feat(admin,admin-ui,medusa): Add Medusa Admin plugin (#3334)

packages/admin/src/api/index.ts

@@ -0,0 +1,78 @@
+import express, { Request, Response, Router } from "express"
+import fse from "fs-extra"
+import { ServerResponse } from "http"
+import { resolve } from "path"
+import colors from "picocolors"
+import { PluginOptions } from "../types"
+import { reporter } from "../utils"
+
+export default function (_rootDirectory: string, options: PluginOptions) {
+  const app = Router()
+
+  const { serve = true, path = "app", outDir } = options
+
+  if (serve) {
+    let buildPath: string
+    let htmlPath: string
+
+    if (outDir) {
+      buildPath = resolve(process.cwd(), outDir)
+      htmlPath = resolve(buildPath, "index.html")
+    } else {
+      buildPath = resolve(
+        require.resolve("@medusajs/admin-ui"),
+        "..",
+        "..",
+        "build"
+      )
+      htmlPath = resolve(buildPath, "index.html")
+    }
+
+    /**
+     * The admin UI should always be built at this point, but in the
+     * rare case that another plugin terminated a previous startup, the admin
+     * may not have been built correctly. Here we check if the admin UI
+     * build files exist, and if not, we throw an error, providing the
+     * user with instructions on how to fix their build.
+     */
+    try {
+      fse.ensureFileSync(htmlPath)
+    } catch (_err) {
+      reporter.panic(
+        new Error(
+          `Could not find the admin UI build files. Please run ${colors.bold(
+            "`medusa-admin build`"
+          )} to build the admin UI.`
+        )
+      )
+    }
+
+    const html = fse.readFileSync(htmlPath, "utf-8")
+
+    const sendHtml = (_req: Request, res: Response) => {
+      res.setHeader("Cache-Control", "no-cache")
+      res.setHeader("Vary", "Origin, Cache-Control")
+      res.send(html)
+    }
+
+    const setStaticHeaders = (res: ServerResponse) => {
+      res.setHeader("Cache-Control", "max-age=31536000, immutable")
+      res.setHeader("Vary", "Origin, Cache-Control")
+    }
+
+    app.get(`/${path}`, sendHtml)
+    app.use(
+      `/${path}`,
+      express.static(buildPath, {
+        setHeaders: setStaticHeaders,
+      })
+    )
+    app.get(`/${path}/*`, sendHtml)
+  } else {
+    app.get(`/${path}`, (_req, res) => {
+      res.send("Admin not enabled")
+    })
+  }
+
+  return app
+}