These are well put together products with a host of great features, such as excellent UIs, sophisticated live searching via web interfaces and sometimes query languages and alerting. They require various levels of installation and they have costs, either through volume-based tiered systems or monthly payments.
For a bootstrapped business, this can be problematic, for instance when a surge of logs - indicating a possible important problem that needs to be solved - pushes volume on to another tier. Should the “log ransom” be paid?
Instead, I recalled from earlier times surely the simplest log watcher: Swatchdog [1]. It is rather venerable software. Its file history from its source download shows dates in 2015, but it was written much earlier - the 90s or possibly 80s by Todd Atkins [2].
We wanted to have alerts in Slack - the blog explains how we did it. In short: *very simply*. The code is available [3].
[1]: https://github.com/ToddAtkins/swatchdog