Fabio Mendes fabiojmendes

Enable persistent storage for the systemd journal log

Overview

The assumed default setting in /etc/systemd/journald.conf is Storage=auto which implies that systemd journaling will only persist the journal if the expected storage location is available. Otherwise, the journal data is stored in memory and lost between reboots. On Ubuntu 16.04, /var/log/journal does not exist by default. Create it to keep and query events from previous boots.

Considerations:

Syslog still provides the persistant log records for Ubuntu 16.04, so enabling persistant systemd journal logging does cause a level of duplicaiton.
There are sane defaults:

Docker compose as a systemd unit

Create file /etc/systemd/system/[email protected]. SystemD calling binaries using an absolute path. In my case is prefixed by /usr/local/bin, you should use paths specific for your environment.

[Unit]
Description=%i service with docker compose
PartOf=docker.service
After=docker.service

Running docker-compose as a systemd service

Files

File	Purpose
`/etc/compose/docker-compose.yml`	Compose file describing what to deploy
`/etc/systemd/system/docker-compose.service`	Service unit to start and manage docker compose
`/etc/systemd/system/docker-compose-reload.service`	Executing unit to trigger reload on `docker-compose.service`
`/etc/systemd/system/docker-compose-reload.timer`	Timer unit to plan the reloads

Put zfs.py into a directory (e.g. /opt/collectd-plugins). Load with, e.g.:

LoadPlugin python
<Plugin "python">
  ModulePath "/opt/collectd-plugins"
  Import "zfs"
</Plugin>

Load zfs.json and zfs_arc.json into Grafana. They assume the data is saved in a Grafana dataset named collectd.

	#To create a classic TCP listening daemon, similar to netcat -l, use a variation of the following command.
	socat TCP-LISTEN:8080 stdout

	#use remotly a command shell
	socat TCP4-LISTEN:1234,reuseaddr,fork 'SYSTEM:/bin/cat /home/infos.txt'

	#sslify a server
	socat OPENSSL-LISTEN:443,reuse‐addr,pf=ip4,fork,cert=server.pem,cafile=client.crt TCP4-CONNECT:localhost:80

	/*
	* Convert from OpenCV image and write movie with FFmpeg
	*
	* Copyright (c) 2016 yohhoy
	*/
	#include <iostream>
	#include <vector>
	// FFmpeg
	extern "C" {
	#include <libavformat/avformat.h>

	version: '3'

	services:
	traefik:
	image: traefik:v2.0
	container_name: traefik
	restart: unless-stopped
	security_opt:
	- no-new-privileges:true
	networks:

	import adsk.core
	import adsk.fusion
	import csv
	import os
	import os.path

	# Inspired by: https://forums.autodesk.com/t5/fusion-360-design-validate/parts-list-with-dimensions/m-p/9642058/highlight/true#M223047


	def run(context):

	#!/bin/bash

	curl https://www.cloudflare.com/ips-v4 > .ips-v4
	curl https://www.cloudflare.com/ips-v6 > .ips-v6

	firewall-cmd --new-zone=cloudflare --permanent
	firewall-cmd --reload

	for i in `<.ips-v4`; do firewall-cmd --zone=cloudflare --add-source=$i; done
	for i in `<.ips-v6`; do firewall-cmd --zone=cloudflare --add-source=$i; done