Network Overview

Read time 2 minutes

Overview of some services on my network. The setup is fully redundant as high availability cluster. Driven by open source and powered with renewable energy. Network Diagram DMZ Service Description Postfix, Dovecot, SpamAssassin Email Server with DKIM, DMARC, SPF, DANE, Sieve Nextcloud, Collabora Cloud With Mail, Calendar, Contacts, Notes, Tasks, Online Editing of Documents GitlabRead more

Create SWAP on ZFS ZVOL

Read time < 1 minute

ZFS with it’s default options is not great for SWAP usage. If you run “Root on ZFS” you want to create a ZVOL with the right options. This means limiting arc to metadata, disabling l2arc, forcing sync writes, setting logbias to throughput and disabling autosnapshots. Adjust 8G to the swap size you want. Adjust rpoolRead more

Raspberry Pi Grafana Kiosk

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We will use the dashboard that we previously created for reference see https://herold.space/proxmox-grafana-dashboard Prepare Use Etcher to copy Raspberry Pi OS with desktop onto a SD Card. Change the password for “pi” and setup a static IP. Also run updates. Kiosk First enable auto login and disable screen blanking via raspi config cli. The defaultRead more

Proxmox Grafana Dashboard

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InfluxDB First we have to create a time series database to store the metrics. Proxmox only supports Graphite and InfluxDB. I will run InfluxDB via Docker tagged to v1.8 for now. To create a default config run influxd. Proxmox only supports UDP to send metrics which is not enabled by default. We create a UDPRead more

Proxmox Full Disk Encryption with SSH Remote Unlock

Read time 3 minutes

Although ZFS also offers encryption there is no support for full disk encryption yet so we will use LUKS instead. Requirements: ZFS mirror (raid1) install In order to encrypt a running system rpool must be a ZFS mirror. To verify you are running a ZFS mirror execute the following command. Note: If you don’t wantRead more

Login Mail Alert Using Rsyslog

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I wanted a way to know who authenticates on my servers. This is especially useful if you work in a team or want to have some additional security in place. Rsyslogd is a service that ships with most distros which proceeds logs before they are written to disk. We will create a simple script whichRead more

SSH Configuration

Read time 2 minutes

Install SSH Start by installing SSH. Sudo For best practices you should disable root login and create a new user with sudo access. Add the user to the sudo group. Whenever needed you should use sudo to execute binaries with root privileges. To pipe text use sudo in combination with tee. If you know whatRead more

Using Ipsets to Block Tor Anonymity Network

Read time 2 minutes

Besides VPN and SOCKS5 proxies using the Tor anonymity network to scan servers and run brute force attacks is a common choice. It is especially useful to circumvent rate limiting given that you have easy access to a set of over 1500 IP addresses. So if you have your own rate limiting implementation make sureRead more

Compile Linux Kernel

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Most Linux distros ship with a longterm kernel that can be quite old. If you happen to buy new hardware the driver support can be troublesome. So in order to get things like network interfaces, wifi, bluetooth, audio etc. working you might have to build the kernel yourself or switch to a rolling release distro.Read more

Postfix Mail Configuration

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By default Linux distros ship with a internal MTA. If you send local mails they land in /var/mail/<user>. If you want to send external mails you have to configure your MTA to use a relay server. Exim was the default for quite some time but has been replaced with postfix since in many distros. InstallRead more

Copy Files via Shell

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Maybe you are limited and have no SFTP client available or just want a simple fast way to copy some config files from a server. All the tools you need are already installed. To backup the current directory It returns your files compressed and encoded as base64 with owner mappings and file permissions. You canRead more

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