SNS event compiler tries to use an existing ARN as a topic name #2183

danielkoo · 2016-09-22T02:31:42Z

This is a Bug Report

Description

For bug reports:

What went wrong?
When specifying an existing SNS ARN as an event in serverless.yml, the instructions https://github.com/serverless/serverless/blob/master/docs/02-providers/aws/events/04-sns.md

says one way is to use the following format:

events:
      - sns: arn:xxx

However, I get the error "Invalid parameter: Topic Name" as Serverless thinks the ARN is a topic name and tries to create a new topic with it, instead of leaving it as an existing ARN.

What did you expect should have happened?
If event.sns is a string and is a valid SNS ARN value, it should not create a new SNS topic using the supplied ARN as the topic name; rather, it should set up the event using the existing SNS ARN.

I believe this is the part of the code in lib/plugins/aws/deploy/compile/events/sns/index.js

} else if (typeof event.sns === 'string') {
              topicName = event.sns;
}

The current workaround is just to use the other format to explicitly specify the topic ARN:

- sns:
        topicArn: arn:aws:sns:xxxx:xxxx:xxxx

What was the config you used?

events:
      - sns: arn:aws:sns:xxxx:xxxx:xxxx

What stacktrace or error message from your provider did you see?

 $ sls deploy
Serverless: Creating Stack...
Serverless: Checking Stack create progress...
.....
Serverless: Stack create finished...
Serverless: Packaging service...
Serverless: Uploading CloudFormation file to S3...
Serverless: Uploading service .zip file to S3...
Serverless: Updating Stack...
Serverless: Checking Stack update progress...
....................................................Serverless: Deployment failed!

  Serverless Error ---------------------------------------

     An error occurred while provisioning your stack: SNSTopicArnawssnsxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
     - Invalid parameter: Topic Name.

  Get Support --------------------------------------------
     Docs:          docs.serverless.com
     Bugs:          github.com/serverless/serverless/issues

Similar or dependent issues:
N/A

Additional Data

_Serverless Framework Version you're using_: 1.0.0-rc.1
_Operating System_: Debian Linux
_Stack Trace_:
Please see above
_Provider Error messages_:

     - Invalid parameter: Topic Name.

The text was updated successfully, but these errors were encountered:

johncmckim · 2016-10-05T05:44:05Z

I'd like to submit a PR of this issue if it's up for grabs.

johncmckim · 2016-10-05T06:13:07Z

@danielkoo the issue seems a bit larger than just that one line. It looks like support for an sns arn was removed in 1.0.0-rc.2. Specifically this commit

My guess on why it was removed is that Cloud Formation does not support subscribing SNS topics to events separately to creating the topic. The only thing that config could help with is to add that lambda permission.

That all said. It is possible to create a custom CF resource backed by a lambda function. See https://gist.github.com/martinssipenko/4d7b48a3d6a6751e7464 as an example.

@eahefnawy @flomotlik @pmuens what do you think of the Serverless framework supporting existing SNS topics via a custom CF resource?

eahefnawy · 2016-10-05T09:05:15Z

Hmmm I don't remember explicitly discussing removing it, might have happened by mistake due to the big change. But generally it was't doing much other than adding just another Lambda::Permission resource.

I'm definitely onboard with the suggested custom template idea! It'd make the feature more valuable . And I think it could solve other issues we might have in the framework due to CF limits.

jthomerson · 2016-10-16T22:21:27Z

@danielkoo FYI: I made a plugin that allows for "external" (or already existing) SNS topics as an event source for your Lambda function. It automatically handles subscribing and unsubscribing also. See https://github.com/silvermine/serverless-plugin-external-sns-events

alexef · 2016-10-21T09:08:41Z

@jthomerson the plugin is cool, but it only works for SNS topics within the same account. Can you extend it to a generic sns topic arn, like sls used to support?

johncmckim · 2016-10-22T01:53:55Z

@jthomerson the implementation of it might be affected by #2473 if that idea is accepted. Did you consider using a custom CloudFormation resource? How does the plugin handle rollbacks i.e. a failed deploy?

viz · 2016-11-09T23:43:50Z

Looks like the work-around described by @danielkoo no longer works. I tried adding topicArn: ... and got the following error:

  Serverless Error ---------------------------------------

     Missing "topicName" property for sns event in function
     updateStatusSubmitted The correct syntax is: sns: topic-name
     OR an object with "topicName" AND "displayName" properties.
     Please check the docs for more info.

