opsops

Modular nftables

multiple tables with the same hook

Every time you want to combine multiple sources of data (and concerns) into iptables, it’s a mess. How can you ‘modularly’ add something into monolithic blob been downloaded from kernel before been uploaded back…

How to check if SSL certificate matches private key?

Usually you undestand this by name. foobar193421.pem and foobar193421_key.pem are belonging to each other, right?

But what if you suspect they are not? I found it’s not a strightforward problem (or I failed to…

Running handlers on each iteration in the included role

Warning: using includes is a bad idea. If you can unroll loop statically, do it statically. Include is a last ‘hope’ for situations when you no longer have other options.

Injecting modules into tests with Pytest

There is a known slightly boring problem with tests. You have conftest.py, which is magical and is always available in tests (but only via hooks and fixtures, and double-magical ‘request’ metafunc). If you want to have it outside fixtures, things become…

Reducing cardinality load from node_systemd_unit_state

We have few alerts for the most critical services, which explicitly checks if service is not failed. This require us to use systemd collector for node exporter, and it gathers a lot of series.

K6 benchmark observations

Grafana K6 is an extremely complex (but nextgen compare to ab/wrk) program. I just started to dive into it, and all I have insofar, is a set of observations for performance limits.

Combining k6, Prometheus remote writes and Vector

to add labels to metrics from k6

Tools:

• k6: a really amazing HTTP benchmarking tool by Grafana.
• Prometheus: a monitoring system, which allow you…

Repeat N times for each element of the list in Ansible

It’s the usual ‘suck at iterations’ problem in Ansible.

My problem:

        mytasks:
          - name: foo
            repeat: 10
          - name: bar
            repeat: 99