feat: [NODE-1529] Add swap to GuestOS

ic-os/components/early-boot/fstab/fstab-guestos

@@ -7,3 +7,4 @@ tmpfs    /tmp    tmpfs   defaults 0   2
 /dev/mapper/store-shared--backup   /var/lib/ic/backup    ext4 defaults,context=system_u:object_r:ic_data_t:s0   0   2
 /dev/mapper/store-shared--crypto   /var/lib/ic/crypto    ext4 defaults   0   2
 /dev/mapper/store-shared--data   /var/lib/ic/data    xfs defaults   0   2
+/dev/mapper/store-shared--swap   none    swap defaults   0   2

ic-os/components/guestos.bzl

@@ -152,6 +152,8 @@ component_files = {
     Label("upgrade/shared-resources/setup-shared-resources/setup-shared-crypto.service"): "/etc/systemd/system/setup-shared-crypto.service",
     Label("upgrade/shared-resources/setup-shared-resources/setup-shared-data.sh"): "/opt/ic/bin/setup-shared-data.sh",
     Label("upgrade/shared-resources/setup-shared-resources/setup-shared-data.service"): "/etc/systemd/system/setup-shared-data.service",
+    Label("upgrade/shared-resources/setup-shared-resources/setup-shared-swap.sh"): "/opt/ic/bin/setup-shared-swap.sh",
+    Label("upgrade/shared-resources/setup-shared-resources/setup-shared-swap.service"): "/etc/systemd/system/setup-shared-swap.service",
     Label("upgrade/systemd-generators/guestos/mount-generator"): "/etc/systemd/system-generators/mount-generator",
     Label("upgrade/systemd-generators/systemd-gpt-auto-generator"): "/etc/systemd/system-generators/systemd-gpt-auto-generator",
     Label("upgrade/manageboot/manageboot.sh"): "/opt/ic/bin/manageboot.sh",

ic-os/components/init/setup-lvs/guestos/setup-lvs.sh

@@ -65,3 +65,18 @@ lvs /dev/store/shared-backup >/dev/null 2>&1 || (
     fi
     retry lvcreate --yes -L "$LV_SIZE"M -n shared-backup store
 )
+
+# Set up swap space if it does not exist yet.
+lvs /dev/store/shared-swap >/dev/null 2>&1 || (
+    echo "Logical volume 'shared-swap' does not exist yet (first boot?), creating it."
+    TOTAL_SIZE=$(($(blockdev --getsz /dev/mapper/vda10-crypt) * 512))
+    # Limit to 64G or 14% of capacity, whichever is lower.
+    # Note: The odd percentage makes calculation easier, and allows for a
+    # smaller swap when testing.
+    LV_SIZE=$(("$TOTAL_SIZE" / 7 / 1024 / 1024))
+    LV_SIZE_LIMIT=64000
+    if [ "${LV_SIZE}" -gt "${LV_SIZE_LIMIT}" ]; then
+        LV_SIZE="${LV_SIZE_LIMIT}"
+    fi
+    retry lvcreate --yes -L "$LV_SIZE"M -n shared-swap store
+)

ic-os/components/upgrade/shared-resources/setup-shared-resources/setup-shared-swap.service

@@ -0,0 +1,22 @@
+[Unit]
+Description=Setup shared-swap space
+DefaultDependencies=no
+Requires=dev-mapper-store\x2dshared\x2d\x2dswap.device
+After=dev-mapper-store\x2dshared\x2d\x2dswap.device
+Before=dev-mapper-store\x2dshared\x2d\x2dswap.swap
+# Add an explicit sequencing to LVM setup. The observed problem is that the
+# LV apparently becomes notified as "ready" through udev before the actual
+# lvcreate command has finished. This results in filesystem setup racing with
+# lvcreate performing a "wipe" of the LV, resulting in a destroyed filesystem
+# in turn.
+After=setup-lvs.service
+Requires=setup-lvs.service
+
+[Install]
+RequiredBy=systemd-fsck@dev-mapper-store\x2dshared\x2d\x2dswap.service
+WantedBy=local-fs.target
+
+[Service]
+Type=oneshot
+RemainAfterExit=true
+ExecStart=/opt/ic/bin/setup-shared-swap.sh

ic-os/components/upgrade/shared-resources/setup-shared-resources/setup-shared-swap.sh

@@ -0,0 +1,7 @@
+#!/bin/bash
+
+set -e
+
+blkid /dev/mapper/store-shared--swap >/dev/null || (
+    mkswap /dev/mapper/store-shared--swap
+)