[Node.js] nodemon 실행 시 Internal watch failed: ENOSPC: System limit for number of file watchers reached 오류 해결 방법

● 문제 상황

개발 환경에서는 서버 재기동 없이 변경사항을 바로 적용하기 위해 nodemon을 사용했는데, 실행 시 다음과 같은 오류가 발생했다.

$ npm run dev

> ui-project@1.0.0 dev
> nodemon --watch 'client/**' --exec ts-node server/index.ts

[nodemon] 2.0.15
[nodemon] to restart at any time, enter `rs`
[nodemon] watching path(s): client/**
[nodemon] watching extensions: ts,json
[nodemon] starting `ts-node server/index.ts`
[nodemon] Internal watch failed: ENOSPC: System limit for number of file watchers reached, watch '/data02/npm_test/ui-project/client/ui/myproject/pcweb/trunk/src/img/common/btn.png'

package.json 파일

{
  "name": "ui-project",
  "version": "1.0.0",
  "description": "",
  "main": "dist/index.js",
  "scripts": {
    "start": "node dist/index.js",
    "dev": "nodemon --watch 'client/**' --exec ts-node server/index.ts",
    "build": "tsc"
  },
  "keywords": [],
  "author": "",
  "license": "ISC",
  "dependencies": {
    "bcrypt": "^5.0.1",
    "cookie-parser": "^1.4.5",
    "cors": "^2.8.5",
    "dotenv": "^9.0.2",
    "express": "^4.17.3",
    "serve-index": "^1.9.1",
    "jsonwebtoken": "^8.5.1",
    "mongoose": "^5.12.10",
    "morgan": "^1.10.0",
    "socket.io": "^4.4.1"
  },
  "devDependencies": {
    "@types/bcrypt": "^5.0.0",
    "@types/cookie-parser": "^1.4.2",
    "@types/cors": "^2.8.10",
    "@types/dotenv": "^8.2.0",
    "@types/express": "^4.17.11",
    "@types/serve-index": "^1.9.1",
    "@types/jsonwebtoken": "^8.5.1",
    "@types/mongoose": "^5.10.5",
    "@types/morgan": "^1.9.2",
    "@types/node": "^15.3.1",
    "ts-node-dev": "^1.1.6",
    "typescript": "^4.2.4"
  }
}

tsconfig.json 파일

{
  "compilerOptions": {
    /* Visit https://aka.ms/tsconfig.json to read more about this file */

    /* Basic Options */
    // "incremental": true,                         /* Enable incremental compilation */
    "target": "es6",                                /* Specify ECMAScript target version: 'ES3' (default), 'ES5', 'ES2015', 'ES2016', 'ES2017', 'ES2018', 'ES2019', 'ES2020', or 'ESNEXT'. */
    "module": "commonjs",                           /* Specify module code generation: 'none', 'commonjs', 'amd', 'system', 'umd', 'es2015', 'es2020', or 'ESNext'. */
    // "lib": [],                                   /* Specify library files to be included in the compilation. */
    // "allowJs": true,                             /* Allow javascript files to be compiled. */
    // "checkJs": true,                             /* Report errors in .js files. */
    // "jsx": "preserve",                           /* Specify JSX code generation: 'preserve', 'react-native', 'react', 'react-jsx' or 'react-jsxdev'. */
    // "declaration": true,                         /* Generates corresponding '.d.ts' file. */
    // "declarationMap": true,                      /* Generates a sourcemap for each corresponding '.d.ts' file. */
    // "sourceMap": true,                           /* Generates corresponding '.map' file. */
    // "outFile": "./",                             /* Concatenate and emit output to single file. */
    "outDir": "./dist",                              /* Redirect output structure to the directory. */
    "rootDir": "./server",                             /* Specify the root directory of input files. Use to control the output directory structure with --outDir. */
    // "composite": true,                           /* Enable project compilation */
    // "tsBuildInfoFile": "./",                     /* Specify file to store incremental compilation information */
    // "removeComments": true,                      /* Do not emit comments to output. */
    // "noEmit": true,                              /* Do not emit outputs. */
    // "importHelpers": true,                       /* Import emit helpers from 'tslib'. */
    // "downlevelIteration": true,                  /* Provide full support for iterables in 'for-of', spread, and destructuring when targeting 'ES5' or 'ES3'. */
    // "isolatedModules": true,                     /* Transpile each file as a separate module (similar to 'ts.transpileModule'). */

