OCPBUGS-62790: Use separate fs for ostree checkout on live ISO

Installations using ABI/assisted with 16GiB of RAM on the bootstrap node
were failing with "no space left on device" during bootstrapping. The
live ISO environment uses a tmpfs mounted at /var that is sized at 50%
of available RAM. On systems with 16GiB of RAM, this provides only 8GiB
of tmpfs space.

At the beginning of the bootstrap process, node-image-pull.sh creates an
ostree checkout underneath /var/ostree-container. When this is added to
the regular disk space usage of the later parts of the bootstrap, the
peak tmpfs usage hits around 9.4GiB.

This fix creates a separate 5GiB tmpfs to house /var/ostree-container,
so that it is not subject to the limits on the size of /var.

Author: zaneb

data/data/bootstrap/files/etc/systemd/system/node-image-pull.service

@@ -1,5 +1,6 @@
 [Unit]
 Description=Node Image Pull
+WantsMountsFor=/var/ostree-container
 Requires=network.target NetworkManager.service
 After=network.target
 

data/data/bootstrap/files/etc/systemd/system/ostree-mkfs.service

@@ -0,0 +1,11 @@
+[Unit]
+ConditionPathExists=/run/ostree-live
+RequiresMountsFor=/run/ostree_base
+
+[Service]
+Type=oneshot
+RemainAfterExit=true
+
+ExecStart=/bin/bash -c 'set -eu; /bin/truncate -s $$(($$(stat -f -c "%%b * %%s / 1024" /run/ostree_base)))k /run/ostree_base/loopfs'
+ExecStart=/sbin/mkfs.xfs /run/ostree_base/loopfs
+ExecStart=/bin/mkdir /var/ostree-container

data/data/bootstrap/files/etc/systemd/system/run-ostree_base.mount

@@ -0,0 +1,9 @@
+[Unit]
+RequiresMountsFor=/run
+ConditionPathExists=/run/ostree-live
+
+[Mount]
+What=tmpfs
+Where=/run/ostree_base
+Type=tmpfs
+Options=size=5G

data/data/bootstrap/files/etc/systemd/system/var-ostree\x2dcontainer.mount

@@ -0,0 +1,10 @@
+[Unit]
+ConditionPathExists=/run/ostree-live
+Requires=ostree-mkfs.service
+After=ostree-mkfs.service
+
+[Mount]
+What=/run/ostree_base/loopfs
+Where=/var/ostree-container
+Type=xfs
+Options=loop,discard