Happy Path Networking¶
Thoughts and experience on network automation and AI, with the emphasis on demonstration over lecture. Everything here is built, run, and measured against real equipment — including the parts that turned out to be wrong.
Written by Josh Gilby. joshgilby · jgilby@happypathnetworking.com
The Quelaag series¶
An engineer changes a local password by hand and makes a typo. From that moment the organisation's record of its own credentials is wrong, and nothing anywhere will notice — not monitoring, not the configuration backup, not the operations staff, whose logins go to TACACS. The gap stays open until the night TACACS is unreachable and the local credentials are all that is left.
These nine articles build Quelaag, a system that closes that gap on its own: it keeps a record of what each device's secrets should be, notices when a device changes, checks the configured secrets against the record, and puts the right value back when they disagree. Each article ends with a working archive you can download and run against real router software on your laptop.
The interesting part is not the automation. It is that the system is deliberately built as several small services rather than one program — a microservice architecture applied to network automation — and that the series says plainly where its own design was wrong.
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Designing before building
The design for the whole system, written before a line of code existed — and the three places it turned out to be mistaken.
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You don't need a rack of routers
Two Cisco routers on your laptop, defined in one file. Plus three ways to reboot one, two of which lie to you.
What's next¶
More network automation, and a strand on AI — same standard of evidence: built, run, and measured rather than asserted.