Argo Rollouts in Production: Canary, AnalysisTemplates, and the Gotchas Nobody Documents

It started with a routine Tuesday deploy. Nothing fancy, a small config change to our ingress controller across a few clusters. We'd done this a hundred times. Standard values.yaml modification and then letting ArgoCD do its magic, watch the rolling update do its thing, grab a Tea ( personal preference, you can grab a coffee as well ). Famous last words. By the time I checked the dashboards, three clusters were throwing 502s. The rolling update had dutifully cycled through pods, but it had no cl