8ud2H9fB

1const express = require('express')
2const responseTime = require('response-time')
3const axios = require('axios')
4const redis = require('redis')
5const AWS = require('aws-sdk')
6
7const bucketName = 'andreasgarvik-wikipedia-store'
8
9const apiVersion = { apiVersion: '2006-03-01' }
10
11;(async () => {
12	try {
13		await new AWS.S3(apiVersion).createBucket({ Bucket: bucketName }).promise()
14		console.log('Successfully created ' + bucketName)
15	} catch (e) {
16		console.error('Could not connect to S3')
17	}
18})()
19
20const app = express()
21app.use(responseTime())
22
23const redisClient = redis.createClient()
24redisClient.on('error', err => {
25	console.log('Error ' + err)
26})
27
28app.get('/api/search', (req, res) => {
29	const query = req.query.query.trim()
30	const searchUrl = `https://en.wikipedia.org/w/api.php?action=parse&format=json&section=0&page=${query}`
31	const redisKey = `wikipedia:${query}`
32	const s3Key = `wikipedia-${query}`
33
34	redisClient.get(redisKey, async (err, result) => {
35		if (result) {
36			res.status(200).json({ source: 'Redis Cache', ...JSON.parse(result) })
37		} else {
38			new AWS.S3(apiVersion).getObject(
39				{ Bucket: bucketName, Key: s3Key },
40				async (err, result) => {
41					if (result) {
42						res
43							.status(200)
44							.json({ source: 'S3 Bucket', ...JSON.parse(result.Body) })
45					} else {
46						response = await getWiki(searchUrl)
47						await setS3(s3Key, response)
48						redisClient.setex(
49							redisKey,
50							3600,
51							JSON.stringify({ source: 'Redis Cache', ...response }),
52							() => console.log('Successfully stored data in redis')
53						)
54						res.status(200).json({ source: 'Wikipedia API', ...response })
55					}
56				}
57			)
58		}
59	})
60})
61
62const setS3 = async (s3Key, responseJSON) => {
63	const body = JSON.stringify({
64		source: 'S3 Bucket',
65		...responseJSON
66	})
67	const objectParams = {
68		Bucket: bucketName,
69		Key: s3Key,
70		Body: body
71	}
72	await new AWS.S3(apiVersion).putObject(objectParams).promise()
73	console.log('Successfully uploaded data to ' + bucketName + '/' + s3Key)
74}
75
76const getWiki = async searchUrl => {
77	const response = await axios.get(searchUrl)
78	return response.data
79}
80
81app.get('/api/store', (req, res) => {
82	const key = req.query.key.trim()
83
84	// Construct the wiki URL and S3 key
85	const searchUrl = `https://en.wikipedia.org/w/api.php?action=parse&format=json&section=0&page=${key}`
86	const s3Key = `wikipedia-${key}`
87	const params = { Bucket: bucketName, Key: s3Key }
88
89	return new AWS.S3(apiVersion).getObject(params, (err, result) => {
90		if (result) {
91			// Serve from S3
92			console.log(result)
93			const resultJSON = JSON.parse(result.Body)
94			return res.status(200).json(resultJSON)
95		} else {
96			// Serve from Wikipedia API and store in S3
97			return axios
98				.get(searchUrl)
99				.then(response => {
100					const responseJSON = response.data
101					const body = JSON.stringify({
102						source: 'S3 Bucket',
103						...responseJSON
104					})
105					const objectParams = { Bucket: bucketName, Key: s3Key, Body: body }
106					const uploadPromise = new AWS.S3(apiVersion)
107						.putObject(objectParams)
108						.promise()
109
110					uploadPromise.then(function(data) {
111						console.log(
112							'Successfully uploaded data to ' + bucketName + '/' + s3Key
113						)
114					})
115					return res
116						.status(200)
117						.json({ source: 'Wikipedia API', ...responseJSON })
118				})
119				.catch(err => {
120					return res.json(err)
121				})
122		}
123	})
124})
125
126app.listen(3000, () => {
127	console.log('Server listening on port: 3000')
128})