CircleCI配置初始化阶段如何指定使用Node.js 12版本

方案1：使用已有Node orb直接指定版本 #

你已经引入了官方的circleci/node orb，不需要手动安装nvm切换版本，直接给node/install步骤传入version参数即可指定安装的Node版本，只需给原有配置加一行参数，同时删掉冗余的nvm相关操作步骤即可，修改后的完整配置如下：

version: 2.1
orbs:
  node: circleci/node@4.1.0
  aws-cli: circleci/aws-cli@2.0.3
  eb: circleci/aws-elastic-beanstalk@2.0.1
jobs:
  build:
    docker:
      - image: "cimg/base:stable"
    steps:
      - node/install:
          version: '12'
      - checkout
      - aws-cli/setup
      - eb/setup
      - run:
          name: Check current version of node
          command: node -v
      - run:
          name: Back-End Install
          command: |
            npm run backend:install
      - run:
          name: Front-End Install
          command: |
            npm run frontend:install
      - run:
          name: Back-End Build
          command: |
            npm run backend:build
      - run:
          name: Front-End Build
          command: |
            npm run frontend:build
      - run:
          name: Back-End Deploy
          command: |
            npm run backend:deploy
      - run:
          name: Front-End Deploy
          command: |
            npm run frontend:deploy

方案2：直接使用预装Node 12的官方Docker镜像 #

可以直接把你当前用的cimg/base:stable镜像换成对应Node版本的cimg/node:12镜像，连node/install步骤都可以完全省略，环境初始化速度更快，精简后的配置如下：

version: 2.1
orbs:
  aws-cli: circleci/aws-cli@2.0.3
  eb: circleci/aws-elastic-beanstalk@2.0.1
jobs:
  build:
    docker:
      - image: "cimg/node:12"
    steps:
      - checkout
      - aws-cli/setup
      - eb/setup
      - run:
          name: Check current version of node
          command: node -v
      - run:
          name: Back-End Install
          command: |
            npm run backend:install
      - run:
          name: Front-End Install
          command: |
            npm run frontend:install
      - run:
          name: Back-End Build
          command: |
            npm run backend:build
      - run:
          name: Front-End Build
          command: |
            npm run frontend:build
      - run:
          name: Back-End Deploy
          command: |
            npm run backend:deploy
      - run:
          name: Front-End Deploy
          command: |
            npm run frontend:deploy

内容的提问来源于stack exchange，提问作者Arefe