Rohan rohan-molloy

Lookup BGP info of IP

Print a JSON contaning AS,BGP Preifx,CC,Registry,Allocatted of IP address

#! /bin/bash
[[ -z $1 ]] && exit -1; 
ptr=$(tac -s.<<<"$1.");
printf "{\"AS\":%d,\"BGP Prefix\":\"%s\",\"CC\":\"%s\",\"Registry\":\"%s\",\"Allocated\":\"%s\"}\n" `dig "$ptr"origin.asn.cymru.com txt +short | tr -d '\"|'`;

Get src of SSH login fails sorted by IP

journalctl --unit=sshd.service --boot \
| awk '/Failed/' \
| grep -oP '(?<=from )[^ ]*' \
| sort --numeric-sort \
| uniq --count --repeated \

| sort --numeric-sort --reverse

Grep the word after match

example: "echo 'The quick brown fox' | wordafter quick" will return 'brown'

wordafter() {
  word="$1";
  grep -Po '(?<='$word')\W*\K[^ ]*';
}

Bridge (macvlan) in docker-compose

networks:
  extbridge:
     driver: macvlan
     driver_opts:
       parent: enp5s0.10
       macvlan_mode: bridge
     enable_ipv6: true

ipam:

Network Isolation of Services with Systemd

Network namespaces are an important component of containerization in Linux. A network namespace (netns) allows a running process to see different network interfaces, routes, and firewall rules from the rest of the system. There are a number of use cases for network namespaces, such as running multiple servers, testing/staging environments and providing isolation of services.

Creating a Network Namepsace

We begin by creating a generic systemd service for creating a named network namespace. I add the following to /usr/lib/systemd/system/[email protected]. In systemd, the @ mean the service takes a parameter which is passed to the unit via %i. E.g, we can run sudo systemctl start [email protected].

	- hosts: all
	remote_user: root
	vars:
	nameserver: '1.1.1.1'
	tasks:
	- file:
	path: /etc/resolv.conf
	attr: -i
	- copy:
	dest: /etc/resolv.conf

	version: "2.1"
	networks:
	default:
	driver: bridge
	driver_opts:
	com.docker.network.bridge.host_binding_ipv4: "127.0.0.1"
	com.docker.network.bridge.name: ${BRIDGE_NAME}
	ipam:
	driver: default
	config:

	driver:
	name: proxy
	host: <%= ENV["kitchen_host"] %>
	username: <%= ENV["kitchen_username"] %>
	password: <%= ENV["kitchen_password"] %>
	port: 5985
	transport:
	name: winrm
	elevated: true
	provisioner:

	curl \
	--silent \
	--ssl smtp://$SERVER \
	--mail-from $FROM \
	--mail-rcpt $TO \
	--upload-file /dev/stdin \
	--user $USER:$PASSWORD

	#! /bin/bash
	echo \
	\| openssl s_client -connect $1 -CAfile $CAfile \
	\| openssl x509 -noout -pubkey \
	\| ssh-keygen -vi -m PKCS8 -f /dev/stdin \
	\| ssh-keygen -vlf /dev/stdin