  Get Support --------------------------------------------
     Docs:          docs.serverless.com
     Bugs:          github.com/serverless/serverless/issues

  Your Environment Information -----------------------------
     OS:                 darwin
     Node Version:       6.6.0
     Serverless Version: 1.1.0

jschr · 2016-11-10T07:21:00Z

Running into the same issue trying to use an existing topic. I've tried the following but I get the same errors as above:

- sns: arn:xxx

- sns:
        - topicArn: arn:xxx

- sns:
        - topicName: name
        - topicArn: arn:xxx

- sns:
        - topicName: name
        - displayName: displayName
        - topicArn: arn:xxx

gmetzker · 2016-12-13T01:25:54Z

Getting similar issues with several types of syntax, similar to @jschr
Would be nice to see the standard sns syntax support pre-existing topics by wiring up subscriptions. I realize CloudFormation has limitations on subscriptions but perhaps something similar to @jthomerson s plugin could be built-in.

dougmoscrop · 2016-12-20T15:37:32Z

@gmetzker #2796 fixes it as far as I know. what kind of limitations are there on CFN subscriptions?

gmetzker · 2016-12-20T16:12:10Z

@dougmoscrop: When trying to update an existing CF stack that contained SNS subscriptions, CF used to throw out errors:

Update to resource type AWS::SNS::Topic is not supported
See Stackoverflow

I can't remember the specifics but if I recall correctly it seemed that if you defined an SNS subscription in a CF stack and later wanted to make changes or do an Update Stack you might run into this error and the update was not allowed.

AWS may have fixed the limitation. It used to be documented but I can't seem to find a reference.

I would be curious if your serverless generated CF stack contains SNS subscriptions and if you could roll subsequent updates to your stack. Perhaps this works if the SNS subscription was created outside of the template...?

If this works that would be great for my use case.

dougmoscrop · 2016-12-20T16:14:29Z

I see - I think my approach avoids this problem because it's creating a Subscription as a separate CloudFormation resource - if anything, the 'concession' I made to modify the Topic for backwards compatibility might not be a good idea because it could run in to the problem you linked. Hmm.

MatthewDaniels · 2017-02-13T05:44:30Z

I know this ticket is closed, but I ran into this problem in version 1.6.1 and found this issue after a quick Google... so just to add a little more info to this ticket - I having this problem on a service that was deploying fine earlier today. I realised that I was in a different terminal window, which was using NodeJS version 7.0.0 vs NodeJS version 4.3.2.

Switching to the older version of nodejs (I use NVM to manage my node versions), immediately fixed the problem with no changes to the YML.

pmuens · 2017-02-13T08:03:45Z

Thanks for the tip @MatthewDaniels 👍

jaikdean · 2017-02-28T17:35:19Z

I'm also having this issue with Node 7.6.0, like @MatthewDaniels.

uday4393 · 2018-02-21T16:13:12Z

Any Update regarding this?
Whats the Fix.
Is this Fixed in the new serverless version?

pmuens added exp/beginner bug good first issue and removed exp/beginner labels Nov 18, 2016

dougmoscrop mentioned this issue Nov 25, 2016

add Support for SNS Subscription to existing topics #2796

Merged

7 tasks

pmuens added this to the 1.6 milestone Dec 22, 2016

eahefnawy closed this as completed in #2796 Jan 25, 2017

jthomerson mentioned this issue Jan 29, 2017

YML Does Not Allow Tags, Especially ImportValue #3162

Closed

matthisk mentioned this issue May 24, 2017

Cross region SNS trigger #3676

Closed

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

SNS event compiler tries to use an existing ARN as a topic name #2183

SNS event compiler tries to use an existing ARN as a topic name #2183

danielkoo commented Sep 22, 2016 •

edited

johncmckim commented Oct 5, 2016

johncmckim commented Oct 5, 2016

eahefnawy commented Oct 5, 2016

jthomerson commented Oct 16, 2016

alexef commented Oct 21, 2016

johncmckim commented Oct 22, 2016

viz commented Nov 9, 2016

jschr commented Nov 10, 2016 •

edited

gmetzker commented Dec 13, 2016

dougmoscrop commented Dec 20, 2016

gmetzker commented Dec 20, 2016 •

edited

dougmoscrop commented Dec 20, 2016

MatthewDaniels commented Feb 13, 2017 •

edited

pmuens commented Feb 13, 2017

jaikdean commented Feb 28, 2017

uday4393 commented Feb 21, 2018

SNS event compiler tries to use an existing ARN as a topic name #2183

SNS event compiler tries to use an existing ARN as a topic name #2183

Comments

danielkoo commented Sep 22, 2016 • edited

This is a Bug Report

Description

Additional Data

johncmckim commented Oct 5, 2016

johncmckim commented Oct 5, 2016

eahefnawy commented Oct 5, 2016

jthomerson commented Oct 16, 2016

alexef commented Oct 21, 2016

johncmckim commented Oct 22, 2016

viz commented Nov 9, 2016

jschr commented Nov 10, 2016 • edited

gmetzker commented Dec 13, 2016

dougmoscrop commented Dec 20, 2016

gmetzker commented Dec 20, 2016 • edited

dougmoscrop commented Dec 20, 2016

MatthewDaniels commented Feb 13, 2017 • edited

pmuens commented Feb 13, 2017

jaikdean commented Feb 28, 2017

uday4393 commented Feb 21, 2018

danielkoo commented Sep 22, 2016 •

edited

jschr commented Nov 10, 2016 •

edited

gmetzker commented Dec 20, 2016 •

edited

MatthewDaniels commented Feb 13, 2017 •

edited