EC2 Image Builder Cloud Formation S3Download Source Issue

Question

I am using EC2 Image Builder using Cloud Formation. In that I am trying to download files inside a folder (or Prefix?) from an S3 bucket using the following syntax.
               
```
 - name: DownloadFiles
   action: S3Download
   onFailure: Abort
   maxAttempts: 3
   inputs:
       -  source: s3://myBucket/my-app/*
          destination: C:	emp\
```
However, in my s3 bucket called myBucket, I have 2 folders with the names my-app and my-app-prereq. Because of this, it seems to be downloading from both, instead of downloading from just my-app folder as specified in the Source attribute above. Can anyone please help me?

Answer

Did you recheck if it's actually downloading from both folders? It is expected to download all folders and files under the specified prefix with wildcard * according to the documentation https://docs.aws.amazon.com/imagebuilder/latest/userguide/toe-action-modules.html#action-modules-s3download

I recommend you If possible, to separate the folders into different hierarchies to eliminate the prefix ambiguity:

**s3://myBucket/app/my-app/  
s3://myBucket/app-prereq/my-app-prereq/**

Then, you can update your EC2 Image Builder CloudFormation YAML configuration as follows:

```yaml
  - name: DownloadFiles
    action: S3Download
    onFailure: Abort
    maxAttempts: 3
    inputs:
      - source: s3://myBucket/app/my-app/*
        destination: C:	emp\
```

EC2 Image Builder Cloud Formation S3Download Source Issue

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