bento/populate_chroot.sh

#!/bin/sh

if test -f config.sh
then
    . ./config.sh
else
    echo "You are missing config.sh"
    exit 2
fi

if [ "$(id -u)" -ne 0 ]
then
  echo "you need to be root to run this script"
  exit 1
fi

cd hosts
# load all hosts or the one defined in environment variable NAME
if [ -z "$NAME" ]
then
  NAME=*
fi

for i in $NAME
do
    printf "Copying $i: "

    # we only want directories
    if [ -d "$i" ]
    then

        STAGING_DIR="$(mktemp -d /tmp/bento-staging-dispatch.XXXXXXXXXXXXXX)"

        # sftp chroot requires the home directory to be owned by root
        install -d -o root -g sftp_users -m 755 "${STAGING_DIR}"
        install -d -o root -g sftp_users -m 755 "${STAGING_DIR}/${i}"
        install -d -o root -g sftp_users -m 755 "${STAGING_DIR}/${i}/config"
        install -d -o ${i} -g sftp_users -m 755 "${STAGING_DIR}/${i}/logs"

        # copy files in the chroot
        rsync --delete -rltgoDL "$i/" "${STAGING_DIR}/${i}/config/"

        # create the script that will check for updates
        cat > "${STAGING_DIR}/${i}/config/update.sh" <<EOF
#!/bin/sh
set -e

install -d -o root -g root -m 700 /var/bento
cd /var/bento
touch .state

STATE="\$(echo "ls -l last_change_date" | sftp ${i}@${REMOTE_IP})"
CURRENT_STATE="\$(cat /var/bento/.state)"

if [ "\$STATE" = "\$CURRENT_STATE" ]
then
    echo "no update required"
else
    echo "update required"
    sftp ${i}@${REMOTE_IP}:/config/bootstrap.sh .
    /bin/sh bootstrap.sh
    echo "\$STATE" > /var/bento/.state
fi
EOF

        # script used to download changes and rebuild
        # also used to run it manually the first time to configure the system
        cat > "${STAGING_DIR}/${i}/config/bootstrap.sh" <<EOF
#!/bin/sh
set -e

# accept the remote ssh fingerprint if not already known
ssh-keygen -F "${REMOTE_IP}" >/dev/null || ssh-keyscan "${REMOTE_IP}" >> /root/.ssh/known_hosts

install -d -o root -g root -m 700 /var/bento
cd /var/bento

printf "%s\n" "cd config" "get -R ." | sftp -r ${i}@${REMOTE_IP}:

# for flakes
test -d .git || git init
git add .

# check the current build if it exists
if test -L result
then
    RESULT="\$(readlink -f result)"
fi

LOGFILE=\$(mktemp /tmp/build-log.XXXXXXXXXXXXXXXXXXXX)

SUCCESS=2
if test -f flake.nix
then
    nixos-rebuild build --flake .#bento-machine
    if [ ! "\${RESULT}" = "\$(readlink -f result)" ]
    then
        nixos-rebuild switch --flake .#bento-machine 2>&1 | tee \$LOGFILE
        SUCCESS=\$?
    else
        SUCCESS=nothing
    fi
else
    export NIX_PATH=/root/.nix-defexpr/channels:nixpkgs=/nix/var/nix/profiles/per-user/root/channels/nixos:nixos-config=/var/bento/configuration.nix:/nix/var/nix/profiles/per-user/root/channels
    nixos-rebuild build --no-flake --upgrade 2>&1 | tee \$LOGFILE
    if [ ! "\${RESULT}" = "\$(readlink -f result)" ]
    then
        nixos-rebuild switch --no-flake --upgrade 2>&1 | tee -a \$LOGFILE
        SUCCESS=\$?
    else
        SUCCESS=nothing
    fi
fi

gzip -9 \$LOGFILE
#mv \$LOGFILE \$LOGFILE.gz
if [ ! "\$SUCCESS" = "nothing" ]
then
  if [ "\$SUCCESS" -eq 0 ]
  then
      echo "put \${LOGFILE}.gz /logs/\$(date +%Y%m%d-%H%M)-success.log.gz" | sftp ${i}@${REMOTE_IP}:
  else
      echo "put \${LOGFILE}.gz /logs/\$(date +%Y%m%d-%H%M)-failure.log.gz" | sftp ${i}@${REMOTE_IP}:
  fi
fi
EOF

        # to make flakes using caching, we must avoid repositories to change everytime
        # we must ignore files that change everytime
        cat > "${STAGING_DIR}/${i}/config/.gitignore" <<EOF
bootstrap.sh
update.sh
.state
result
last_change_date
EOF

        # only distribute changes if they changed
        # this avoids bumping the time and trigger a rebuild for nothing
        diff -r "${STAGING_DIR}/${i}/config/" "${CHROOT_DIR}/${i}/config/" >/dev/null
        CHANGES=$?

        if [ "$CHANGES" -ne 0 ]
        then
            echo " update"
            # copy files in the chroot
            install -d -o root -g sftp_users -m 755 "${CHROOT_DIR}"
            install -d -o root -g sftp_users -m 755 "${CHROOT_DIR}/${i}"
            install -d -o root -g sftp_users -m 755 "${CHROOT_DIR}/${i}/config"
            install -d -o ${i} -g sftp_users -m 755 "${CHROOT_DIR}/${i}/logs"
            rsync --delete -rltgoDvL "${STAGING_DIR}/${i}/config/" "${CHROOT_DIR}/${i}/config/"
            touch "${CHROOT_DIR}/${i}/last_change_date"
        else
            echo " no changes"
        fi

        rm -fr "${STAGING_DIR}"
    fi
done