eugenechen0514/ha_baseimage repository overview

⁠A minimal docker baseimage to ease creation of long-lived application containers

This is a docker baseimage that can be used to create containers for any long-lived application.

⁠Images

Different docker images are available:

Base Distribution	Docker Image Base Tag	Size
Alpine 3.13⁠	alpine-3.13
Alpine 3.14⁠	alpine-3.14
Alpine 3.15⁠	alpine-3.15
Alpine 3.16⁠	alpine-3.16
Alpine 3.17⁠	alpine-3.17
Debian 9⁠	debian-9
Debian 10⁠	debian-10
Debian 11⁠	debian-11
Ubuntu 16.04 LTS⁠	ubuntu-16.04
Ubuntu 18.04 LTS⁠	ubuntu-18.04
Ubuntu 20.04 LTS⁠	ubuntu-20.04

⁠Content

Here are the main components of the baseimage:

• An init system.
• A process supervisor, with proper PID 1 functionality (proper reaping of processes).
• Useful tools to ease container building.
• Environment to better support dockerized applications.

⁠Versioning

Images are versioned. Version number follows the semantic versioning⁠. The version format is MAJOR.MINOR.PATCH, where an increment of the:

• MAJOR version indicates that a backwards-incompatible change has been done.
• MINOR version indicates that functionality has been added in a backwards-compatible manner.
• PATCH version indicates that a bug fix has been done in a backwards-compatible manner.

⁠Tags

For each distribution-specific image, multiple tags are available:

⁠Getting started

The Dockerfile for your application can be very simple, as only three things are required:

• Instructions to install the application.
• A script that starts the application (stored at /startapp.sh in container).
• The name of the application.

Here is an example of a docker file that would be used to run a simple web NodeJS server. In Dockerfile:

# Pull base image.
FROM jlesage/baseimage:alpine-3.15-v3

# Install http-server.
RUN add-pkg nodejs-npm && \
    npm install http-server -g

# Copy the start script.
COPY startapp.sh /startapp.sh

# Set the name of the application.
RUN set-cont-env APP_NAME "http-server"

# Expose ports.
EXPOSE 8080

In startapp.sh:

#!/bin/sh
exec /usr/bin/http-server

Then, build your docker image:

docker build -t docker-http-server .

And run it:

docker run --rm -p 8080:8080 docker-http-server

You should be able to access the HTTP server by opening in a web browser:

http://[HOST IP ADDR]:8080

⁠Documentation

Full documentation is available at https://github.com/jlesage/docker-baseimage⁠.