I have a project in Node Js, which executes the project on port 3000 and I access from ngrok with my browser to said localhost port, and it executes a server on port 3001 to make requests to a Maria database db. The project is done in react and the server with express.
I want to save the application logs (errors, warnings, etc.) in a log file so that I can see them whenever I want.
My intention was to use winston, and while I have no problem on the server side (3001), when I try to adapt it to the main project, I get an error that it cannot save files (the reason that appears is that it runs from the browser, and you can't create such a file because you don't have access to the project folders)
Can anyone give me some advice? Am I wrong to use winston, and should I use another?
Greetings and thanks
I've never used winston before and I couldn't find anything online about your error. In the past I've always just used node's fs module to create a log of errors and restarts.
const fs = require('fs')
Node's File System Documentation: https://nodejs.dev/learn/the-nodejs-fs-module
Short YouTube Tutorial: https://www.youtube.com/watch?v=U57kU311-nE
Related
I haven't had any success looking for this because I mostly find misleading questions, about people wanting to use data from a server inside of their electron app. That's not my case.
I have a regular app, which uses a server on the internet, just like any other, but we want to make it available for schools without internet (without any or without reliable internet), so what I'm trying to do is to create a version of my server which runs from an electron exe and serves files for the students conected to the wifi (but no the internet) to access. After the process is done "offline", I will sync the data from the electron app itself.
I tried to run a server from express but I didn't have any progress so far. What I tried was to put the exact same code from my node server in my main.js file and had no luck.
I know that's not what electron is supposed to do, if you're positively sure there is no way to do that, please tell me so I can search for another alternative.
A simple approach is to create a cluster where the master process is the Electron Main and the worker process is the server.
Example:
Change the main on package.json to start.js
On start.js write:
const cluster = require('cluster');
if (cluster.isMaster) {
require('./main.js'); // your electron main file
cluster.fork();
} else {
require('./server.js'); // your server code
}
All the Node.js tutorials that I have followed have put everything in one file. It includes importing of libraries, routing, database connecting and starting of the server, by say, express.js:
var app = require('express');
app.get('/somePath', blah blah);
app.listen(...);
Now, I have 4 node servers behind an Nginx load balancer. It then becomes very difficult to have the source code updated on all the four servers.
Is there a way to keep the source code out of the server creation code in such a way that I can deploy the source code on the servers as one package? The server creation code should not know anything about routing or database connections. It should only be listening to changes in a folder and the moment a new module meta file appears, it starts hosting that web application.
Much like how we deploy a Java code packaged as war by Maven and deployed to the webapp of Tomcat, because Tomcat instantiation is not part of the source code. In node.js it seems server is also part of the source code.
For now, the packaging is not my concern. My concern is how to separate the logic and how do I point all my servers to one source code base?
Node.js or JavaScript for that matter doesn't have a concept like WAR. But what it does have is something similar. To achieve something WAR like, you would essentially bundle the code into one source file using something like webpack. However, this will probably not work with Node.js modules like http (Express uses `http since it likely calls or relies on native V8/C++ functions/libraries.
You could also use Docker and think of the Docker containers as WARs.
Here is what I figured out as a work around:
Keep the servers under a folder say, "server_clusters" and put different node servers there, namely: node1.js, node2.js, node3.js, node4.js, etc (I know, in the real world, the clusters would be different VMs or CPUs altogether but for now, I simply want to separate server creation logic from source code). These files would have this code snippet:
var constants = require('./prop');
var appBasePath = constants.APP_BASE_DIR;
var appFilePath = appBasePath + "/main";
var app = require(appFilePath);
//each server would have just different port number while everything else would remain constant
app.listen(8080, function (req, res) {
console.log("server started up");
});
Create a properties file that would have the path to the source code and export the object. That simple. This is what is used on line#1 in the above code
Create the source directory project wherever you want on the machine and just update its home directory in the constant file above. The source code directory can export one landing file that will provide the express app to the servers to start:
var express = require('express');
var app = express();
module.exports = app;
With this, there are multiple servers that are pointing to the same source code.
Hope this helps to those who are facing the same problem.
Other approaches are welcome.
I am currently developing a MEAN Stack application.
Previously my node version is 0.12 and I was using grunt to run my application which uses nodemon (which uses server.js) to run the server and watch to monitor for changes.
it works fine all the way till i upgrade my node to v 0.4.
now when I use grunt, the console.log does not print to console at all and it only works if i use
node server.js
instead of
grunt
the image below shows the situation that i'm facing:
in an ideal situation, when running grunt, I should be able to see the message
App listening on port 8000
however after updating node, the console.log doesn't seem to be working for my grunt(?)/nodemon(?) anymore.
can anyone advise on this matter?
thank you.
You can use very useful logging module winston. Using this you can log all your errors in a text file with timestamp, Which will be very helpful for application support. You can use it's debug, error, info methods for the corresponding console.debug(), console.error(), console.info().
EX:
Var logger = require('winston')
logger.debug('Debug things here');
logger.info('put info to track');
logger.error('to track error with status code')
I want to create an upload form that will send an image to my hosted server, but i can't find a clear answer on how node.js interacts with the clients side of things.
A lot of the file upload examples I can find use a simple fs get from the temp directory. But when I run code on my server that looks like this:
var os = require('os');
var ostemp = os.tmpDir();
console.log( "Temp directory", ostemp );
It obviously returns a server filepath to the logs when I visit, not my windows temp. Makes sense as node.js is purely server side, so how is it usually done?
EDIT:
I think a related problem I'm having is that my host (GANDI) only allows SFTP file transfer, which might be preventing me from sending files via a form submit thing, though I might be confused about that too. Either way I'd appreciate being set straight...
this is my first node.js and socket.io application , i didn't use express ,I want to deploy the application on heroku do i need to use it ? i mean i just did npm install socket.io on localhost and in my server file i.e game.js i have io = require("socket.io") and socket = io.listen(Number(process.env.PORT)) only and in one of the files where from where i am sending the message i have socket = io.connect();
so please tell me if i need to use express and how show i modify my existing application ?
I have given the link to the source of application
( https://github.com/bitgeeky/herokutest )
Although the Application works fine on localhost by changing the port no , to some port no like (8000) but Heroku error log on doing "heroku open" is http://pastebin.com/MtB0z5vQ
I noticed that you haven't created a http server. I am assuming that you are creating a web application, since you are deploying to heroku. For that, you need to create a http server in nodejs.
Go through socket.io https://github.com/LearnBoost/socket.io
Also http://socket.io/#how-to-use
This should get you started
Note: You do not need express. But it will make your work easier in many ways. Depends on the type of application that you want to create.