Network
What Are HTTP Status Codes Developers Actually Meet
The HTTP status codes developers actually meet, grouped by meaning, with what scripts should do for each, retries, redirects and curl options.
6 min read
Topic
Network
SSH, curl, DNS, ports and HTTP APIs from the terminal, for when a connection or a request will not behave.
Network
What Is REST and How It Differs From RPC and GraphQL
REST, RPC and GraphQL compared: resources versus actions versus queries, caching, versioning, tooling with curl, error handling and how to choose.
6 min read
Network
How to Debug DNS and TLS Problems From the Terminal
Debug DNS and TLS problems from the terminal: dig, getent and resolvectl for names, openssl s_client and curl -v for handshakes, with a layered approach.
6 min read
Network
SSH Connection Timed Out and Firewall Problems Fully
Fix SSH Connection timed out: tell it from refused, trace the path with nc and traceroute, check firewalls and security groups, and set ConnectTimeout.
6 min read
Network
SSH Connection Refused and What to Check First Explained
Fix SSH connection refused: confirm sshd is running and listening, the port and address, firewall rules, and how it differs from a timeout.
6 min read
Network
SSH Permission Denied Publickey Causes and Fixes Fully
Fix SSH Permission denied (publickey): read ssh -v output, check the key, the agent, file permissions on both sides, the user name and sshd logs.
6 min read
Network
SSH Subsystem Request Failed on Channel 0 With sftp
Fix SSH subsystem request failed on channel 0 with sftp or scp: a missing Subsystem line, wrong sftp-server path, shell startup output and chroots.
6 min read
Automation
How to Use Retries and Rate Limits With curl in Scripts
Retry curl requests safely with --retry flags, respect 429 and Retry-After, add backoff and jitter, throttle requests, and avoid repeating unsafe calls.
6 min read
Automation
How to Use curl in Scripts to Call APIs and Handle Errors
Call APIs from shell scripts with curl and handle errors properly: fail flags, status codes, timeouts, jq parsing and a request function.
6 min read
Network
How to Build a Tiny JSON API With Python or Go for Scripts
Build a tiny JSON API in Python or Go for scripts and tests: a few routes, JSON in and out, status codes, a fake backend and safe local binding.
7 min read
Network
How to Keep API Keys Out of Scripts and Repos the Right Way
Keep API keys out of scripts and repositories: env files, secret managers, scanning for leaks, narrow scopes and what to do after a key escapes.
7 min read
NetworkGuide
SSH From the Basics to a Hardened and Scripted Setup
An SSH guide from first login to a hardened, scripted setup: keys, config files, agents, tunnels, jump hosts, sshd hardening, automation and troubleshooting.
36 min read
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