Stern has been around for ever. You could also just use a shared label selector with kubectl logs and then grep from there. You make it sound difficult if not impossible, but it's not. Combine it with egrep and you can pretty much do anything you want right there on the CLI
I don't know how k8s works; but if there is a way to execute just one command in a container and then exit out of it like chroot; wouldn't it be possible to just use xargs with a list of the container names?
This is what I was thinking. And you can't really graph out things over time on a graph which is really critical for a lot of workflows.
I get that Splunk and Elastic or unwieldy beasts that take way too much maintenance for what they provide for many orgs but to think grep is replacement is kinda crazy.
Since you are talking about pods, you are obviously emitting all your logs on stdout and stderr, and you have of course also labeled your pods nicely, so grepping all 36 gods is as easy as kubectl logs -l <label-key>=<label-value> | grep <search-term>
Syslog isn't really overkill IMO. It's pretty easy to configure it to log to a remote server, and to split particular log types or sources into different files. It's a decent abstraction - your app that logs to syslog doesn't have to know where the logs are going.