mtail VS keychain

You can do that with something like mtail. Basically write expressions that match your logs and produce metrics.

mtail is a standard tool for this.

I use goflow2 to do something like this. I don't specifically use syslog itself for this, but mtail to generate the metrics.

I can recommend mtail. Here is a good example nginx script.

If not, https://github.com/google/mtail might be a good option.

Count the lines with mtail. You can regexp match the values out into labels.

If you want to extract whitebox metrics from logs, maybe all you need is mtail.

You can use mtail (https://github.com/google/mtail) for this. You'll need to figure out how to plug it into your setup, but mtail will do the metrics from logs thing.

Convert your logs to metrics with mtail.

For nginx, you'll need to setup a log parser like mtail because it doesn't really have much for metrics to begin with.

(*) https://github.com/funtoo/keychain. Not updated since 2018 but does the trick very well.

Jon Cairns wrote a similar article about this problem and presented a solution: A script that tries to find and reuse existing ssh-agents. There are multiple scripts with similar approaches all written in bash: ssh_find_agent, zsh-ssh-agent, and the most popular one: keychain. (And later I also discovered envoy). But being bash scripts, they are hard to read, not really fast, and make debugging a hell. I had used keychain successfully until I encountered a problem that I wasn't able to understand. Also, those tools depend heavily on ssh-agent and ssh-add instead of using the socket directly.

For ssh keys, that's what ssh-agent and keychain are for.