ci: enable VNC over ssh

.circleci/config.yml

@@ -88,6 +88,12 @@ aliases:
         git checkout -B "$CIRCLE_BRANCH" "$CIRCLE_SHA1"
       fi
 
+      # Piggyback on this alias to enable VNC connections
+      # The if statement will only be true on node-browsers executors
+      if [ "${SHELL}" != "/bin/bash" ]; then
+        cp ~/project/.circleci/scripts/enable-vnc.sh ~/.bashrc
+      fi
+
   # Check if MMI Optional tests should run
   - &check-mmi-optional
     name: Check if MMI Optional tests should run

.circleci/scripts/enable-vnc.sh

@@ -0,0 +1,21 @@
+#!/usr/bin/env bash
+
+# This script is based on the documentation from CircleCI, which does not work as written
+# https://circleci.com/docs/browser-testing/#interacting-with-the-browser-over-vnc
+
+set -e
+set -u
+set -o pipefail
+
+cd ~/project
+
+if [ ! -f installed.lock ]; then
+  touch installed.lock
+
+  sudo apt update
+  sudo apt install -y fluxbox tigervnc-standalone-server
+
+  export DISPLAY=:1
+  tigervncserver -SecurityTypes none -desktop fluxbox
+  fbsetbg -c app/images/icon-512.png
+fi

docs/ssh-to-circleci.md

@@ -0,0 +1,28 @@
+# Debugging E2E tests by connecting to CircleCI over SSH and VNC
+
+Developers often say "I can't reproduce this CI failure locally, but it fails on CircleCI."
+
+If you find yourself in that situation, one option is to use Codespaces, which can reproduce some of these failures, and is a little bit easier to use.
+
+The other NEW option is to SSH into CircleCI and use VNC.
+
+1. You must be logged into CircleCI and have access to metamask-extension
+2. "Rerun job with SSH" [Documentation](https://circleci.com/docs/ssh-access-jobs/)
+3. Look for this instruction
+
+   ```
+   You can now SSH into this box if your SSH public key is added:
+       $ ssh -p xxxxx xxx.xxx.xxx.xxx
+   ```
+
+4. Copy the command that CircleCI gives you and add `-L 5902:localhost:5901` (this will tunnel the VNC connection over SSH)
+5. When you login to SSH, it automatically executes `/.circleci/scripts/enable-vnc.sh` to set up the connection
+6. Use your favorite VNC viewer on your local machine to connect to `localhost:5902`
+   - Mac: Finder menu > GO > Connect to server (or <Cmd> + K), then use `vnc://localhost:5902`
+   - Linux: `tigervnc-viewer` is a good package to match the server
+   - Windows: [RealVNC Viewer](https://www.realvnc.com/en/connect/download/viewer/windows/) or [TightVNC](https://www.tightvnc.com/download.php)
+7. Run your E2E tests as usual and watch the browser open in VNC
+
+_Warning: be careful with parallelism. If you run "Rerun job with SSH" on a job that has `parallelism: 24`, it will rerun all 24 VMs with SSH._
+
+_Note: this procedure was based on the documentation from CircleCI, which does not work as written https://circleci.com/docs/browser-testing/#interacting-with-the-browser-over-vnc_