CODEWITHSUNDEEP
serverless-framework
Josh
Josh

Reputation: 531

How do you make use of cloudformation outputs within serverless framework?

If you deploy a cloudformation creating a kinesis stream how can you provide the outputs such as an arn to a lambda created in the same deployment. Does cf happen before serverless creates the lambdas and is there a way to store the cloudformation values in the lambda?

Upvotes: 2

Views: 3523

Answers (2)

Matt D
Matt D

Reputation: 3496

To store the Arn from your CloudFormation Template "s-resource-cf.json", add some items into the "Outputs" section.

"Outputs": {
  "InsertVariableNameForLaterUse": {
    "Description": "This is the Arn of My new Kinesis Stream",
    "Value": {
      "Fn::GetAtt": [
        "InsertNameOfCfSectionToFindArnOf",
        "Arn"
      ]
     }
    }
   }

The Fn::GetAtt is a function in CF to get a reference from another resource being created.

When you deploy the CF Template using serverless resources deploy -s dev -r eu-west-1 the Kinesis Stream is created for that Stage/Region and the Arn will be saved into the region properties file /_meta/resources/variables/s-variables-dev-euwest1.json. Note the initial capitalisation change insertVariableNameForLaterUse.

You can then use that in the function's s-function.json as ${insertVariableNameForLaterUse}, such as the environment section:

"environment": {
  "InsertVariableNameWeWantToUseInLambda": "${insertVariableNameForLaterUse}"
  ...
}

and reference this variable in your Lambda using something like:

var myKinesisStreamArn = process.env.InsertVariableNameWeWantToUseInLambda;

CloudFormation happens before Lambda Deployments. Though you should probably control that with a script rather than just using the dashboard:

serverless resources deploy -s dev -r eu-west-1
serverless function deploy --a -s dev -r eu-west-1
serverless endpoint deploy --a -s dev -r eu-west-1

Hope that helps.

Upvotes: 3

rk2
rk2

Reputation: 1589

What are the steps of deployment you are following here from Serverless? For the first part of your ask, I believe you can do a 'sls resources deploy' to deploy all CF related resources, and then you do a 'sls function deploy' OR 'sls dash deploy' to deploy the lambda functions. So technically, resource deploy (CF) does not actually deploy lambda functions.

For the second part of your ask, if you have a use-case where you want to use the output of a CF resource being created, (as of now) this feature has been added/merged to v0.5 of Serverless which has not yet been released.

Upvotes: 0

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