noroutine / node-exporter-conntrack-shim

node-exporter conntrack shim

conntrack collector shim for node-exporter

Overview

In recent kernels (like Ubuntu 22.04) NF_CONNTRACK_PROCFS is obsolete and disabled. This prevents conntrack collector from scraping statistics

See prometheus/node_exporter#2491

Symptom is collector silently doesn't work, despite being enabled

node_scrape_collector_success{collector="conntrack"} 0

This shim provides an almost complete substitute via textfile collector

Install

Shim relies on conntrack(8) being available, which is a recommended approach to gathering stats. You also will need Python 3

1. Install conntrack

sudo apt-get -yyq update
sudo apt-get -yyq install python3 conntrack

2. Install the shim

curl -sLo /usr/local/bin/node-exporter-conntrack-shim \
  https://raw.githubusercontent.com/noroutine/node-exporter-conntrack-shim/master/node-exporter-conntrack-shim
chmod +x /usr/local/bin/node-exporter-conntrack-shim

3. Add a cronjob to generate metrics textfile into proper textfiler directory (adjust as needed)

* * * * * root /usr/local/bin/node-exporter-conntrack-shim > /var/lib/node_exporter/node-exporter-conntrack-shim.prom

For example

cat <<EOF > /etc/cron.d/node-exporter-conntrack-shim
* * * * * root /usr/local/bin/node-exporter-conntrack-shim > /var/lib/node_exporter/node-exporter-conntrack-shim.prom
EOF

4. Make sure node-exporter has textfile collector enabled by adding below arguments

  --collector.textfile --collector.textfile.directory=/var/lib/node_exporter

Limitations

node_nf_conntrack_entries_limit and node_nf_conntrack_stat_ignore metrics from collector are missing, since conntrack(8) is not providing this information