feat: implement exists and linked subcommands

subcommands/exists

@@ -0,0 +1,20 @@
+#!/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-exists-cmd() {
+  #E here we check if the lolipop $PLUGIN_COMMAND_PREFIX service exists.
+  #E dokku $PLUGIN_COMMAND_PREFIX:exists lolipop
+  #A service, service to run command against
+  declare desc="check if the $PLUGIN_SERVICE service exists"
+  local cmd="$PLUGIN_COMMAND_PREFIX:exists" 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"
+  dokku_log_info1 "Service $SERVICE exists"
+}
+
+service-exists-cmd "$@"