Use Winston for logging

ch10/docker-images/web-ping/Dockerfile

@@ -1,10 +1,17 @@
+FROM node:12.17 AS builder
+
+WORKDIR /src
+COPY src/package.json .
+RUN npm install
+
 FROM node:12.17-alpine3.11
 
-CMD ["node", "/web-ping/app.js"]
+CMD ["node", "/app/app.js"]
 
 ENV TARGET="blog.sixeyed.com" \
     METHOD="HEAD" \
     INTERVAL="3000"
 
-WORKDIR /web-ping
-COPY app.js .
+WORKDIR /app
+COPY --from=builder /src/node_modules/ /app/node_modules/
+COPY src/ .

ch10/docker-images/web-ping/app.js → ch10/docker-images/web-ping/src/app.js

@@ -1,21 +1,22 @@
 const https = require('https');
+const log = require("./log");
 
 const options = {
     hostname: process.env.TARGET,
     method: process.env.METHOD
   };
 
-console.log('** web-ping ** Pinging: %s; method: %s; %dms intervals', options.hostname, options.method, process.env.INTERVAL);
+log.Logger.info('** web-ping ** Pinging: %s; method: %s; %dms intervals', options.hostname, options.method, process.env.INTERVAL);
 
 let i = 1;
 let start = new Date().getTime();
 setInterval(() => {    
     start = new Date().getTime();
-    console.log('Making request number: %d; at %d', i++, start);
+    log.Logger.debug('Making request number: %d; at %d', i++, start);
     var req = https.request(options, (res) => {
         var end = new Date().getTime();    
         var duration = end-start;    
-        console.log('Got response status: %s at %d; duration: %dms', res.statusCode, end, duration);
+        log.Logger.debug('Got response status: %s at %d; duration: %dms', res.statusCode, end, duration);
     });
     req.on('error', (e) => {
         console.error(e);

ch10/docker-images/web-ping/src/config/logConfig.js

@@ -0,0 +1,16 @@
+const { format, transports } = require('winston');
+var logConfig = module.exports = {};
+
+logConfig.options = {
+    transports: [
+        new transports.Console({
+            level: 'debug',
+            format: format.combine(
+                format.splat(),
+                format.printf(log => {
+                    return `${log.message}`
+                })
+            )
+        })
+    ]
+};

ch10/docker-images/web-ping/src/log.js

@@ -0,0 +1,5 @@
+const winston = require('winston');
+var logConfig = require('./config/logConfig');
+
+const logger = winston.createLogger(logConfig.options);
+exports.Logger = logger;

ch10/docker-images/web-ping/src/package.json

@@ -0,0 +1,9 @@
+{
+  "name": "web-ping",
+  "version": "1.0.0",
+  "main": "app.js",
+  "author": "kiamol",
+  "dependencies": {
+    "winston": "3.3.3"
+  }
+}