Serverless Plugin: External SNS Events


What is it?

This is a plugin for the Serverless framework to allow you have a function that
uses an already existing, or external (to that service), SNS topic as an event
source.

By default, the Serverless SNS event
source will
create a new topic just for that function, but in many cases if you want a
function to subscribe to a topic, the topic will have already been created,
either in the same service or in a different service.

How do I use it?

Rather than defining an sns event for your function, define an externalSNS
event, where the value is a string, the name of the topic that you want to
subscribe this function to.

NOTE: at this time, it is assumed that the topic is in the same account and
region as the Lambda function itself. That can be changed in the future if
needed - feel free to open an issue, and preferably submit a pull request.

``yaml
functions:
doSomething:
name: ${self:service}-${self:provider.stage}-doSomething
handler: src/DoSomething.handler
events:
- externalSNS: 'some-topic-name'
`

By doing that, the deploy and remove commands in SLS will now subscribe and
unsubscribe your function to or from the specified topic. If you would like to
subscribe or unsubscribe the functions manually (outside of a deploy or remove
command), you can use serverless subscribeExternalSNS or
serverless unsubscribeExternalSNS.

How do I contribute?

Easy! Pull requests are welcome! Just do the following:

* Clone the code
* Install the dependencies with npm install
* Create a feature branch (e.g. git checkout -b my_new_feature)
* Make your changes and commit them with a reasonable commit message
* Make sure the code passes our standards with grunt standards
* Make sure all unit tests pass with npm test`

Our goal is 100% unit test coverage, with good and effective tests (it's
easy to hit 100% coverage with junk tests, so we differentiate). We **will not
accept pull requests for new features that do not include unit tests**. If you
are submitting a pull request to fix a bug, we may accept it without unit tests
(we will certainly write our own for that bug), but we strongly encourage you
to write a unit test exhibiting the bug, commit that, and then commit a fix in
a separate commit. This greatly increases the likelihood that we will accept
your pull request and the speed with which we can process it.

License

This software is released under the MIT license. See the license file for more details.