Add script that creates AppStream image programmatically

[milanmlft]

Create Your AppStream 2.0 Image Programmatically by Using the Image Assistant CLI Operations - Amazon AppStream 2.0

[milanmlft]

This guide might be useful to mount an EFS volume in the AppStream instance for shared file access.

[davecash75]

This looks somewhat similar to what I think I did on Appstream. I didn't figure out Security Groups though to get write-access

[milanmlft]

Hmm yes it's not working straight away for me either. Something is going wrong with the mounting, I just get an empty /efs/ directory... Will do some more digging today.

[davecash75]

I have the following in /opt/appstream/SessionScripts/efs-mount.sh on my VM:

#!/bin/bash
sudo mkdir /data
sudo mount -t nfs4 -o nfsvers=4.1,rsize=1048576,wsize=1048576,hard,timeo=600,retrans=2,noresvport fs-0e4119c6017f3505e.efs.eu-west-2.amazonaws.com:/ /data

[davecash75]

For EC2, I did make an access point which seemed to work well.

[milanmlft]

I managed to get the mounting working. I also had to add a step to give users read & write permissions so they could see hte files. The only issue is this only applies to files already present in the XNAT directory. whenever XNAT creates new files (e.g. after running an analysis), those files are root owned with restricted permissions... So those files will not be accessible to users. This can be resolved by ssh'ing into the web-server EC2 instance and updating the file permissions with chmod, but this is obviously quite cumbersome...

I'm not aware of any way to get XNAT to create files with more relaxed permissions, but maybe @p-j-smith or @HChughtai know more?

[HChughtai]

Not off the top of my head. I think the expected workflow is that you would download the resources from the front-end (which I expect gets around the permissions issue) rather than access them directly on the server. You could try getting around this as the OS level and having newly created files inherit permissions from their parent folder. E.g. using ACL inheritance.