feat: add service:links command

This allows users to script against apps that are linked to a given service

subcommands/links

@@ -0,0 +1,24 @@
+#!/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"
+
+service-links-cmd() {
+  #E list all apps linked to the 'lolipop' $PLUGIN_COMMAND_PREFIX service.
+  #E dokku $PLUGIN_COMMAND_PREFIX:links lolipop
+  #A service, service to run command against
+  declare desc="list all apps linked to the $PLUGIN_SERVICE service"
+  local cmd="$PLUGIN_COMMAND_PREFIX:links" argv=("$@")
+  [[ ${argv[0]} == "$cmd" ]] && shift 1
+  declare SERVICE="$1"
+  local SERVICE_ROOT="$PLUGIN_DATA_ROOT/$SERVICE"
+  local LINKS_FILE="$SERVICE_ROOT/LINKS"
+
+  [[ -z "$SERVICE" ]] && dokku_log_fail "Please specify a valid name for the service"
+  verify_service_name "$SERVICE"
+  service_links "$SERVICE"
+}
+
+service-links-cmd "$@"