Controller

A Juju controller has two basic persistent storage needs: database access and blob storage. MongoDB satisfied both. However, Dqlite will only satisfy the former – for blob storage the Juju controller will require an external object store.

By default, Juju will use the filesystem of the controller’s supporting infrastructure. However, you can also use object-store-related controller configuration keys to specify any object store (highly recommended in a production setting!) you want, so long as it is S3-compatible (e.g., AWS S3, MicroCeph, MinIO, etc.), either during bootstrap or later.

Also, Juju will apply default S3 policy permissions, but you are free to change them, so long as they satisfy the following as a minimum (at least, during model creation):

{
   "Version" : "2012-10-17",
   "Statement" : [
      {
         "Effect" : "Allow",
         "Action" : [ 
            "s3:CreateBucket",
            "s3:PutBucketPolicy",
            "s3:PutBucketTagging",
            "s3:PutBucketVersioning",
            "s3:PutBucketObjectLockConfiguration"
         ],
         "Resource" : "arn:aws:s3:::*"
      },
      {
         "Effect" : "Allow",
         "Action" : [ 
            "s3:ListBucket",
            "s3:ListBucketVersions",
            "s3:ListAllMyBuckets",
            "s3:GetBucketLocation",
            "s3:GetBucketPolicy",
            "s3:GetBucketTagging",
            "s3:GetBucketVersioning",
            "s3:GetBucketObjectLockConfiguration",
            "s3:GetObject",
            "s3:GetObjectLegalHold",
            "s3:GetObjectRetention",
            "s3:PutObject",
            "s3:PutObjectLegalHold",
            "s3:BypassGovernanceRetention", 
            "s3:PutObjectRetention",
            "s3:DeleteObject"
         ],
         "Resource" : "arn:aws:s3:::*"
      }
   ]
}