AWS elasticache redis sharding configuration - amazon-web-services

Question

I have two AWS accounts, Prod and Staging. I need to migrate data from prod elasticache redis to staging. The Redis clusters in prod and staging are both 1 node and 0 shards each. I believe you cant update an already running cluster so I'm trying to
seed a new cluster with the RDB file with the same cluster configuration as already exists in staging, with a view to deleting the original staging cluster after the new one stands up
Problem is every time I go through the console and create a Redis cluster it stands up with 1 shard and 1 node. The original cluster had 0 shards. I selected 0 number of replicas, no multi AZ etc so I'm not sure why its defaulting to sharding. Am I missing an option somewhere, are you able to stand up a 1 node 0 shard cluster via the console?
I also tried creating a cluster via the AWS CLI to see if i get the same behaviour but get the error message:
An error occurred (InvalidParameterValue) when calling the CreateCacheCluster operation: No permission to access S3 object: mybucket/folder/file.rdb
I've set the bucket policy to the following:
{
"Version": "2012-10-17",
"Statement": [
{
"Sid": "1",
"Effect": "Allow",
"Principal": {
"AWS": "arn:aws:iam::0123456789:root"
},
"Action": "s3:ListBucket",
"Resource": "arn:aws:s3:::mybucket"
},
{
"Sid": "2",
"Effect": "Allow",
"Principal": {
"AWS": "arn:aws:iam::0123456789:root"
},
"Action": [
"s3:PutObject",
"s3:GetObject"
],
"Resource": "arn:aws:s3:::mybucket/*"
},
{
"Sid": "ExampleStatement",
"Effect": "Allow",
"Principal": {
"AWS": "arn:aws:iam::0123456789:user/my-user"
},
"Action": "s3:*",
"Resource": [
"arn:aws:s3:::mybucket",
"arn:aws:s3:::mybucket/*",
"arn:aws:s3:::mybucket/folder/file.rdb"
]
},
{
"Sid": "Stmt15399483",
"Effect": "Allow",
"Principal": {
"Service": "eu-west-1.elasticache-snapshot.amazonaws.com"
},
"Action": [
"s3:GetObject",
"s3:ListBucket",
"s3:GetBucketAcl"
],
"Resource": [
"arn:aws:s3:::mybucket",
"arn:aws:s3:::mybucket/*",
"arn:aws:s3:::mybucket/folder/file.rdb"
]
}
]
}
Note this policy is in the permissions tab of the top level bucket. when i click on the file there is no area to add/edit a bucket policy only an ACL edit option. I did grant elasticache canonical ID read/write as it suggests in the AWS docs but still get permission denied

Answer 1

I was able to get the cluster configuration (1 node 0 shards) by using the CLI command:
aws elasticache delete-replication-group --replication-group-id my-cluster --retain-primary-cluster
although this requires running the command after cluster creation. I'm hoping theres a way to select this config at creation time