Docker 使用 NPM，报了一个错误：

Error: could not get uid/gid

错误详情如下：

Error: could not get uid/gid
[ 'nobody', 0 ]

    at /usr/local/lib/node_modules/npm/node_modules/uid-number/uid-number.js:37:16
    at ChildProcess.exithandler (child_process.js:301:5)
    at ChildProcess.emit (events.js:189:13)
    at maybeClose (internal/child_process.js:978:16)
    at Process.ChildProcess._handle.onexit (internal/child_process.js:265:5)
TypeError: Cannot read property 'get' of undefined
    at errorHandler (/usr/local/lib/node_modules/npm/lib/utils/error-handler.js:205:18)
    at /usr/local/lib/node_modules/npm/bin/npm-cli.js:78:20
    at cb (/usr/local/lib/node_modules/npm/lib/npm.js:228:22)
    at /usr/local/lib/node_modules/npm/lib/npm.js:266:24
    at /usr/local/lib/node_modules/npm/lib/config/core.js:83:7
    at Array.forEach (<anonymous>)
    at /usr/local/lib/node_modules/npm/lib/config/core.js:82:13
    at f (/usr/local/lib/node_modules/npm/node_modules/once/once.js:25:25)
    at afterExtras (/usr/local/lib/node_modules/npm/lib/config/core.js:173:20)
    at Conf.<anonymous> (/usr/local/lib/node_modules/npm/lib/config/core.js:231:22)
/usr/local/lib/node_modules/npm/lib/utils/error-handler.js:205
  if (npm.config.get('json')) {
                 ^

TypeError: Cannot read property 'get' of undefined
    at process.errorHandler (/usr/local/lib/node_modules/npm/lib/utils/error-handler.js:205:18)
    at process.emit (events.js:189:13)
    at process._fatalException (internal/bootstrap/node.js:627:27)

解决方案是在 npm install 之前，执行 npm config set unsafe-perm true 命令。#20861
Dockerfile 文件如下：

FROM node:alpine
WORKDIR /node-app
COPY . /node-app
EXPOSE 8080
# 增加这一行
RUN npm config set unsafe-perm true
RUN npm install
RUN npm install pm2 -g
CMD [ "pm2", "start", "ecosystem.config.js","--no-daemon"]

完。