ping | A minimalistic game in 256 bytes of HTML and JS

I'm trying to write a discord bot.

Now there is one command in which another user is selected. So far, all commands work except for one, checking for the existence of a user.

That's how I do it:

I use MacOS 10.14.6 and few days ago I faced with a problem on my computer with localhost. Rubymine can't connect to database with an error "java.net.NoRouteToHostException: Can't assign requested address (Address not available).". Also when I run puma server on 0.0.0.0:3000, browser can't open page on this address, and when I run server on 127.0.0.1:3000, browser can't open page on this address too, but can open on localhost:3000. I ran ping and got this output:

I am working on a simple web app for learning purposes using Angular for the frontend and Java Spring for the backend. I don't have a particular problem that I want you guys to help me out with, instead I have a question about OAuth2 authentication.

I have registered my Angular SPA in Azure AD (Authorization Code Flow + PKCE), I set up roles and everything is working okay. My question is what do I do when authenticated users ping my backend? My backend has no information about the users.

I thought of a solution to make a web filter, and every time an authenticated user pings any endpoint requiring the user to be authenticated, to check the database if the user exists (through the username), and save him if he does not exist. I'm pretty sure this will work, but I don't think this is the best solution, considering my web filter will have to read from the databases for every single HTTP request that comes in, and write to the database occasionally (if the user logs in for the first time).

I shouldn't be worried about performance issues because I'm building this strictly for learning purposes, but nevertheless I want to do this the right way. I tried googling this in multiple ways, but I guess I'm not using the right keywords to find what I'm looking for. Any opinion or advice would be much appreciated! Thanks!

EDIT: I followed this article to achieve the OAuth2 + OIDC authentication and authorization, my security config in the backend is the same: https://ordina-jworks.github.io/security/2020/08/18/Securing-Applications-Azure-AD.html

Whenever I am trying to run the docker images, it is exiting in immediately.

I am working on a "heartbeat" application that pings hundreds of IP addresses every minute via a loop. The IP addresses are stored in a list of a class Machines. I have a loop that creates a Task (where MachinePingResults is basically a Tuple of an IP and online status) for each IP and calls a ping function using System.Net.NetworkInformation.

The issue I'm having is that after hours (or days) of running, one of the loops of the main program fails to finish the Tasks which is leading to a memory leak. I cannot determine why my Tasks are not finishing (if I look in the Task list during runtime after a few days of running, there are hundreds of tasks that appear as "awaiting"). Most of the time all the tasks finish and are disposed; it is just randomly that they don't finish. For example, the past 24 hours had one issue at about 12 hours in with 148 awaiting tasks that never finished. Due to the nature of not being able to see why the Ping is hanging (since it's internal to .NET), I haven't been able to replicate the issue to debug.

(It appears that the Ping call in .NET can hang and the built-in timeout fail if there is a DNS issue, which is why I built an additional timeout in)

I have a way to cancel the main loop if the pings don't return within 15 seconds using Task.Delay and a CancellationToken. Then in each Ping function I have a Delay in case the Ping call itself hangs that forces the function to complete. Also note I am only pinging IPv4; there is no IPv6 or URL.

Main Loop

I have two containers App and Webserver. Webserver is plain nginx:alpine image and App is expressjs app running on port 3030 under ubuntu:focal. I heard that this is a common practise to use separate containers for application and server. So I added proxy_pass http://app:3030/; to nginx config. Something went wrong and I digged into this a bit. To exclude incorrect nginx setup I checked raw curl requests from webserver to app container with no luck. Here is my docker-compose:

I'm trying to Dockerize a classic NodeJS (Express, TS) + Angular application using nginx, but I struggle binding correctly my api throught nginx.

In fact, it seems that nginx target my localhost:80...

...while I want it to target my localhost:3000. When I manually ping that url while adding :3000 after localhost, it works.

I'm trying to keep my code simple. Here are my different files.

Back Dockerfile :

I'm using docker-compose to run tests for my app. My docker-compose.yml file has three services, one for mongodb, one for my app, and a third for my tests. I have logging: driver: "none" set for the app and mongodb because I only want to see the test logs.

This previously worked as expected. Since the last time I worked on this project, I've upgraded docker desktop on my mac to Version 3.5.2 (3.5.2.18). Now, all container logs flood my terminal when running. I'm not sure what has changed.

The issue has appeared recently and the previously healthy container now enters a sleep loop when a shutit session is being created. The issue occurs only on Cloud Run and not locally.

Minimum reproducible code:

requirements.txt