One thing about Docker is, it makes it very easy to deal with containers and managing them. Simple by an one-liner we can run any container like so:
docker container run -dp 80:80 nginx:alpine
Want to have ten Nginx running simultaneously? No problem
for N in {1..10}; do
docker container run --rm -dp 8${N}:80 --name nginx_${N} nginx:alpine
done
And here is a shot of it:
Or the output:
docker container ls
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
25bec68cb5f0 nginx:stable-alpine "/docker-entrypoint.…" 29 seconds ago Up 23 seconds 0.0.0.0:810->80/tcp, :::810->80/tcp nginx_10
42817975af5c nginx:stable-alpine "/docker-entrypoint.…" 33 seconds ago Up 28 seconds 0.0.0.0:89->80/tcp, :::89->80/tcp nginx_9
fc0bb78c7652 nginx:stable-alpine "/docker-entrypoint.…" 37 seconds ago Up 33 seconds 0.0.0.0:88->80/tcp, :::88->80/tcp nginx_8
d40c639f35e7 nginx:stable-alpine "/docker-entrypoint.…" 42 seconds ago Up 37 seconds 0.0.0.0:87->80/tcp, :::87->80/tcp nginx_7
78312e3e8a4d nginx:stable-alpine "/docker-entrypoint.…" 48 seconds ago Up 42 seconds 0.0.0.0:86->80/tcp, :::86->80/tcp nginx_6
bec616fe6e3c nginx:stable-alpine "/docker-entrypoint.…" 53 seconds ago Up 48 seconds 0.0.0.0:85->80/tcp, :::85->80/tcp nginx_5
f8ea11810a30 nginx:stable-alpine "/docker-entrypoint.…" 58 seconds ago Up 53 seconds 0.0.0.0:84->80/tcp, :::84->80/tcp nginx_4
5300c419a04e nginx:stable-alpine "/docker-entrypoint.…" About a minute ago Up 58 seconds 0.0.0.0:83->80/tcp, :::83->80/tcp nginx_3
7c8a6fa2ede7 nginx:stable-alpine "/docker-entrypoint.…" About a minute ago Up About a minute 0.0.0.0:82->80/tcp, :::82->80/tcp nginx_2
941453ac23a9 nginx:stable-alpine "/docker-entrypoint.…" About a minute ago Up About a minute 0.0.0.0:81->80/tcp, :::81->80/tcp nginx_1
So not just 10 containers we can run as many as we want but what do they do for us? If you have 10 or 1000 Nginx containers? And from now networking comes to the play because if we want to join to different containers to communicate with each other we have to connect them to each other and this connection is possible through networking.
The bigger or the more complex our containers' communication is, the more depth understanding is needed about networking. Thus lets go to next part.
