Fix codespace url (#3436)

* Fix codespace url (https://github.com/louislam/uptime-kuma/pull/3432#discussion_r1265120809)

.devcontainer/devcontainer.json

@@ -1,5 +1,5 @@
 {
-    "image": "mcr.microsoft.com/devcontainers/javascript-node:dev-20-bookworm",
+    "image": "mcr.microsoft.com/devcontainers/javascript-node:dev-18-bookworm",
     "features": {
         "ghcr.io/devcontainers/features/github-cli:1": {}
     },
@@ -14,8 +14,7 @@
         "vscode": {
             "extensions": [
                 "streetsidesoftware.code-spell-checker",
-                "dbaeumer.vscode-eslint",
-                "GitHub.copilot"
+                "dbaeumer.vscode-eslint"
             ]
         }
     },

config/vite.config.js

@@ -17,7 +17,9 @@ export default defineConfig({
     },
     define: {
         "FRONTEND_VERSION": JSON.stringify(process.env.npm_package_version),
-        "DEVCONTAINER": process.env.DEVCONTAINER,
+        "DEVCONTAINER": JSON.stringify(process.env.DEVCONTAINER),
+        "GITHUB_CODESPACES_PORT_FORWARDING_DOMAIN": JSON.stringify(process.env.GITHUB_CODESPACES_PORT_FORWARDING_DOMAIN),
+        "CODESPACE_NAME": JSON.stringify(process.env.CODESPACE_NAME),
     },
     plugins: [
         commonjs(),

src/util-frontend.js

@@ -83,12 +83,19 @@ export function getResBaseURL() {
 
 export function isDevContainer() {
     // eslint-disable-next-line no-undef
-    return (typeof DEVCONTAINER === "number" && DEVCONTAINER === 1);
+    return (typeof DEVCONTAINER === "string" && DEVCONTAINER === "1");
 }
 
+/**
+ * Supports GitHub Codespaces only currently
+ */
 export function getDevContainerServerHostname() {
-    // replace -3000 with -3001
-    return location.hostname.replace(/-3000\.preview\.app\.github\.dev/, "-3001.preview.app.github.dev");
+    if (!isDevContainer()) {
+        return "";
+    }
+
+    // eslint-disable-next-line no-undef
+    return CODESPACE_NAME + "-3001." + GITHUB_CODESPACES_PORT_FORWARDING_DOMAIN;
 }
 
 /**