Local SNS

Fake Amazon Simple Notification Service (SNS) for local development. Supports:

• Create/List/Delete topics
• Subscribe/unsubscribe endpoints
• List subscriptions, list subscriptions by topic endpoints
• Get/Set subscription attribute endpoints
• Publish message
• Subscription persistence to file, including subscription attributes
• Subscription filtering (currently under development with some alpha features)
• Integrations with SQS, File, HTTP, RabbitMQ, Slack, and Lambda

Usage

Docker

Based on the amazoncorretto:11.0.21-alpine image. Run it with the command:

docker run -d -p 9911:9911 jameskbride/local-sns

If you would like to keep the topic/subscription database in the current host folder:

docker run -d -p 9911:9911 -v "$PWD":/etc/sns jameskbride/local-sns

Using aws-cli

The image has aws-cli preinstalled. For example, create a topic:

docker exec <CONTAINER_ID> sh -c 'aws sns --endpoint-url http://localhost:9911 create-topic --name test1'

Jar

Download the latest release from https://github.com/jameskbride/local-sns/releases and run:

DB_PATH=/tmp/db.json java -jar local-sns.jar

Requires Java11.

Configuration

Configuration can be set via environment variables:

• DB_PATH - path to subscription database file, default: db.json
• DB_OUTPUT_PATH - path that the subscription database file will be written to when updated, default: db.json
• HTTP_INTERFACE - interface to bind to, default: 0.0.0.0
• HTTP_PORT - tcp port, default: 9911
• AWS_DEFAULT_REGION - AWS region, default: us-east-1
• AWS_ACCOUNT_ID - AWS Account ID, default: 123456789012

Supported integrations

• Amazon SQS: "aws2-sqs://queueName?accessKey=xxx&secretKey=xxx&region=us-east-1&trustAllCertificates=true&overrideEndpoint=true&uriEndpointOverride=http://host:<port>
• RabbitMQ: rabbitmq://exchangeName[?options]
• HTTP: http:hostName[:port][/resourceUri][?options]
• File: file://tmp?fileName=sns.txt
• Slack: slack:@username?token=someToken&webhookUrl=https://hooks.slack.com/services/aaa/bbb/ccc
• Lambda: aws2-lambda://functionName?accessKey=xxx&secretKey=xxx&region=us-east-1&trustAllCertificates=true&overrideEndpoint=true&uriEndpointOverride=http://host:<port>

See camel documentation for more details.

Note: Environment variables can be used to specify URIs via {{env:ENV_NAME}}.

Example: aws2-sqs://{{env:QUEUE_NAME}}?amazonSQSEndpoint={{env:SQS_ENDPOINT}}&...

Example fake SQS integration:

Tested with elasticmq.

cd example
docker-compose up

Features

Subscriptions

Supported Subscription Attributes (See SetSubscriptionAttributes)

• RawMessageDelivery - NOTE: Messages sent via a Slack endpoint are always sent raw.

• FilterPolicyScope - Both MessageBody and MessageAttributes are supported (MessageAttributes is the default behavior).

• FilterPolicy - Currently under development, supported for MessageBody and MessageAttributes with some limitations:

  Feature	Supported
  Policy Complexity Constraints	No
  Policy Constraints for MessageAttribute-based filtering	Yes (only String and Number; String.Array is not currently supported)
  Nested Constraints for payload-based filtering	No (local-sns only supports top-level attribute filtering for MessageBody filter policies)
  Exact String match	Yes
  String anything-but match	No
  String prefix match	No
  String suffix match	No
  IP Address match	No
  Exact Number match	Yes
  Numeric anything-but match	No
  Numeric Value Range match	No
  And Logic	Yes
  Or Logic	Yes
  Or Operator	No
  Key Matching	No

Development

This project uses Kotlin, Vert.X, and Apache Camel for message routing.

Be sure to read the SNS documentation. The API docs in particular are useful.

It's also useful to run the equivalent aws sns CLI command with the --debug flag to better understand what the request and response payloads look like.

You can also execute an aws sns <command> --endpoint-url <local-sns url> command to point the AWS CLI to the local-sns instance.

Unit and Integration tests

./gradlew test

This command will run the unit and integration tests all together. The integration tests will create in-memory web servers that run on ports 9922 and 9933, as well as starting elasticmq on port 9234.

Thanks

Big thanks to Sergey Novikov (@s12v) for all the awesome work he did on https://github.com/s12v/sns. This project was largely inspired by Sergey's work, and takes a lot of design ideas from the original sns project.