Describe the problem

Autoscaler launch currently doesn't work on workers if the following command is run:

• most_recent() { echo pip install -U https://s3-us-west-2.amazonaws.com/ray-wheels/$(aws s3 ls s3://ray-wheels --recursive | grep $1 | sort -r | head -n 1 | awk '{print $4}'); } && $( most_recent "cp36-cp36m-manylinux1" ) || $( most_recent "cp35-cp35m-manylinux1" )

Plausible solutions:

1. Add a latest folder to the S3 wheels folder so that aws cli isn't needed on workers
2. Add more permissions to the head node so that worker nodes are endowed with permissions to read from S3