feat: add mail-in-ctr util

Author: computator

utils/mail-in-ctr.sh

@@ -0,0 +1,83 @@
+#!/bin/sh
+# Proxy to s-nail mail/mailx inside smtp container
+: ${CTR_NAME:=smtp-proxy}
+SELF_NAME=mail-in-ctr
+
+SHORT_OPTS='dEhntvVa:b:c:q:r:s:T:'
+LONG_OPTS='debug,discard-empty-messages,help,template,verbose,version'$(\
+         )',attach:,bcc:,cc:,quote-file:,from-address:,subject:,target:'
+
+arg_quot () {
+	# test'asdf"blah -> 'test'\''asdf"blah'
+	printf '%s' "$@" | sed "s/'/'\\\\''/g; s/.*/'&'/"
+}
+
+if [ "$(getopt -T > /dev/null; echo $?)" -eq 4 ]; then
+	# sed is to strip the extra -- param
+	orig_opts=$(getopt -- '' -- "$@" | sed 's/^ *-- *//')
+	# convert -. and --end-options to --
+	eval set -- "$(echo "$orig_opts" | sed -E "s/' *(-\.|--end-options) *'/--/")"
+	opts=$(getopt -n $SELF_NAME -l "$LONG_OPTS" -- "$SHORT_OPTS" "$@") || exit
+	eval set -- "$opts"
+	out_opts=
+	while true; do
+		case "$1" in
+			# safe flags
+			-d|--debug|\
+			-E|--discard-empty-messages|\
+			-n|\
+			-t|--template|\
+			-v|--verbose|\
+			-V|--version)
+				out_opts="$out_opts $1"
+				shift
+				;;
+
+			# safe params
+			-b|--bcc|\
+			-c|--cc|\
+			-r|--from-address|\
+			-s|--subject|\
+			-T|--target)
+				out_opts="$out_opts $1 $(arg_quot "$2")"
+				shift 2
+				;;
+
+			# special
+			-a|--attach)
+				echo "ERROR: $SELF_NAME: attachments are unsupported" >&2
+				exit 1
+				;;
+			-h|--help)
+				out_opts='--help'
+				break
+				;;
+			-q|--quote-file)
+				if [ "$2" != '-' ]; then
+					echo "ERROR: $SELF_NAME: only '-' for stdin is supported with '$1'" >&2
+					exit 1
+				fi
+				out_opts="$out_opts -q -"
+				shift 2
+				;;
+
+			# end of options
+			--) shift; break;;
+
+			*)
+				echo "ERROR: $SELF_NAME: unhandled paramater '$1'" >&2
+				exit 1
+				;;
+		esac
+	done
+	if [ "$out_opts" = '--help' ]; then
+		eval set -- --help
+	else
+		out_opts=${out_opts# }
+		eval set -- "$out_opts" -. '"$@"'
+	fi
+else
+	echo "WARNING: $SELF_NAME: falling back to insecure parameter passing because this getopt is unsupported" >&2
+fi
+
+exec ${CTR_EXEC_CMD:-podman exec} -i "$CTR_NAME" mail "$@"