search-articles.js

const AWS = require('aws-sdk');
const path = require ('path');
const https = require ('https');

exports.handler = (event, context, callback) => {
    const { query, endpoint, index, doctype } = event;
    const size = 10;
    const from = parseInt(event.from) || 0;
    if (!query || !endpoint || !index || !doctype) {
        callback(new Error('Missing required parameters'), event);
        return;
    }
    
    function getESResult(method, apiPath, body, callback) {
        const creds = new AWS.EnvironmentCredentials('AWS');
        const esEndpoint = new AWS.Endpoint(endpoint);
        const req = new AWS.HttpRequest(esEndpoint);
        req.method =method;
        req.path = path.join('/', index, doctype, apiPath);
        console.log(req.path);
        req.region = 'ap-northeast-1';
        if (body) {
            req.body = JSON.stringify(body);
        }
        req.headers['presigned-expires'] = false;
        req.headers['Host'] = esEndpoint.host;
        
        const signer = new AWS.Signers.V4(req, 'es');
        signer.addAuthorization(creds, new Date());
        const send = new AWS.NodeHttpClient();
        send.handleRequest(req, null, (httpResp) => {
            let body = '';
            httpResp.on('data', (chunk) => {
                body += chunk || '';
            });
            httpResp.on('end', (chunk) => {
                body += chunk || '';
                console.log(body);
                try {
                    const data = JSON.parse(body);
                    callback(null, data);
                } catch(e) {
                    console.log(e);
                    callback(e, null);
                }
            });
        }, (err) => {
            callback(err, null);
        });
    }
    
    getESResult('POST', '_search', {
          from, size,
          query: {
            match: {
              body: query
            }
          }
        }, (e, data) => {
            const { hits, total } = data.hits;
            let next = from + size;
            if (next > total) {
              next = null;
            }
            const articles = hits.map((hit) => {
              return Object.assign({ id: hit._id }, hit._source)
            });
            callback(null, { total, next, articles });
        });
};

similar-articles.js

const AWS = require('aws-sdk');
const path = require ('path');
const https = require ('https');

exports.handler = (event, context, callback) => {
    console.log(event);
    const { id, endpoint, index, doctype } = event;
    const size = 10;
    if (!id || !endpoint || !index || !doctype) {
        callback(new Error('Missing required parameters' + id + endpoint + index + doctype), event);
        return;
    }
    
    function getESResult(method, apiPath, body, callback) {
        const creds = new AWS.EnvironmentCredentials('AWS');
        const esEndpoint = new AWS.Endpoint(endpoint);
        const req = new AWS.HttpRequest(esEndpoint);
        req.method =method;
        req.path = path.join('/', index, doctype, apiPath);
        console.log(req.path);
        req.region = 'ap-northeast-1';
        if (body) {
            req.body = JSON.stringify(body);
        }
        req.headers['presigned-expires'] = false;
        req.headers['Host'] = esEndpoint.host;
        
        const signer = new AWS.Signers.V4(req, 'es');
        signer.addAuthorization(creds, new Date());
        const send = new AWS.NodeHttpClient();
        send.handleRequest(req, null, (httpResp) => {
            let body = '';
            httpResp.on('data', (chunk) => {
                body += chunk || '';
            });
            httpResp.on('end', (chunk) => {
                body += chunk || '';
                console.log(body);
                try {
                    const data = JSON.parse(body);
                    callback(null, data);
                } catch(e) {
                    console.log(e);
                    callback(e, null);
                }
            });
        }, (err) => {
            callback(err, null);
        });
    }

    getESResult('GET', encodeURIComponent(id), null, (e, data) => {
        if (e) {
            callback(e, null);
            return;
        }
        const { body, title } = data._source || {};
        getESResult('POST', '_search', {
              from: 0, size,
              query: {
                more_like_this: {
                  fields: ['title', 'tags', 'body'],
                  like: title + ' ' + body
                }
              }
            }, (e, data) => {
                const { hits } = data.hits;
                const articles = hits.map((hit) => {
                  return Object.assign({ id: hit._id }, hit._source)
                });
                callback(null, { articles });
            });
    });
};