将 mock 数据托管到本地，建立主备数据请求方案

app.js

@@ -2,6 +2,17 @@ const express = require('express')
 const ejs = require('ejs')
 const path = require('path')
 const axios = require('axios')
+const fs = require('fs')
+
+const PORT = 3001 //设置 express 服务器端口
+
+/**
+ * 修改 axios 请求资源 baseUrl
+ * 请求本地资源时，如果不设置，将请求 80 端口
+ * 请求远程资源（包含完整的主机、端口、协议的资源路径）不会遇到这个问题
+ * 此处设置端口和 express 服务器端口一致
+ */
+axios.defaults.baseURL = 'http://localhost:' + PORT 
 
 const app = express()
 
@@ -14,42 +25,68 @@ app.set('view engine', 'ejs');
  * Home Page & Post List Page
  */
 app.get('/', async (req, res) => {
-  const response = await axios.get('https://raw.githubusercontent.com/getgridea/mock-json/master/list.json')
+  const response = await requestMockData('https://raw.githubusercontent.com/getgridea/mock-json/master/list.json')
   res.render('index', { ...response.data })
 })
 
 /**
  * Post Page
  */
 app.get('/post/:postName', async (req, res) => {
-  const response = await axios.get('https://raw.githubusercontent.com/getgridea/mock-json/master/post.json')
+  const response = await requestMockData('https://raw.githubusercontent.com/getgridea/mock-json/master/post.json')
   res.render('post', { ...response.data })
 })
 
 /**
  * Archives Page
  */
 app.get('/archives', async (req, res) => {
-  const response = await axios.get('https://raw.githubusercontent.com/getgridea/mock-json/master/archives.json')
+  const response = await requestMockData('https://raw.githubusercontent.com/getgridea/mock-json/master/archives.json')
   res.render('archives', { ...response.data })
 })
 
 /**
  * tags Page
  */
 app.get('/tags', async (req, res) => {
-  const response = await axios.get('https://raw.githubusercontent.com/getgridea/mock-json/master/tags.json')
+  const response = await requestMockData('https://raw.githubusercontent.com/getgridea/mock-json/master/tags.json')
   res.render('tags', { ...response.data })
 })
 
 /**
  * tag Page
  */
 app.get('/tag/:tagName', async (req, res) => {
-  const response = await axios.get('https://raw.githubusercontent.com/getgridea/mock-json/master/tag.json')
+  const response = await requestMockData('https://raw.githubusercontent.com/getgridea/mock-json/master/tag.json')
   res.render('tag', { ...response.data })
 })
 
-//使用8080端口
-app.listen(3001)
-console.log("The server is running on 3001")
+/**
+ * 请求 mock 数据
+ */
+app.get('/mock/:path', async (req, res) => {
+  const path = req.params.path;
+  fs.readFile(path.join(__dirname, 'mock', path), (err, json) => {
+    if (err) {
+      res.status(404).send(err);
+      return;
+    }
+    res.set('Content-Type', 'application/json').status(200).send(json);
+  })
+})
+
+//使用 PORT 端口
+app.listen(PORT)
+console.log("The server is running on " + PORT)
+
+/**
+ * 请求 mock 主备数据
+ */
+function requestMockData(url) {
+  const backupUrl = '/mock/' + url.split('/').pop()
+  return axios.get(url)
+    .then(result => result)
+    .catch(reason => console.log(`[Main][${url}]\n${reason.message}`))
+    .then(() => axios.get(backupUrl))
+    .catch(reason => console.log(`[Backup][${url}]\n${reason.message}`))
+}