Chapter 10. AWS Simple Notification System (SNS) 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 . 10.1. Dependencies When using aws2-sns with Red Hat build of Camel Spring Boot, add the following Maven dependency to your pom.xml to have support for auto configuration: <dependency> <groupId>org.apache.camel.springboot</groupId> <artifactId>camel-aws2-sns-starter</artifactId> </dependency> 10.2. URI Format The topic will be created if they don't already exists. You can append query options to the URI in the following format, 10.3. Configuring Options Camel components are configured on two separate levels: component level endpoint level 10.3.1. 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. 10.3.2. 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. 10.4. Component Options The AWS Simple Notification System (SNS) component supports 24 options, which are listed below. Name Description Default Type amazonSNSClient (producer) Autowired To use the AmazonSNS as the client. SnsClient autoCreateTopic (producer) Setting the autocreation of the topic. false boolean configuration (producer) Component configuration. Sns2Configuration kmsMasterKeyId (producer) The ID of an AWS-managed customer master key (CMK) for Amazon SNS or a custom CMK. String lazyStartProducer (producer) 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 messageDeduplicationIdStrategy (producer) Only for FIFO Topic. Strategy for setting the messageDeduplicationId on the message. Can be one of the following options: useExchangeId, useContentBasedDeduplication. For the useContentBasedDeduplication option, no messageDeduplicationId will be set on the message. Enum values: useExchangeId useContentBasedDeduplication useExchangeId String messageGroupIdStrategy (producer) Only for FIFO Topic. Strategy for setting the messageGroupId on the message. Can be one of the following options: useConstant, useExchangeId, usePropertyValue. For the usePropertyValue option, the value of property CamelAwsMessageGroupId will be used. Enum values: useConstant useExchangeId usePropertyValue String messageStructure (producer) The message structure to use such as json. String overrideEndpoint (producer) Set the need for overidding the endpoint. This option needs to be used in combination with uriEndpointOverride option. false boolean policy (producer) 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 proxyHost (producer) To define a proxy host when instantiating the SNS client. String proxyPort (producer) To define a proxy port when instantiating the SNS client. Integer proxyProtocol (producer) To define a proxy protocol when instantiating the SNS client. Enum values: HTTP HTTPS HTTPS Protocol queueUrl (producer) The queueUrl to subscribe to. String region (producer) The region in which 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 serverSideEncryptionEnabled (producer) Define if Server Side Encryption is enabled or not on the topic. false boolean subject (producer) The subject which is used if the message header 'CamelAwsSnsSubject' is not present. String subscribeSNStoSQS (producer) Define if the subscription between SNS Topic and SQS must be done or not. false boolean trustAllCertificates (producer) If we want to trust all certificates in case of overriding the endpoint. false boolean uriEndpointOverride (producer) Set the overriding uri endpoint. This option needs to be used in combination with overrideEndpoint option. String useDefaultCredentialsProvider (producer) 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 autowiredEnabled (advanced) 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 accessKey (security) Amazon AWS Access Key. String secretKey (security) Amazon AWS Secret Key. String 10.5. Endpoint Options The AWS Simple Notification System (SNS) endpoint is configured using URI syntax: with the following path and query parameters: 10.5.1. Path Parameters (1 parameters) Name Description Default Type topicNameOrArn (producer) Required Topic name or ARN. String 10.5.2. Query Parameters (23 parameters) Name Description Default Type amazonSNSClient (producer) Autowired To use the AmazonSNS as the client. SnsClient autoCreateTopic (producer) Setting the autocreation of the topic. false boolean headerFilterStrategy (producer) To use a custom HeaderFilterStrategy to map headers to/from Camel. HeaderFilterStrategy kmsMasterKeyId (producer) The ID of an AWS-managed customer master key (CMK) for Amazon SNS or a custom CMK. String lazyStartProducer (producer) 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 messageDeduplicationIdStrategy (producer) Only for FIFO Topic. Strategy for setting the messageDeduplicationId on the message. Can be one of the following options: useExchangeId, useContentBasedDeduplication. For the useContentBasedDeduplication option, no messageDeduplicationId will be set on the message. Enum values: useExchangeId useContentBasedDeduplication useExchangeId String messageGroupIdStrategy (producer) Only for FIFO Topic. Strategy for setting the messageGroupId on the message. Can be one of the following options: useConstant, useExchangeId, usePropertyValue. For the usePropertyValue option, the value of property CamelAwsMessageGroupId will be used. Enum values: useConstant useExchangeId usePropertyValue String messageStructure (producer) The message structure to use such as json. String overrideEndpoint (producer) Set the need for overidding the endpoint. This option needs to be used in combination with uriEndpointOverride option. false boolean policy (producer) 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 proxyHost (producer) To define a proxy host when instantiating the SNS client. String proxyPort (producer) To define a proxy port when instantiating the SNS client. Integer proxyProtocol (producer) To define a proxy protocol when instantiating the SNS client. Enum values: HTTP HTTPS HTTPS Protocol queueUrl (producer) The queueUrl to subscribe to. String region (producer) The region in which 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 serverSideEncryptionEnabled (producer) Define if Server Side Encryption is enabled or not on the topic. false boolean subject (producer) The subject which is used if the message header 'CamelAwsSnsSubject' is not present. String subscribeSNStoSQS (producer) Define if the subscription between SNS Topic and SQS must be done or not. false boolean trustAllCertificates (producer) If we want to trust all certificates in case of overriding the endpoint. false boolean uriEndpointOverride (producer) Set the overriding uri endpoint. This option needs to be used in combination with overrideEndpoint option. String useDefaultCredentialsProvider (producer) 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 accessKey (security) Amazon AWS Access Key. String secretKey (security) Amazon AWS Secret Key. String Required SNS component options You have to provide the amazonSNSClient in the Registry or your accessKey and secretKey to access the Amazon's SNS . 