In Go, creating goroutines is straightforward, but improper usage may result in a large number of goroutines unable to terminate, leading to resource leakage and memory leaks over time. The key to avoiding goroutine leaks is to manage the lifecycle of goroutines properly. By exporting runtime metrics and utilizing pprof, one can detect and resolve goroutine leakage issues.This post will go through one real case encountered by the author. The author maintains a service that connects to a target machine via SSH and executes commands. This is an internal service that is usually not closely monito...

SSH, short for Secure Shell, is a network protocol used for securely remote logging into other computers on a network. I believe most backend developers are familiar with SSH. Common shell tools used for logging into servers, such as Xshell, SecureCRT, and iTerm2, are all based on the SSH protocol. In Golang, the crypto/ssh package provides functionality for implementing an SSH client. In this article, we will explain in detail how to implement an SSH client using Golang.Creating SSH Client ConfigurationFirst, we need to configure the parameters for the SSH client to connect to the server. The...

SSH is a popular cryptographic network protocol for secure network service operation. It is frequently used in remote server login. For a system administrator or software developer, SSH is frequently used to access remote servers or development servers or testing servers etc. To login with SSH, there are different authentication mechanisms : password, public key and interactive etc. If a remote server needs to be accessed frequently, password authentication may be too troublesome as password needs to be typed every time. In this scenario, public key authentication would be a life sav...

Many people may use FTP and rsync to synchronize codes to server, this way is fine but it may be troublesome when you need to deploy many times a day, actually there is a simple way if you can spend time on finding the fast way. We introduce Fabric today for deploying web app to remote server.Fabric is a deployment tool written with Python, the biggest feature if it is you no need to login to remote server, you can execute remote commands locally.Here is s simple deployment script written with Python : fabfile.py(Do not change the file name). Put it in your project directory.#!/usr/bin/env pyt...

Backstory While at RIT around 2004 or 2005, I discovered that a few important machines at the datacenter allowed all students, faculty, and staff to authenticate against them via ssh. Everyone's shells appear to be set to /bin/false (or some derivative) on said machines, so the only thing you'll see after you authenticate is the login banner and your connection will close. I thought to myself, "Fine, no shell for me. I wonder if port forwarding works?" Seems reasonable, right? Whatever sysadmin was tasked with securing these machines forgot some...