feat: allow binding service host and port

server.js

@@ -5,8 +5,8 @@ const { createCanvas } = require("canvas");
 const { jsPDF } = require("jspdf");
 const { TextDecoder } = require("util");
 
-const HOST = "127.0.0.1";
-const PORT = 3040;
+const DEFAULT_HOST = "127.0.0.1";
+const DEFAULT_PORT = 3040;
 const PAGE_PADDING_DOTS = 24;
 const DEFAULT_RENDER_OPTIONS = {
   width: 4,
@@ -18,6 +18,22 @@ const DEFAULT_RENDER_OPTIONS = {
 
 let bwipPromise;
 
+function getCliOption(name) {
+  const prefix = `--${name}=`;
+  const option = process.argv.find((argument) => argument.startsWith(prefix));
+
+  return option ? option.slice(prefix.length) : undefined;
+}
+
+function getServerConfig() {
+  const port = Number(getCliOption("port") || process.env.PORT || DEFAULT_PORT);
+
+  return {
+    host: getCliOption("host") || process.env.HOST || DEFAULT_HOST,
+    port: Number.isFinite(port) && port > 0 ? port : DEFAULT_PORT,
+  };
+}
+
 function normalizeZpl(zpl) {
   return zpl.replace(/\\n/g, "\n").replace(/\r\n/g, "\n");
 }
@@ -660,9 +676,10 @@ function buildServer() {
 
 async function start() {
   const app = buildServer();
+  const { host, port } = getServerConfig();
 
   try {
-    await app.listen({ host: HOST, port: PORT });
+    await app.listen({ host, port });
   } catch (error) {
     app.log.error(error);
     process.exit(1);
@@ -676,4 +693,5 @@ if (require.main === module) {
 module.exports = {
   buildServer,
   convertZplToPdf,
+  getServerConfig,
 };