feat: initial pass at supporting podmansh (#412)

Co-authored-by: Jorge O. Castro <jorge.castro@gmail.com>

usr/share/ublue-os/just/custom.just

@@ -148,6 +148,25 @@ nix-devbox-global:
   echo 'run "devbox global run" to see other available configuration commands'
 
 # Install better touch-friendly GNOME extensions
+podmansh:
+  sudo mkdir -p /etc/containers/systemd/users/${UID}
+  sudo cp /usr/share/ublue-os/quadlets/podmansh.container /etc/containers/systemd/users/${UID}/podmansh.container
+  sudo lchsh $USER /usr/bin/podmansh
+  podman pull ghcr.io/ublue-os/ubuntu-toolbox:latest
+
+  systemctl --user daemon-reload
+  systemctl --user start podmansh.service
+  echo "Shell now switched to podmansh. Spawn a new terminal to get going!"
+  echo "By default, the shell will be Bash. To override it, create ~/.profile with your preferred shell"
+  echo "Note: That shell must exist in the toolbox!"
+
+podmansh-switch IMAGE:
+  sudo sed -i "/Image\=.*$/c Image\={{IMAGE}}" /etc/containers/systemd/users/${UID}/podmansh.container
+  podman pull {{IMAGE}}
+  podman rm -f podmansh
+  systemctl --user daemon-reload
+  systemctl --user start podmansh.service
+  echo "Image now switched to {{IMAGE}}"
 touch:
   pip install --upgrade gnome-extensions-cli
   gext install improvedosk@nick-shmyrev.dev

usr/share/ublue-os/quadlets/podmansh.container

@@ -0,0 +1,41 @@
+[Unit]
+Description=The Podmansh container
+After=local-fs.target
+
+[Container]
+Image=ghcr.io/ublue-os/ubuntu-toolbox:latest
+ContainerName=podmansh
+RemapUsers=keep-id
+RunInit=yes
+Network=host
+AddCapability=all
+NoNewPrivileges=no
+Exec=sleep infinity
+WorkingDir=%h
+
+Volume=%h:%h
+Volume=/:/run/host:rslave
+Volume=/dev:/dev:rslave
+Volume=/sys:/sys:rslave
+Volume=/tmp:/tmp:rslave
+Volume=/sys/fs/selinux
+Volume=/var/log/journal
+Volume=/run/user/1000:/run/user/1000:rslave
+Volume=/etc/hosts:/etc/hosts:ro
+Volume=/etc/resolv.conf:/etc/resolv.conf:ro
+
+Environment=ENV=%h/.profile
+
+PodmanArgs=--env-host
+PodmanArgs=--privileged
+PodmanArgs=--mount=type=devpts,destination=/dev/pts
+PodmanArgs=--userns=keep-id
+PodmanArgs=--ulimit=host
+PodmanArgs=--security-opt=label=disable
+PodmanArgs=--cgroupns=private
+PodmanArgs=--log-level=debug
+
+Annotation=run.oci.keep_original_groups=1
+
+[Install]
+RequiredBy=default.target