It's Always DNS: A Tech Support Saga of Azure, VNETs, and Deployment Woes
If you’ve worked in IT, you know there are a few universal truths: printers are evil, "Have you tried turning it off and on again?" solves half your tickets, and… it’s always DNS. Today, we’re diving into a tale from the trenches—a story that proves, once again, that DNS is the final boss of tech support.
Imagine you're tasked with moving a suite of internal apps across clouds and tenants, navigating paperwork, tight timelines, and the ever-watchful gaze of upper management. You’ve survived the bureaucracy. You’ve wrangled with npm and custom registries. You finally deploy—and then, just when you think you’re out of the woods, DNS rises like Godzilla from Tokyo Bay.
The Great Cloud Split: Bureaucracy Meets Reality
Our story begins with a company doing what companies do best: making things complicated. In their "infinite wisdom," they decided to split into two entities, which means our heroic tech support pro (let’s call him Yami, after his Reddit handle u/KingofGamesYami) now has to migrate apps between Azure tenants. This isn’t just a lift-and-shift. It’s a full migration—new hosting, new authentication via Entra, and a tangle of cloud infrastructure across Azure, AWS, GCP, and on-prem.
But before a single line of code can move, there’s paperwork. So. Much. Paperwork. Weeks pass as timelines are submitted, reviewed, and inevitably declared invalid—because, as Yami wryly notes, work can’t start until the paperwork is approved, but by then, the timelines are already outdated. If Kafka worked in IT, he’d have written this exact scenario.
Deployment Day: From Hope to Headbanging
Finally, the stars align: the paperwork is signed, the infrastructure is ready, and it’s go time. Yami deploys the apps, replicates databases, and dances through a few npm hiccups. Everything launches smoothly. He logs in, clicks around, and the app is humming along. Victory is sweet—and fleeting.
Then, one page fails to load. No problem, right? That’s what logs are for. Only… there are no logs. Application Insights is silent. The connection string is perfect, configs are checked and re-checked, but Yami is left staring into the void.
Now the real fun begins. He dives into KUDU (Azure’s advanced debugging console) and spends hours headbutting the problem from every angle. The day slips away, frustration mounts, and then—epiphany! The app service is VNET-integrated, meaning DNS works a little differently.
As u/Creative-Letter-4902 put it in the comments, "Ah yes, the classic 'DNS but also not DNS because of weird VNET integration' special." There’s even a special tool for this: nameresolver. Yami runs it on the Application Insights endpoint, expecting an IP address. Instead, he gets a confusing mess of aliases pointing to Azure Private Link—which his app doesn’t even use!
DNS: The Hidden Villain of Cloud Deployments
So what happened? In cloud environments, especially when using Azure Virtual Networks (VNETs), DNS resolution can take a detour through private endpoints or internal resolvers. For the uninitiated, as u/lordjippy clarified, "Azure virtual network. Equivalent to AWS VPC." When resources are VNET-integrated, DNS might suddenly resolve to internal addresses, private links, or, in some cases, nothing at all.
As it turns out, the architecture team knew about this problem—it was a "known issue" in progress. Yami's day of headbanging was just another casualty in the long war against DNS quirks. As u/Creative-Letter-4902 put it, "Architecture team sitting on a known issue while you're in the trenches? Yeah, sounds about right." If you ever need a hand untangling these messes, they offered, "I got 2-3 hours free. DM me."
But perhaps the community summed it up best with a haiku from u/Evlavios:
It's not DNS.
There's no way it's DNS.
It was DNS.
If you’ve ever worn the tech support hat, you’re probably nodding along. There’s a reason, as u/skiing123 noted, that you can buy a t-shirt emblazoned with "It’s Always DNS." Because, more often than not, it is.
Lessons Learned (and T-Shirts Earned)
What can we learn from Yami’s odyssey? First, that cloud migrations are like navigating a minefield of paperwork, dependencies, and hidden gotchas. Second, that DNS, especially in the context of modern cloud networking, is even trickier than you think. Third, always check DNS first—save yourself the headache and the forehead-shaped dents in your desk.
And perhaps, as the community’s witty haiku suggests, it’s time to stop denying the obvious. When something breaks, maybe start with DNS and work your way out. At worst, you get to rule it out early. At best, you get to wear the “It’s Always DNS” shirt with pride.
Conclusion: Share Your DNS Nightmares!
Have you ever lost a day (or a week) to a sneaky DNS issue? Do you have a favorite “war story” from the trenches of tech support? Drop your tales below—bonus points for haikus, memes, or photos of your own “It’s Always DNS” swag. And remember: next time you’re deploying to the cloud and something’s not working… just check DNS first.
Happy troubleshooting!
Original Reddit Post: It's always DNS