How to Create a network namespace and run a simple web server in it

1)
Add a namespace
#sudo ip netns add myns1

2)
List all namespaces
#ip netns list

3)
Execute commands in a namespace
#sudo ip netns exec myns1 your-command

4)
Check all the interfaces and their IP in the namespace myns1
#sudo ip netns exec myns1 ifconfig -a
#sudo ip netns exec myns1 ip link list

5)
The default interface "lo" in the namespace myns1 doesn't have any IP. So set it like.
#sudo ip netns exec myns1 ifconfig lo 127.0.0.1 up
#sudo ip netns exec myns1 ifconfig -a

6)
Create an index.html
#vim index.html

7)
Run a simple web server on port 80, in namespace "myns1", using netcat command.
#sudo ip netns exec myns1 netcat -l 80 < index.html

8)
Access your webserver from the same namespace "myns1"
#sudo ip netns exec myns1 wget http://127.0.0.1:80