This repository contains scripts and documentation focused on creating customized Docker images and sending them to Kubernetes. This is a guide for developers, focused on simplicity.
In the first step a minimalistic Docker image of Ubuntu was found.
With the following Dockerfile:
FROM phusion/baseimage:latest
RUN apt-get update
RUN apt-get -y install iputils-ping
RUN apt-get -y install mc
there are ping, curl and telnet commands available. The image weights 279 MB:
REPOSITORY TAG SIZE
tiny-ubuntu v1 279MB
Start shell/cmd and run the following in the same directory where the Dockerfile is placed:
docker-compose build
Verify that the image has been created successfully:
docker images --all
it result in something like:
REPOSITORY TAG IMAGE ID CREATED SIZE
ubuntu latest b47cb2d60bbe 39 hours ago 122MB
tiny-ubuntu v1 a77509368a8d 4 months ago 225MB
Start the image (which will result in creating a container):
docker run tiny-ubuntu:v1
View the created container:
docker ps
It should display something like:
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
8d9736464db0 tiny-ubuntu:v1 "/sbin/my_init" 5 minutes ago Up 5 minutes nervous_shaw
From right now we will use a kind of random number 8d9736464db0 - this is the container ID, which will be different in your session. Run the Linux shell in container:
docker exec -it 8d9736464db0 bash
Verify the ping command is available:
root@e5a676c2ff47:/# ping -c 4 windity.com
PING windity.com (139.162.210.148) 56(84) bytes of data.
64 bytes from li1373-148.members.linode.com (139.162.210.148): icmp_seq=1 ttl=37 time=0.429 ms
64 bytes from li1373-148.members.linode.com (139.162.210.148): icmp_seq=2 ttl=37 time=0.825 ms
64 bytes from li1373-148.members.linode.com (139.162.210.148): icmp_seq=3 ttl=37 time=0.746 ms
64 bytes from li1373-148.members.linode.com (139.162.210.148): icmp_seq=4 ttl=37 time=0.825 ms
--- windity.com ping statistics ---
4 packets transmitted, 4 received, 0% packet loss, time 3131ms
rtt min/avg/max/mdev = 0.429/0.706/0.825/0.164 ms
root@e5a676c2ff47:/#
Kill the container:
docker container kill 8d9736464db0