polster’s gists

polster / rbenv-brew-setup.sh

Created May 12, 2017 12:17

Ruby: Install Ruby Version with rbenv and homebrew on macOS

	# Install
	brew install rbenv ruby-build

	# List available ruby versions
	rbenv -l

	# Install the required ruby version
	rbenv install 2.4.1
	rbenv global 2.4.1

polster / iptables-config.sh

Last active April 24, 2024 13:16

iptables: Sample Configuration

	#!/bin/sh

	# Abort script when command exits with error
	set -e

	# Print each command before it is executed (only for debugging)
	#set -x

	########################################################################
	# Config

polster / ssh-copy.sh

Created March 9, 2017 09:16

SSH: Key distribution

	# On systems without ssh-copy-id:
	cat ~/.ssh/id_rsa.pub \| ssh <user>@<hostname> 'umask 0077; mkdir -p .ssh; cat >> .ssh/authorized_keys && echo "Key copied"'

	# Or:
	ssh-copy-id -i ~/.ssh/id_rsa.pub <user>@<hostname>

polster / httpd-vhost-php-minimal.conf

Created March 2, 2017 07:45

Apache: Minimal vhost sample for serving a PHP app

	<VirtualHost 172.4.16.23:80>
	DocumentRoot /opt/httpd/vhosts/wp.example.com/htdocs
	ServerName wp.example.com
	ServerAlias community-new.hintest.ch
	ErrorLog /opt/httpd/logs/error.wp.example.com.srv-web01.log
	CustomLog /opt/httpd/logs/access.wp.example.com.srv-web01.log combined

	# Inherit Rewrite Rules from httpd.conf
	RewriteEngine On
	RewriteOptions InheritBefore

polster / virtualbox-shared-folder.sh

Created March 1, 2017 14:27

Virtualbox: How to add share a local folder with the Linux Guest

	# Ensure the local folder to be shared with the guest has been configured in VirtualBox (Menu > Devices > Shared Folders)

	# Create local mount point, assuming the shared folder's name corresponds to Downloads
	mkdir -p Shares/VBox/Downloads

	# Mount by specifying the right user/group id plus mount filesystem type
	sudo mount -o uid=1000,gid=1000 -t vboxsf Downloads ~/Shares/VBox/Downloads/

polster / docker-dns-fixing.sh

Last active February 28, 2017 14:47

Docker: How to fix Docker DNS problems

	# Login to your Docker host

	# Print the Docker host's configured DNS servers
	nmcli dev show \| grep 'IP4.DNS'

	# Run the following command in order to check if DNS resolution within the container is working (using one of the DNS servers)
	docker run --dns <dns host or ip> busybox nslookup google.com

	# In case there are no errors and resolution works, we may apply a system wide fix (adjust the DNS entries as needed):
	echo "{

polster / macos-terminal-gatekeeper.sh

Created January 30, 2017 07:54

macOS: Allow Gatekeeper untrusted apps

	# Check if a specific app has been quarantined by Gatekeeper
	➜ ~ xattr Applications/Eclipse.app
	com.apple.quarantine

	# Remove the app from the quarantine
	➜ ~ sudo xattr -r -d com.apple.quarantine Applications/Eclipse.app

polster / configure-nrpe.yml

Created January 12, 2017 22:53

Ansible: Replace key value in config file

	- name: "NRPE config: Update hosts allowed to call the NRPE agent"
	replace:
	dest: "{{ ansible_nagios_nrpe_config_file }}"
	replace: 'allowed_hosts={{ ansible_nagios_nrpe_source_hosts }}'
	regexp: 'allowed_hosts=\s([^\n\r])'
	notify:
	- Restart NRPE agent
	- Run NRPE check
	- Assert NRPE check was successful

polster / defaults-main.yml

Last active January 1, 2017 00:12

Ansible: Trigger certain installation or setup tasks over a self managed version file (sample)

	# Ansible role's default vars
	---

	# The NRPE version
	ansible_nagios_nrpe_version: "3.0.1"

	# Allows to force a re-installation
	ansible_nagios_nrpe_reinstall_force: false

polster / ssl-ca-signed-certs.sh

Created December 26, 2016 13:53

SSL Certs: Root CA with client and server certs signing sample

	# Create root CA
	openssl genrsa -aes256 -out ca-key.pem 4096
	openssl req -new -x509 -days 365 -key ca-key.pem -sha256 -out ca.pem

	# Create Server key and CSR
	openssl genrsa -out server-key.pem 4096
	openssl req -subj "/CN=docker-node01-dev" -sha256 -new -key server-key.pem -out server.csr

	# Create trusted Server Certificate
	echo subjectAltName = DNS:docker-node01-dev,IP:192.168.9.70,IP:127.0.0.1 > extfile.cnf

Simon Dietschi polster