nixcfg/sshtool

#!/usr/bin/env bash

CMDFILE="$1"
if [ -z "$CMDFILE" ] || [ ! -f "$CMDFILE" ]; then
	echo "sshtool is not meant to be called on its own."
	echo "See scripts that use it (e.g. deploy_nixos) for usage examples."
	exit 1
fi
shift 1

cd $(dirname $CMDFILE)
CMDFILE=./$(basename $CMDFILE)

CLUSTER="$1"
if [ -z "$CLUSTER" ] || [ ! -d "cluster/$CLUSTER" ]; then
	echo "Usage: $CMDFILE <cluster name> [host1] [host2] [...]"
	echo "The cluster name must be the name of a subdirectory of cluster/"
	exit 1
fi
shift 1

if [ -z "$1" ]; then
	NIXHOSTLIST=$(ls cluster/$CLUSTER/node | grep '\.nix$' | grep -v '\.site\.')
else
	NIXHOSTLIST="$@"
fi

if [ -z "$ROOT_PASS" ]; then
	read -r -s -p "Enter remote sudo password: " ROOT_PASS
	echo
fi

SSH_CONFIG=cluster/$CLUSTER/ssh_config

function header {
	RANDNAME=$(openssl rand -hex 12)
	cat <<EOF
cat > /tmp/deploytool_askpass_$RANDNAME <<EOG
#!/usr/bin/env sh
echo "\\\$DEPLOYTOOL_ROOT_PASSWORD" | base64 -d
EOG
chmod +x /tmp/deploytool_askpass_$RANDNAME
export SUDO_ASKPASS=/tmp/deploytool_askpass_$RANDNAME
export DEPLOYTOOL_ROOT_PASSWORD=$(echo $ROOT_PASS | base64)
sudo -A sh - <<'EOEVERYTHING'
set -e
EOF
}

function footer {
	echo rm -v '/tmp/deploytool_askpass*'
	echo EOEVERYTHING
}

function message {
	echo "base64 -d <<EOG"
	echo "$@" | base64
	echo "EOG"
}

function cmd {
	echo "echo '- run $@'"
	echo "$@"
}

function set_env {
	echo "echo '- set $@'"
	echo "export $@"
}

function copy {
	local FROM=$1
	local TO=$2
	cat <<EOF
echo '- write $TO from $FROM'
base64 -d <<EOG | tee $TO > /dev/null
$(base64 <$FROM)
EOG
EOF
}

function copy_secret {
	local FROM=$1
	local TO=$2
	cat <<EOF
echo '- write secret $TO from $FROM'
base64 -d <<EOG | tee $TO > /dev/null
$(base64 <$FROM)
EOG
chown root:root $TO
chmod 0600 $TO
EOF
}

function write_pass {
	local PASSKEY=$1
	local TO=$2
	cat <<EOF
echo '- write secret $TO from pass $PASSKEY'
base64 -d <<EOG | tee $TO > /dev/null
$(pass $PASSKEY | base64)
EOG
chown root:root $TO
chmod 0600 $TO
EOF
}

function pipe_pass {
	local PASSKEY=$1
	local CMD=$2
	cat <<EOF
echo '- pipe secret $PASSKEY to command $CMD'
base64 -d <<EOG | $CMD > /dev/null
$(pass $PASSKEY | base64)
EOG
EOF
}

for NIXHOST in $NIXHOSTLIST; do
	NIXHOST=${NIXHOST%.*}

	if [ -z "$SSH_USER" ]; then
		SSH_DEST=$NIXHOST
	else
		SSH_DEST=$SSH_USER@$NIXHOST
	fi

	echo "==== DOING $NIXHOST ===="

	(header; . $CMDFILE; footer) | ssh -F $SSH_CONFIG $SSH_DEST sh -
done