fix: use process.geteuid and catch uid errors in file util

.eslintrc.json

@@ -9,7 +9,20 @@
   "rules": {
     "prefer-spread": "off",
     "prefer-rest-params": "off",
-    "no-useless-constructor": "off"
+    "no-useless-constructor": "off",
+    "no-restricted-properties": [
+      "error",
+      {
+        "object": "process",
+        "property": "geteuid",
+        "message": "process.geteuid() will throw on Windows. Do not use it unless you catch any potential errors."
+      },
+      {
+        "object": "os",
+        "property": "userInfo",
+        "message": "os.userInfo() will throw when there is not an `/etc/passwd` entry for the current user (like when running with --user 12345 in Docker). Do not use it unless you catch any potential errors."
+      }
+    ]
   },
   "settings": {
     "react": {

packages/server/.eslintrc.json

@@ -1,11 +1,8 @@
 {
   "extends": [
-    "plugin:@cypress/dev/tests"
+    "../../.eslintrc.json"
   ],
   "parser": "@typescript-eslint/parser",
-  "env": {
-    "cypress/globals": true
-  },
   "plugins": [
     "cypress"
   ]

packages/server/lib/util/file.js

@@ -13,6 +13,17 @@ const { default: pQueue } = require('p-queue')
 const DEBOUNCE_LIMIT = 1000
 const LOCK_TIMEOUT = 2000
 
+function getUid () {
+  try {
+    // eslint-disable-next-line no-restricted-properties
+    return process.geteuid()
+  } catch (err) {
+    // process.geteuid() can fail, return a constant
+    // @see https://github.com/cypress-io/cypress/issues/17415
+    return 1
+  }
+}
+
 class File {
   constructor (options = {}) {
     if (!options.path) {
@@ -23,7 +34,7 @@ class File {
 
     // If multiple users write to a specific directory is os.tmpdir, permission errors can arise.
     // Instead, we make a user specific directory with os.tmpdir.
-    this._lockFileDir = path.join(os.tmpdir(), `cypress-${os.userInfo().uid}`)
+    this._lockFileDir = path.join(os.tmpdir(), `cypress-${getUid()()}`)
     this._lockFilePath = path.join(this._lockFileDir, `${md5(this.path)}.lock`)
 
     this._queue = new pQueue({ concurrency: 1 })

scripts/run-docker-local.sh

@@ -13,6 +13,7 @@ echo "You should be able to edit files locally"
 echo "but execute the code in the container"
 
 docker run -v $PWD:/home/person/cypress \
+  --user 12345 \
   -w /home/person/cypress${WORKING_DIR:-} \
   -it $name \
   /bin/bash