    /* Strict Type-Checking Options */
    "strict": true,                                 /* Enable all strict type-checking options. */
    // "noImplicitAny": true,                       /* Raise error on expressions and declarations with an implied 'any' type. */
    // "strictNullChecks": true,                    /* Enable strict null checks. */
    // "strictFunctionTypes": true,                 /* Enable strict checking of function types. */
    // "strictBindCallApply": true,                 /* Enable strict 'bind', 'call', and 'apply' methods on functions. */
    // "strictPropertyInitialization": true,        /* Enable strict checking of property initialization in classes. */
    // "noImplicitThis": true,                      /* Raise error on 'this' expressions with an implied 'any' type. */
    // "alwaysStrict": true,                        /* Parse in strict mode and emit "use strict" for each source file. */

    /* Additional Checks */
    // "noUnusedLocals": true,                      /* Report errors on unused locals. */
    // "noUnusedParameters": true,                  /* Report errors on unused parameters. */
    // "noImplicitReturns": true,                   /* Report error when not all code paths in function return a value. */
    // "noFallthroughCasesInSwitch": true,          /* Report errors for fallthrough cases in switch statement. */
    // "noUncheckedIndexedAccess": true,            /* Include 'undefined' in index signature results */
    // "noPropertyAccessFromIndexSignature": true,  /* Require undeclared properties from index signatures to use element accesses. */

    /* Module Resolution Options */
    "moduleResolution": "node",                  /* Specify module resolution strategy: 'node' (Node.js) or 'classic' (TypeScript pre-1.6). */
    // "baseUrl": "./",                             /* Base directory to resolve non-absolute module names. */
    // "paths": {},                                 /* A series of entries which re-map imports to lookup locations relative to the 'baseUrl'. */
    // "rootDirs": [],                              /* List of root folders whose combined content represents the structure of the project at runtime. */
    // "typeRoots": [],                             /* List of folders to include type definitions from. */
    // "types": [],                                 /* Type declaration files to be included in compilation. */
    // "allowSyntheticDefaultImports": true,        /* Allow default imports from modules with no default export. This does not affect code emit, just typechecking. */
    "esModuleInterop": true,                        /* Enables emit interoperability between CommonJS and ES Modules via creation of namespace objects for all imports. Implies 'allowSyntheticDefaultImports'. */
    // "preserveSymlinks": true,                    /* Do not resolve the real path of symlinks. */
    // "allowUmdGlobalAccess": true,                /* Allow accessing UMD globals from modules. */

    /* Source Map Options */
    // "sourceRoot": "",                            /* Specify the location where debugger should locate TypeScript files instead of source locations. */
    // "mapRoot": "",                               /* Specify the location where debugger should locate map files instead of generated locations. */
    // "inlineSourceMap": true,                     /* Emit a single file with source maps instead of having a separate file. */
    // "inlineSources": true,                       /* Emit the source alongside the sourcemaps within a single file; requires '--inlineSourceMap' or '--sourceMap' to be set. */

    /* Experimental Options */
    // "experimentalDecorators": true,              /* Enables experimental support for ES7 decorators. */
    // "emitDecoratorMetadata": true,               /* Enables experimental support for emitting type metadata for decorators. */

    /* Advanced Options */
    "skipLibCheck": true,                           /* Skip type checking of declaration files. */
    "forceConsistentCasingInFileNames": true        /* Disallow inconsistently-cased references to the same file. */
  },
  "include": [
    "server/**/*"
  ]
}

 

● 해결 방법

--watch 옵션에 client/** 이렇게 client 디렉터리 하위의 모든 내용을 넣었는데, 이 안에 들어있는 파일이 많다보니 limit에 걸려서 오류가 발생한 것이었다.

그래서 CentOS 기준으로 다음 명령을 실행해 max_user_watches 값을 수정 적용해주면 된다.

$ echo fs.inotify.max_user_watches=582222 | sudo tee -a /etc/sysctl.conf && sudo sysctl -p
fs.inotify.max_user_watches=582222
net.ipv6.conf.all.disable_ipv6 = 1
vm.swappiness = 0
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
fs.inotify.max_user_watches = 582222

그리고 나서 다시 nodemon을 실행해주면 정상적으로 실행이 되는 것을 볼 수 있다.

$ npm run dev

> ui-project@1.0.0 dev
> nodemon --watch 'client/**' --exec ts-node server/index.ts

[nodemon] 2.0.15
[nodemon] to restart at any time, enter `rs`
[nodemon] watching path(s): client/**
[nodemon] watching extensions: ts,json
[nodemon] starting `ts-node server/index.ts`
Server is running on port 3000
GET / 200 39.895 ms - 10018