | Boolean | |
The policy for this topic. Is loaded by default from classpath, but you can prefix with classpath:, file:, or http: to load the resource from different systems. | String | ||
If using a profile credentials provider, this parameter will set the profile name. | String | ||
To define a proxy host when instantiating the SNS client. | String | ||
To define a proxy port when instantiating the SNS client. | Integer | ||
To define a proxy protocol when instantiating the SNS client. | https | Protocol | |
The ARN endpoint to subscribe to. | String | ||
The region in which the SNS client needs to work. When using this parameter, the configuration will expect the lowercase name of the region (for example, ap-east-1) You’ll need to use the name Region.EU_WEST_1.id(). | String | ||
Amazon AWS Secret Key. | String | ||
Define if Server Side Encryption is enabled or not on the topic. | false | Boolean | |
Amazon AWS Session Token used when the user needs to assume an IAM role. | String | ||
The subject which is used if the message header 'CamelAwsSnsSubject' is not present. | String | ||
Define if the subscription between SNS Topic and SQS must be done or not. | false | Boolean | |
If we want to trust all certificates in case of overriding the endpoint. | false | Boolean | |
Set the overriding uri endpoint. This option needs to be used in combination with overrideEndpoint option. | String | ||
Set whether the SNS client should expect to load credentials on an AWS infra instance or to expect static credentials to be passed in. | false | Boolean | |
Set whether the SNS client should expect to load credentials through a profile credentials provider. | false | Boolean | |
Set whether the SNS client should expect to use Session Credentials. This is useful in a situation in which the user needs to assume an IAM role for doing operations in SNS. | false | Boolean |