✨ Add support for pinging IPv6 addresses and hostnames

src/update.ts

@@ -1,3 +1,6 @@
+import dns from "node:dns";
+import { isIP, isIPv6 } from "node:net";
+
 import slugify from "@sindresorhus/slugify";
 import dayjs from "dayjs";
 import { mkdirp, readFile, writeFile } from "fs-extra";
@@ -152,8 +155,24 @@ export const update = async (shouldCommit = false) => {
         console.log("Using tcp-ping instead of curl");
         try {
           let status: "up" | "down" | "degraded" = "up";
+          // https://github.com/upptime/upptime/discussions/888
+          const url = replaceEnvironmentVariables(site.url),
+          let address;
+          if (isIP(url)) {
+            if (site.ipv6 && !isIPv6(url))
+              throw Error('Site URL must be IPv6 for ipv6 check');
+            address = url;
+          } else {
+            if (site.ipv6)
+              address = (await dns.promises.resolve6(url))[0];
+            else
+              address = (await dns.promises.resolve4(url))[0];
+            if (!isIP(address))
+              throw Error('Site IP address could not be resolved');
+          }
+
           const tcpResult = await ping({
-            address: replaceEnvironmentVariables(site.url),
+            address,
             attempts: 5,
             port: Number(replaceEnvironmentVariables(site.port ? String(site.port) : "")),
           });