// DevOps
Practical materials about infrastructure, networking, migrations, releases, and real problems solved in production.
74 DevOps materials published
If your application runs on hundreds of client devices or you have a fleet of sensors with telemetry, sooner or later you’ll need to see what’s happening on the ground. Commercial systems like Splunk or …
Read moreJitsi Meet — an open platform for video conferencing. It can be connected to Active Directory (AD) so that employees sign in with corporate accounts: you don’t need to create users separately, and disabling an …
Read moreThe guide shows how to configure two Linux servers so that all internet traffic from a specific local subnet (for example, 10.100.10.0/24) goes not via its usual gateway but through an IPIP tunnel to a remote server that …
Read moreSometimes all checks pass: ping responds, DNS works, ports are open, mtr shows no loss, but the application still receives errors like connection reset by peer or TLS handshake failed. In those cases you need to look at …
Read moreSimple utilities from previous parts each answer their own question: ping — is there connectivity, traceroute — which path packets take, nc — is the port open. The three tools in this part give a more complete picture: …
Read moreAn IP address identifies a host, and a port identifies a specific service on it. A web server usually accepts connections on port 80 (HTTP) and 443 (HTTPS), SSH on 22, databases and mail on their respective ports. A …
Read moreIt happens: the computer has an address, the router responds, ping 8.8.8.8 works, but websites in the browser do not open. Most often the cause is DNS — the system that translates domain names into IP addresses. If a …
Read moreWhen “the internet is not working”, it’s convenient to check from the bottom up: first your own computer and local network, then connectivity to external nodes, then DNS, ports and applications. This …
Read morecurl — a command-line utility for transferring data via URLs. It sends a request to a server and shows the response: an HTML page, JSON from an API, headers, or a file. The name stands for Client URL. Besides HTTP and …
Read moreDokploy — a free panel for deploying Docker applications on your own server. It handles building from Git, running containers, routing via Traefik and issuing Let’s Encrypt certificates, so you don’t need to …
Read more