Information

Sample "Hello world" web server written in GO and shell packed as image using Alpine linux as base image.

The images are hosted on Docker Hub https://hub.docker.com/r/perteghella/hello-shell
Source code on Github https://github.com/Perteghella/hello-shell

There are also images based on Ubuntu, Debian, Google Distroless, Busybox and Scratch to understand that size matters

• golang:1.23.1 https://hub.docker.com/_/golang
• alpine:3.20.3 https://hub.docker.com/_/alpine
• busybox:1.37.0 https://hub.docker.com/_/busybox
• debian:bookworm 12.7 https://hub.docker.com/_/debian
• ubuntu:24.04 https://hub.docker.com/_/ubuntu
• redhat/ubi9:9.4 https://hub.docker.com/r/redhat/ubi9/
• distroless https://github.com/GoogleContainerTools/distroless

Versions

This application is available as OCI images based on Alpine on Docker Hub, which respond to requests with different version numbers:

• perteghella/hello-shell:1.0
• perteghella/hello-shell:2.0

The images are based on sample hello-app

Key features

• Multi architecture build
  • linux/amd64
  • linux/arm64
• Minimal size due to multistage build
• Multiple tag to test the migration to different version of deployment
• Minimal web server that expose version and headers
• env var PORT to change the server port, default to 8080

How to use this image with Docker cli

Download the proper tagged image docker pull perteghella/hello-shell:TAG

docker pull perteghella/hello-shell:1.0

Run as daemon exposing localhost port 8000 to port 8080 on container

docker run -d -p 8000:8080 --name hello-shell-1.0 perteghella/hello-shell:1.0

Verify that container is running

docker ps

Sample output

CONTAINER ID   IMAGE                           COMMAND        CREATED         STATUS          PORTS                    NAMES
c135f955a4d5   perteghella/hello-shell:1.0     "/hello-app"   1 minutes ago   Up 1 minutes    0.0.0.0:8000->8080/tcp   hello-shell-1.0

Verify that web server is responding to request

curl http://127.0.0.1:8000

Attach to shell using

docker exec -it hello-shell-1.0 /bin/sh

Inside the container execute some linux commands

hostname
ifconfig
ping 1.1.1.1
exit

Stop and destroy the container

docker rm  -f hello-shell-1.0

Code

Source on Github https://github.com/Perteghella/hello-shell

Build the image

Build and push the images based on Alpine to Docker hub

docker buildx build --platform linux/amd64,linux/arm64 --build-arg APP_VERSION=1.0 --tag perteghella/hello-shell:1.0 --push .
docker buildx build --platform linux/amd64,linux/arm64 --build-arg APP_VERSION=2.0 --tag perteghella/hello-shell:2.0 --push .

Build using different base image

Using different Dockerfiles we build and save the image locally

docker buildx build --build-arg APP_VERSION=1.0-scratch -f Dockerfile-scratch --tag perteghella/hello-shell:1.0-scratch  --load .
docker buildx build --build-arg APP_VERSION=1.0-busybox -f Dockerfile-busybox --tag perteghella/hello-shell:1.0-busybox  --load .
docker buildx build --build-arg APP_VERSION=1.0-alpine -f Dockerfile --tag perteghella/hello-shell:1.0-alpine  --load .
docker buildx build --build-arg APP_VERSION=1.0-debian -f Dockerfile-debian --tag perteghella/hello-shell:1.0-debian  --load .
docker buildx build --build-arg APP_VERSION=1.0-ubuntu -f Dockerfile-ubuntu --tag perteghella/hello-shell:1.0-ubuntu  --load .
docker buildx build --build-arg APP_VERSION=1.0-distroless-debian12 -f Dockerfile-distroless-debian12 --tag perteghella/hello-shell:1.0-distroless-debian12  --load .

Get the images sizes

docker image ls 

Look the size of the images based on alpine, busybox and scratch + a shell

REPOSITORY                    TAG                IMAGE ID       CREATED              SIZE
gcr.io/distroless/static-debian12   latest       125bac032e5e   N/A                  1.99MB
busybox                       1.37.0             63cd0d5fb10d   5 days ago           4.04MB
alpine                        3.20.3             c157a85ed455   3 weeks ago          8.83MB
ubuntu                        24.04              c22ec0081bf1   2 weeks ago          101MB
debian                        bookworm           a2a098df5635   5 days ago           139MB
redhat/ubi9                   9.4                34c69b3786d8   13 days ago          231MB
perteghella/hello-shell       1.0-scratch        dcd6ba149a7d   1 minutes ago        9.45MB
perteghella/hello-shell       1.0-distroless-debian12  b3312b39c788  4 seconds ago   10.3MB
perteghella/hello-shell       1.0-busybox        f941dd6ac2cf   1 minutes ago        11.3MB
perteghella/hello-shell       1.0-alpine         1df31cf51d68   1 minutes ago        16MB
perteghella/hello-shell       1.0-ubuntu         1c2a0f395005   7 seconds ago        108MB
perteghella/hello-shell       1.0-debian         d2309d0c3760   51 seconds ago       146MB
perteghella/hello-shell       1.0-rh9            d9565b5ac8b8   10 seconds ago       238MB

Build and push the images based on Scratch, Busybox, Ubuntu and Debian

As reference you can use also this TAGs for the image from Docker Hub, sorted by image size.

• perteghella/hello-shell:1.0-scratch
• perteghella/hello-shell:1.0-distroless-debian12
• perteghella/hello-shell:1.0-busybox
• perteghella/hello-shell:1.0-alpine
• perteghella/hello-shell:1.0-debian
• perteghella/hello-shell:1.0-ubuntu
• perteghella/hello-shell:1.0-rh9

THe images are built with this commands

docker buildx build --platform linux/amd64,linux/arm64 --build-arg APP_VERSION=1.0-scratch -f Dockerfile-scratch --tag perteghella/hello-shell:1.0-scratch --push .
docker buildx build --platform linux/amd64,linux/arm64 --build-arg APP_VERSION=1.0-distroless-debian12 -f Dockerfile-scratch --tag perteghella/hello-shell:1.0-distroless-debian12 --push .
docker buildx build --platform linux/amd64,linux/arm64 --build-arg APP_VERSION=1.0-busybox -f Dockerfile-busybox --tag perteghella/hello-shell:1.0-busybox --push .
docker buildx build --platform linux/amd64,linux/arm64 --build-arg APP_VERSION=1.0-busybox -f Dockerfile --tag perteghella/hello-shell:1.0-alpine --push .
docker buildx build --platform linux/amd64,linux/arm64 --build-arg APP_VERSION=1.0-debian -f Dockerfile-debian --tag perteghella/hello-shell:1.0-debian --push .
docker buildx build --platform linux/amd64,linux/arm64 --build-arg APP_VERSION=1.0-ubuntu -f Dockerfile-ubuntu --tag perteghella/hello-shell:1.0-ubuntu --push .
docker buildx build --platform linux/amd64,linux/arm64 --build-arg APP_VERSION=1.0-rh9 -f Dockerfile-rh9 --tag perteghella/hello-shell:1.0-rh9 --push .