Fails to bind/mount a non existing dir in container

[osallou]

Version of Singularity:

2.3-dist

Expected behavior

Have in conf user bind control and enable overlay to yes

Expect to mount a local directory in container even if it does not exists in container

I am on CentOS 6.7

Actual behavior

as options are set as per doc explained, user should be able to mount a non existant directory in container.

Steps to reproduce behavior

./singularity/bin/singularity   shell -B /omaha-beach/xx:/opt/xx  centos-latest.img

[vsoch]

hey @osallou ! Could you please provide output with --debug? The above seems to work ok for me:

 singularity   shell -B /home/vanessa/Desktop:/opt/xx  centos-latest.img 
Singularity: Invoking an interactive shell within container...

Singularity centos-latest.img:~> ls /opt
xx

(I apologize I know that's the worst message "hey it works for me!" but with debug we can start to figure out what is going on

[GodloveD]

I think that enable overlay = yes requires that Singularity be running on a host that implements an overlay file system. I don't think this is available in RHEL 6/CentOS 6. I believe it makes it's first appearance in RHEL 7/CentOS 7. Can anyone else verify?

[osallou]

could indeed by centos6 related , but many clusters/hpc do not have recent OS... :-(

[thiell]

I just ran into the same issue on a RHEL6.9-based cluster. overlayfs is actually supported in RHEL 7.1 as a tech preview only, so while it could work on a RHEL/CentOS 7-based host, it won't with a standard CentOS/RHEL 6 kernel, doh. Is there another way to do custom bind if files don't exist in the container?

[dtrudg]

Closing this - as noted overlay is not present on CentOS/RHEL6. If you need to bind into a container you will need to add the directory bind point to the container by building a new image, with mkdir in %post to add the required directories.