Invalid principal in policy

[anuj9196]

My serverless.yml configuration:

plugins:
  - fullstack-serverless
  - serverless-offline

custom:
  namePrefix: ${self:provider.stage}-${self:provider.region}
  fullstack:
    bucketName: serverless-${self:custom.namePrefix}-frontend
    distributionFolder: webapp/dist/webapp
    singlePageApp: true
    clientCommand: npm install && ng build --aot --prod
    clientSrcPath: webapp

But on deploying, it gives error

Serverless Error ---------------------------------------
 
  An error occurred: WebAppS3BucketPolicy - Invalid principal in policy (Service: Amazon S3; Status Code: 400; Error Code: MalformedPolicy; Request ID: EE986697DF548390; S3 Extended Request ID: 0c648uKWw85q+U9bTsGXoCUzUFT21wpDPFYjkwYw2RPEh1nfq83xXmjtVAuHmoTeGo8uPQOhhzM=).

The errors generating are random.

When there was no bucketName in the config, it was giving an error as

Bucket name should not contain uppercase characters

Sometimes, it gives

client generation failed

[hakimio]

Try to run sls package and inspect the generated cloudformation template.
Maybe, you misspelled some of the parameters or they don't exist ${self:provider.stage}, ${self:provider.region}, ${self:custom.namePrefix}.
Also, you can load the cloudformation template into cloudformation visual editor and run the automatic inspection there.

[andrewphahn]

Were you able to resolve the first issue? If not can you share the generated cloudformation template (in the .serverless folder).

The second issue

When there was no bucketName in the config, it was giving an error as

It should actually fail with 'Please specify a bucket name for the client in serverless.yml', but maybe providing a default that works would be a better solution. It will just be a change to lib/resources/resources.yml to change that and remove the validation (that is apparently broken) in lib/validate.js.