Serverless: Deplyment error S3 Bucket already exists in stack - amazon-web-services

Question

I am trying to deploy a serverless project which has s3 bucket creation cloudformation in the serverless.yml file, but the problem is when I tried to deploy, it says the s3 bucket already exists and failing the deployment.
I know s3 bucket name should be globally unique, and I am damn sure it is a unique name that I am using, even if changed to something else, it still says the same.
the cloudformation stack it says the s3 bucket exists is actually the newly created stack, not sure how to fix this issue. can anyone help me out with this issue and tell me how to fix the deployment issue and the cause for the issue :).
Thanks in advance.

Answer 1

The issue I had was, for one of the lambdas I had the above-mentioned bucket as the event source, so when some bucket is added as event source it actually creating that bucket as well, therefore when it runs the actual creation related cloudformation it is saying the bucket already exists.
So I fixed it by only keeping the event source and removed the actual declaration of that bucket.

Answer 2

If you add existing: true to the S3 config in your serverless.yml file it won't try to create the S3 bucket like the below:-
funcName:
handler: handler
events:
- s3:
bucket: 'my-bucket-name'
events: s3:ObjectCreated:*
existing: true
rules:
- suffix: .pdf
- prefix: documents

Answer 3

Anything involving CloudFormation (or any other infrastructure-in-code) is fussy, and the error messages can mislead, meaning there are a ton of things that can cause this problem (see issues on GitHub like this one).
But in my experience, the most common causes of these kind of problems are are not the pre-existing bucket, but problems with AWS credentials, permissions, or region that give misleading error messages. To fix these, or at least rule them out:
Make sure your serveless.yml is set to the region you already deployed the stack in. Example:
custom:
stage: dev
region: us-east-2
Override any latent credentials from, for example, ~/.aws/credentials, by explicitly setting your credentials in the shell you'll use to deploy. Example from the Serverless docs:
export AWS_ACCESS_KEY_ID=<your access key here>
export AWS_SECRET_ACCESS_KEY=<your access secret here.
Make sure those AWS credentials have the roles and permissions they need.
But, as I mentioned, CloudFormation is fussy. There may be other problems to solve, but try these first. You may try them and still be beating your head against the wall, but it'll more likely be the right wall. Hope this helps.

Answer 4

Try to use Conditional statements and pass them as a Parameter to create the bucket or not
AWSTemplateFormatVersion: 2010-09-09
Parameters:
EnvType:
Description: Environment type.
Default: test
Type: String
AllowedValues:
- prod
- test
ConstraintDescription: must specify prod or test.
Conditions:
CreateProdResources: !Equals
- !Ref EnvType
- prod
Resources:
EC2Instance:
Type: 'AWS::EC2::Instance'
Properties:
ImageId: ami-0ff8a91507f77f867
MountPoint:
Type: 'AWS::EC2::VolumeAttachment'
Condition: CreateProdResources
Properties:
InstanceId: !Ref EC2Instance
VolumeId: !Ref NewVolume
Device: /dev/sdh
NewVolume:
Type: 'AWS::EC2::Volume'
Condition: CreateProdResources
Properties:
Size: 100
AvailabilityZone: !GetAtt
- EC2Instance
- AvailabilityZone
Follow the sample condition flow to decide wheather to create a resource or not.
See this for more details

Answer 5

When deploying, the BucketName must be unique across all regions. So if anyone has already created a bucket with "local-bucket-dev," it will throw
An error occurred: AttachmentsBucket - local-bucket-dev already
exists.
Try to just the BucketName to be unique.
I hope that helps.