[Storage] Storage mounting tool permissions fix

[romilbhardwaj]

Fixes test_aws_custom_image for #3211.

On certain images, chmod +x on /usr doesn't work:

e.g. on ami-062ddd90fb6f8267a

(base) ubuntu@ip-172-31-4-126:~/.sky$ sudo chmod 700 /usr/local/bin/goofys
(base) ubuntu@ip-172-31-4-126:~/.sky$ ls -lah /usr/local/bin/goofys
-rwx------ 1 root root 28M Apr  6  2022 /usr/local/bin/goofys

(base) ubuntu@ip-172-31-4-126:~/.sky$ sudo chmod +x /usr/local/bin/goofys
(base) ubuntu@ip-172-31-4-126:~/.sky$ ls -lah /usr/local/bin/goofys
-rwx------ 1 root root 28M Apr  6  2022 /usr/local/bin/goofys # Didn't work

(base) ubuntu@ip-172-31-4-126:~/.sky$ sudo chmod 755 /usr/local/bin/goofys
(base) ubuntu@ip-172-31-4-126:~/.sky$ ls -lah /usr/local/bin/goofys
-rwxr-xr-x 1 root root 28M Apr  6  2022 /usr/local/bin/goofys # chmod 755 works

same on gcp debian image and aws ubuntu image:

(base) gcpuser@mymntgcp-2ea4-head-arrpfaio-compute:/$ sudo chmod 700 /usr/local/bin/goofys
(base) gcpuser@mymntgcp-2ea4-head-arrpfaio-compute:/$ ls -lah /usr/local/bin/goofys
-rwx------ 1 root root 28M Apr  6  2022 /usr/local/bin/goofys

(base) gcpuser@mymntgcp-2ea4-head-arrpfaio-compute:/$ sudo chmod +x /usr/local/bin/goofys
(base) gcpuser@mymntgcp-2ea4-head-arrpfaio-compute:/$ ls -lah /usr/local/bin/goofys
-rwx--x--x 1 root root 28M Apr  6  2022 /usr/local/bin/goofys # Works!

This PR changes to use chmod 755.

Tested:

• pytest tests/test_smoke.py::test_aws_custom_image --aws
• pytest tests/test_smoke.py -k "test_aws_storage_mounts_with_stop" --aws
• pytest tests/test_smoke.py -k "test_gcp_storage_mounts_with_stop"

[Michaelvll]

Is it because the user we create on AWS is not in the same group as the root account, causing the sudo chmod +x only changes the permission for the root user, but not the current user (ubuntu)?
I think making it 755 should be fine, but just wondering if chmod +x without sudo will make it work?

Also it might be possible to add some config in the following to add the user into the same group, e.g.,

skypilot/sky/templates/aws-ray.yml.j2

Lines 103 to 109 in a081bb9

	users:
	- name: skypilot:ssh_user
	shell: /bin/bash
	sudo: ALL=(ALL) NOPASSWD:ALL
	ssh_authorized_keys:
	- |-
	skypilot:ssh_public_key_content

[romilbhardwaj]

hmm sudo chmod +x should grant execute permissions to all three -(u)ser, (g)roup and (o)thers. I tried with just chmod +x, but that won't work since the owner of the file is root. We could chown then chmod, but generally files in /usr are supposed to be owned by root...