依赖：cookieparser、@nuxtjs/axios

在 plugins/axios.js 中设置请求头：

import { Message } from 'element-ui'
const cookieparser = process.server ? require('cookieparser') : undefined

// eslint-disable-next-line prettier/prettier
export default function (ctx) {
  ctx.$axios.onRequest((config) => {
    // 客户端设置token
    if (process.client) {
      if (ctx.store.state.auth) {
        config.headers.Authorization = 'bearer ' + ctx.store.state.auth.access_token
        config.headers.token = ctx.store.state.auth.access_token
      }
    }
    // 服务端设置token
    if (process.server) {
      if (ctx.req.headers.cookie) {
        const parsed = cookieparser.parse(ctx.req.headers.cookie)
        try {
          const auth = JSON.parse(parsed.auth)
          config.headers.Authorization = 'bearer ' + auth.access_token
          config.headers.token = auth.access_token
        } catch (err) {
          // 找不到有效的Cookie
        }
      }
    }
    // 开发模式打印 URL
    if (process.env.NODE_ENV !== 'production') {
      console.log('Making request to ' + config.url)
      // console.log('Making request to ', config)
    }
  })

  ctx.$axios.onResponse((res) => {
    // console.log('onResponse ', res)
    const code = res.data.code || null
    const msg = res.data.msg || ''
    if (code) {
      if (code !== 0) {
        Message.error(msg)
        return Promise.reject(msg)
      }
    }
  })

  ctx.$axios.onError((error) => {
    const code = parseInt(error.response && error.response.status)
    if (code === 400) {
      ctx.redirect('/400')
    }
  })
}

然后在 store 的 actions 中的 nuxtServerInit 中通过req的cookie设置store，将token保存在store中

const cookieparser = process.server ? require('cookieparser') : undefined
export const state = () => ({
  auth: null
})

export const mutations = {
  setAuth(state, auth) {
    // console.log(auth)
    state.auth = auth
  }
}
export const actions = {
  nuxtServerInit({ commit }, { req }) {
    let auth = null
    if (req.headers.cookie) {
      const parsed = cookieparser.parse(req.headers.cookie)
      try {
        auth = JSON.parse(parsed.auth)
      } catch (err) {
        // 找不到有效的Cookie
      }
    }
    commit('setAuth', auth)
  }