fixes mostly for bootstrap vol, better docs

[automated-distro-installer] / fai / config / files / root / fai-check / VOL_STABLE_BOOTSTRAP

diff --git a/fai/config/files/root/fai-check/VOL_STABLE_BOOTSTRAP b/fai/config/files/root/fai-check/VOL_STABLE_BOOTSTRAP
new file mode 100755 (executable)
index 0000000..7621bdf
--- /dev/null
+++ b/fai/config/files/root/fai-check/VOL_STABLE_BOOTSTRAP
@@ -0,0 +1,89 @@
+#!/bin/bash
+
+set -eE -o pipefail
+trap 'echo "$0:$LINENO:error: \"$BASH_COMMAND\" returned $?" >&2' ERR
+
+
+
+usage() {
+    cat <<EOF
+Usage: ${0##*/} [OPTION]
+If grub var set, act like pxe rom and pxe-kexec to faiserver
+
+-f|--force  do kexec if we can reach faiserver
+-h|--help  Print help and exit.
+
+Note: Uses GNU getopt options parsing style
+EOF
+    exit $1
+}
+
+
+
+# Keep it short so we don't delay too much wnen we don't have networking.
+# In practice, on my home network, on an x200, it took 15 seconds, so
+# give it an extra 10 seconds, which seems fairly short as I write this.
+NETWORK_TIMOUT_SECS=25
+did_fai_check=false
+
+m() { printf "%s\n" "$*";  "$@"; }
+
+try-kexec() {
+    deadline=$(( `date +%s` + NETWORK_TIMOUT_SECS ))
+    while ! nc -zu faiserver 69; do
+        if (( `date +%s` > deadline )); then
+            echo "fai-check: hit $NETWORK_TIMOUT_SECS s tftp server timeout"
+            return 0
+        fi
+        sleep 1
+    done
+    m pxe-kexec -n --ignore-whitelist -l fai-generated faiserver ||:
+}
+
+case $1 in
+    -f|--force)
+        try-kexec
+        exit
+        ;;
+esac
+
+first=true
+for dev in $(btrfs fi show / | sed -rn 's#^\s*devid\s.*\s([^0-9 ]+)\S+$#\1#p' \
+                 |sort); do
+    dev+=4
+    mount $dev /mnt
+    if $first; then
+        if [[ -e /mnt/grubenv ]]; then
+            set -x
+            source <(grub-editenv /mnt/grubenv list)
+            set +x
+        fi
+        first=false
+        # we could just as well check if last_boot != /debianstable_boostrap
+        # the intent with this one is just a little clearer.
+        if [[ $did_fai_check == true ]]; then
+            grub-editenv /mnt/grubenv set did_fai_check=os_true
+            # our service does not wait for network-online.target,
+            # because it will wait for too long when we don't have a network
+            # connection. So, we wait for 10 seconds.
+            # ref: https://www.freedesktop.org/wiki/Software/systemd/NetworkTarget/
+            try-kexec
+        else
+            return 0
+        fi
+    else
+        # we make sure there is only 1 grubenv,
+        # so grub can just find the first one, in whatever order
+        # if looks at them, which may not be the same as us.
+        # If the disk dies, we just lose the default boot option,
+        # we will have to do manual steps to replace it anyways.
+        rm -f /mnt/gruvenv
+    fi
+    umount /mnt
+done
+
+# the check for last_boot is not needed afaik, just sanity check.
+if [[ $did_fai_check == true && $last_boot != /debianstable_boostrap ]]; then
+    # no need to reboot if we actually want to boot into this os.
+    reboot
+fi