Essential Container Concepts

Essential Container Concepts:

##Network namespace:
	Adding new network namespace:
		$ sudo ip netns add sample1
	Print ip network namespaces list:
		$ sudo ip netns list
	Enter into network namespace (as root):
		$ sudo ip netns exec sample1 bash
		Add iptable rule to the network namespace:
			$iptables -A INPUT -p tcp --dport 80 -j ACCEPT
		Print iptable rules:
			$ iptable -L
		Exit from network namspace:
			$ exit
## CHROOT:
	Creating basic chrooted environment:
		Create a directory for elba within the /home directory:
			$ mkdir /home/elba
		Create a new user for your environment named napoleon:
			$ useradd napoleon
		Create two new directories, bin and lib64, within the /home/elba directory:
			$ mkdir /home/elba/{bin,lib64}
		Copy /bin/bash into /home/elba/bin/bash:
			$ cp /bin/bash /home/elba/bin/bash
		Copy /usr/bin/ls into /home/elba/bin/ls:
			$ cp /bin/ls /home/elba/bin/ls
		Copy /bin/cat into /home/elba/bin/cat:
			$ cp /bin/cat /home/elba/bin/cat
		Copy the libraries needed for bash, ls, and cat over to /home/elba/lib64.
			*Important note - There's OS's versions, as ubuntu18.04LTS that actually stores those libraries in 2 locations - 
				/lib/x86_64-linux-gnu/ & /lib64/ - if that's your scenario(you'll see after enter ldd),
				you should create the exact libraries folder as your 'actual root' orginized it, please enter:
					$ sudo mkdir /home/elba/lib && sudo mkdir /home/elba/lib/x86_64-linux-gnu.
			Find and copy the libraries needed for bash, ls, and cat over to /home/elba/lib64:
				$ sudo ldd /bin/bash /bin/ls /bin/cat
				$ sudo cp /lib/x86_64-linux-gnu/libtinfo.so.5 /lib/x86_64-linux-gnu/libdl.so.2 \
				/lib/x86_64-linux-gnu/libc.so.6 /lib/x86_64-linux-gnu/libselinux.so.1 \
				/lib/x86_64-linux-gnu/libc.so.6 /lib/x86_64-linux-gnu/libpcre.so.3 \
				/lib/x86_64-linux-gnu/libdl.so.2 /lib/x86_64-linux-gnu/libpthread.so.0 \
				/lib/x86_64-linux-gnu/libc.so.6 /home/elba/lib/x86_64-linux-gnu
				$ sudo cp /lib64/ld-linux-x86-64.so.2 /home/elba/lib64/
		Using vi, create the waterloo.txt file in the /home/elba directory with instructions on how to escape:
			vi /home/elba/waterloo.txt
		Using the chroot command, create a chrooted environment in /home/elba with a Bash shell:
			$ chroot /home/elba /bin/bash
		Using the command pwd, confirm the present working directory and then confirm that you can use the ls command:
			$ pwd
			$ ls
			$ cat
		View the contents of waterloo.txt and find out how to escape your environment:
			$ cat waterloo.txt