add mongo:admin command

subcommands/admin

@@ -0,0 +1,22 @@
+#!/usr/bin/env bash
+source "$(dirname "$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)")/config"
+set -eo pipefail; [[ $DOKKU_TRACE ]] && set -x
+source "$PLUGIN_BASE_PATH/common/functions"
+source "$(dirname "$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)")/functions"
+
+mongo-admin-cmd() {
+  declare desc="connect via mongo to a $PLUGIN_SERVICE service as admin user"
+  local cmd="$PLUGIN_COMMAND_PREFIX:admin" argv=("$@"); [[ ${argv[0]} == "$cmd" ]] && shift 1
+  declare SERVICE="$1"
+
+  [[ -z "$SERVICE" ]] && dokku_log_fail "Please specify a name for the service"
+  verify_service_name "$SERVICE"
+  SERVICE_ROOT="$PLUGIN_DATA_ROOT/$SERVICE"
+  SERVICE_NAME="$(get_service_name "$SERVICE")"
+  PASSWORD="$(cat "$SERVICE_ROOT/ROOTPASSWORD")"
+  has_tty && SERVICE_TTY_OPTS="-t"
+
+  docker exec -i $SERVICE_TTY_OPTS "$SERVICE_NAME" mongo -u admin -p "$PASSWORD" --authenticationDatabase admin "$SERVICE"
+}
+
+mongo-admin-cmd "$@"