10.6. Usage 10.6.1. Static credentials vs Default Credential Provider You have the possibility of avoiding the usage of explicit static credentials, by specifying the useDefaultCredentialsProvider option and set it to true. Java system properties - aws.accessKeyId and aws.secretKey Environment variables - AWS_ACCESS_KEY_ID and AWS_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. For more information about this you can look at AWS credentials documentation . 10.6.2. Message headers evaluated by the SNS producer Header Type Description CamelAwsSnsSubject String The Amazon SNS message subject. If not set, the subject from the SnsConfiguration is used. 10.6.3. Message headers set by the SNS producer Header Type Description CamelAwsSnsMessageId String The Amazon SNS message ID. 10.6.4. 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. 10.6.5. 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&queueUrl=https://sqs.eu-central-1.amazonaws.com/780410022472/test-camel"); The #amazonSNSClient refers to a SnsClient in the Registry. By specifying subscribeSNStoSQS to true and a queueUrl 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(...); 10.7. Topic Autocreation With the option autoCreateTopic users are able to avoid the autocreation of an SNS Topic in case it doesn't exist. The default for this option is true . If set to false any operation on a not-existent topic in AWS won't be successful and an error will be returned. 10.8. 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 message to the SQS Queue. 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. 10.8.1. 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. 10.9. Examples 10.9.1. Producer Examples Sending to a topic from("direct:start") .to("aws2-sns://camel-topic?subject=The+subject+message&autoCreateTopic=true"); 10.10. 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>USD{camel-version}</version> </dependency> where {camel-version} must be replaced by the actual version of Camel. 10.11. Spring Boot Auto-Configuration The component supports 25 options, which are listed below. Name Description Default Type camel.component.aws2-sns.access-key Amazon AWS Access Key. String camel.component.aws2-sns.amazon-s-n-s-client To use the AmazonSNS as the client. The option is a software.amazon.awssdk.services.sns.SnsClient type. SnsClient camel.component.aws2-sns.auto-create-topic Setting the autocreation of the topic. false Boolean camel.component.aws2-sns.autowired-enabled 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 camel.component.aws2-sns.configuration Component configuration. The option is a org.apache.camel.component.aws2.sns.Sns2Configuration type. Sns2Configuration camel.component.aws2-sns.enabled Whether to enable auto configuration of the aws2-sns component. This is enabled by default. Boolean camel.component.aws2-sns.kms-master-key-id The ID of an AWS-managed customer master key (CMK) for Amazon SNS or a custom CMK. String camel.component.aws2-sns.lazy-start-producer 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 camel.component.aws2-sns.message-deduplication-id-strategy Only for FIFO Topic. Strategy for setting the messageDeduplicationId on the message. Can be one of the following options: useExchangeId, useContentBasedDeduplication. For the useContentBasedDeduplication option, no messageDeduplicationId will be set on the message. useExchangeId String camel.component.aws2-sns.message-group-id-strategy Only for FIFO Topic. Strategy for setting the messageGroupId on the message. Can be one of the following options: useConstant, useExchangeId, usePropertyValue. For the usePropertyValue option, the value of property CamelAwsMessageGroupId will be used. String camel.component.aws2-sns.message-structure The message structure to use such as json. String camel.component.aws2-sns.override-endpoint Set the need for overidding the endpoint. This option needs to be used in combination with uriEndpointOverride option. false Boolean camel.component.aws2-sns.policy 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 camel.component.aws2-sns.proxy-host To define a proxy host when instantiating the SNS client. String camel.component.aws2-sns.proxy-port To define a proxy port when instantiating the SNS client. Integer camel.component.aws2-sns.proxy-protocol To define a proxy protocol when instantiating the SNS client. Protocol camel.component.aws2-sns.queue-url The queueUrl to subscribe to. String camel.component.aws2-sns.region The region in which 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 camel.component.aws2-sns.secret-key Amazon AWS Secret Key. String camel.component.aws2-sns.server-side-encryption-enabled Define if Server Side Encryption is enabled or not on the topic. false Boolean camel.component.aws2-sns.subject The subject which is used if the message header 'CamelAwsSnsSubject' is not present. String camel.component.aws2-sns.subscribe-s-n-sto-s-q-s Define if the subscription between SNS Topic and SQS must be done or not. false Boolean camel.component.aws2-sns.trust-all-certificates If we want to trust all certificates in case of overriding the endpoint. false Boolean camel.component.aws2-sns.uri-endpoint-override Set the overriding uri endpoint. This option needs to be used in combination with overrideEndpoint option. String camel.component.aws2-sns.use-default-credentials-provider 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

Commands:
<dependency> <groupId>org.apache.camel.springboot</groupId> <artifactId>camel-aws2-sns-starter</artifactId> </dependency>
aws2-sns://topicNameOrArn[?options]
?options=value&option2=value&...
aws2-sns:topicNameOrArn
from("direct:start") .to("aws2-sns://MyTopic?amazonSNSClient=#client");
from("direct:start") .to("aws2-sns://test-camel-sns1?amazonSNSClient=#amazonSNSClient&subscribeSNStoSQS=true&queueUrl=https://sqs.eu-central-1.amazonaws.com/780410022472/test-camel");
from("aws2-sqs://test-camel?amazonSQSClient=#amazonSQSClient&delay=50&maxMessagesPerPoll=5") .to(...);
{ "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" } } } ] }
from("direct:start") .to("aws2-sns://camel-topic?subject=The+subject+message&autoCreateTopic=true");
<dependency> <groupId>org.apache.camel</groupId> <artifactId>camel-aws2-sns</artifactId> <version>USD{camel-version}</version> </dependency>