additional runners that we could look at including

[tomeichlersmith]

I haven't done a very exhaustive search, but I have stumbled upon other runners that may be useful for denv to support.

• lilipod is a container manager focused on pulling images, managing images, and running containers. It was created as a simple/light backend for distrobox and so it naturally works as a runner for denv as well.
• charliecloud is a container manager focused on bringing easy-to-manage containers to HPCs. This manager is appealing to me since I could see it ending up on HPCs due to its security-focused design similar to singularity/apptainer.

[tomeichlersmith]

Did some charliecloud investigation, here are my notes

• need to use --write with ch-run so we can create the destination directories when --bind
  • we could avoid --write and use the pre-created /mnt/[0-9] but then users would need to get used to the paths changing within the denv which I'd like to avoid
  • I actually kinda like this explicit-ness for mounting from the host into the container, but it does make the containerized environment more difficult to use
• need to create a dir formatted image so we can use --write
• can't use --home because that tries to --bind ${workspace}:/home/$USER in the container which is not what we want (and fails if /home/$USER doesn't exist in the image)
• --bind and --set-env allows us to do the mounting and environment setup as need be

In a simple ubuntu server VM.

wget -q -O - https://github.com/hpc/charliecloud/releases/download/v0.35/charliecloud-0.35.tar.gz \
  | tar xzf -
cd charliecloud-0.35
./configure.sh
make
sudo make install
cd examples/hello
ch-image build . # infers name as name of directory
cd ../..
mkdir tutorial
cd tutorial
ch-convert -o dir hello hello
ch-run --write --cd=${PWD} --bind ${PWD} --set-env=HOME=${PWD} -- /bin/bash

[tomeichlersmith]

I can't get squashfuse internal mounting to work on Ubuntu because charliecloud requires libfuse3 while the squashfuse installable on Ubuntu 22.04 uses libfuse2.

tom@ch-playground:~/charliecloud-0.35$ sudo apt install libsquashfuse-dev
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
The following additional packages will be installed:
  libfuse2 libsquashfuse0
The following NEW packages will be installed:
  libfuse2 libsquashfuse-dev libsquashfuse0
0 upgraded, 3 newly installed, 0 to remove and 45 not upgraded.
Need to get 146 kB of archives.
After this operation, 628 kB of additional disk space will be used.
Do you want to continue? [Y/n] n
Abort.

I'm unsure on how to proceed from here although I suppose I could try to roll my own build of squashfuse.