From 40fa387b5ed12ef2ae4850545ceacad6849c2b00 Mon Sep 17 00:00:00 2001
From: Sebastian Malton <sebastian@malton.name>
Date: Mon, 13 Dec 2021 10:58:24 -0500
Subject: [PATCH] Move all port handling into LensProxy

Signed-off-by: Sebastian Malton <sebastian@malton.name>
---
 src/main/index.ts      | 40 +++++++---------------------------------
 src/main/lens-proxy.ts | 41 +++++++++++++++++++++++++++++++++++------
 2 files changed, 42 insertions(+), 39 deletions(-)

diff --git a/src/main/index.ts b/src/main/index.ts
index c95ae61a54..1c5b80042c 100644
--- a/src/main/index.ts
+++ b/src/main/index.ts
@@ -28,7 +28,7 @@ import * as LensExtensionsCommonApi from "../extensions/common-api";
 import * as LensExtensionsMainApi from "../extensions/main-api";
 import { app, autoUpdater, dialog, powerMonitor } from "electron";
 import { appName, isIntegrationTesting, isMac, isWindows, productName } from "../common/vars";
-import { LensProxy, UnsafePortError } from "./lens-proxy";
+import { LensProxy } from "./lens-proxy";
 import { WindowManager } from "./window-manager";
 import { ClusterManager } from "./cluster-manager";
 import { shellSync } from "./shell-sync";
@@ -184,39 +184,13 @@ app.on("ready", async () => {
 
   initializers.initClusterMetadataDetectors();
 
-  logger.info("🔌 Starting LensProxy");
+  try {
+    logger.info("🔌 Starting LensProxy");
+    await lensProxy.listen();
+  } catch (error) {
+    dialog.showErrorBox("Lens Error", `Could not start proxy: ${error?.message || "unknown error"}`);
 
-  for (let attempt = 0;; attempt += 1) {
-    try {
-      await lensProxy.listen();
-      break;
-    } catch (error) {
-      if (error instanceof UnsafePortError) {
-        lensProxy.close();
-
-        if (attempt < 16) {
-          continue;
-        }
-
-        const result = await dialog.showMessageBox({
-          title: "Lens Error",
-          message: "Tried to start several times but only got ports that chromium considers unsafe. Would you like to continue trying?",
-          buttons: ["No", "Yes"],
-          cancelId: 0,
-          defaultId: 1,
-          type: "error",
-        });
-
-        if (result.response === 1) {
-          attempt = 0;
-          continue;
-        }
-      }
-
-      dialog.showErrorBox("Lens Error", `Could not start proxy: ${error?.message || "unknown error"}`);
-
-      return app.exit();
-    }
+    return app.exit();
   }
 
   // test proxy connection
diff --git a/src/main/lens-proxy.ts b/src/main/lens-proxy.ts
index e5361cdd5a..04160fc729 100644
--- a/src/main/lens-proxy.ts
+++ b/src/main/lens-proxy.ts
@@ -68,7 +68,9 @@ const disallowedPorts = new Set([
   10080,
 ]);
 
-export class UnsafePortError {}
+class UnsafePortError {
+  constructor(public port: number) {}
+}
 
 export class LensProxy extends Singleton {
   protected origin: string;
@@ -111,11 +113,11 @@ export class LensProxy extends Singleton {
   }
 
   /**
-   * Starts the lens proxy.
-   * @resolves After the server is listening
-   * @rejects if there is an error before that happens
+   * Starts to listen on an OS provided port. Will reject if the server throws
+   * an error or if the port picked by the OS is one which chrome rejects
+   * connections to.
    */
-  listen(): Promise<void> {
+  private attemptToListen(): Promise<void> {
     return new Promise<void>((resolve, reject) => {
       this.proxyServer.listen(0, "127.0.0.1");
 
@@ -128,7 +130,7 @@ export class LensProxy extends Singleton {
           if (disallowedPorts.has(port)) {
             logger.warn(`[LENS-PROXY]: Proxy server has with port known to be considered unsafe to connect to by chrome, restarting...`);
 
-            return reject(new UnsafePortError());
+            return reject(new UnsafePortError(port));
           }
 
           logger.info(`[LENS-PROXY]: Proxy server has started at ${address}:${port}`);
@@ -148,6 +150,33 @@ export class LensProxy extends Singleton {
     });
   }
 
+  /**
+   * Starts the lens proxy.
+   * @resolves After the server is listening on a good port
+   * @rejects if there is an error before that happens
+   */
+  async listen(): Promise<void> {
+    const seenPorts = new Set<number>();
+
+    for(;;) {
+      try {
+        this.proxyServer?.close();
+        await this.attemptToListen();
+        break;
+      } catch (error) {
+        if (error instanceof UnsafePortError) {
+          if (seenPorts.has(error.port)) {
+            throw new Error("Failed to start LensProxy due to seeing too many unsafe ports. Please restart Lens.");
+          }
+
+          continue;
+        }
+
+        throw error;
+      }
+    }
+  }
+
   close() {
     logger.info("[LENS-PROXY]: Closing server");
     this.proxyServer.close();