Pull image if missing when enabling module in so-learn

salt/common/tools/sbin/so-image-pull

@@ -0,0 +1,48 @@
+#!/bin/bash
+#
+# Copyright 2014,2015,2016,2017,2018,2019,2020,2021 Security Onion Solutions, LLC
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+. /usr/sbin/so-common
+. /usr/sbin/so-image-common
+
+usage() {
+	read -r -d '' message <<- EOM
+		usage: so-image-pull [-h] IMAGE [IMAGE ...]
+
+		positional arguments:
+			IMAGE         One or more 'so-' prefixed images to download and verify.
+
+		optional arguments:
+			-h, --help    Show this help message and exit.
+	EOM
+	echo "$message"
+	exit 1
+}
+
+if [[ $# -eq 0 || $# -gt 1 ]] || [[ $1 == '-h' || $1 == '--help' ]]; then
+	usage
+fi
+
+TRUSTED_CONTAINERS=("$@")
+set_version
+
+for image in "${TRUSTED_CONTAINERS[@]}"; do
+	if ! docker images | grep "$image" | grep ":5000" | grep -q "$VERSION"; then
+		update_docker_containers "$image" "" "" ""
+	else
+		echo "$image:$VERSION image exists." 1>&2
+	fi
+done