Enables remote Docker image builds using docker compose & adds support for passing ENV variables

[oliveratgithub]

Summary

Allows building docker image using docker compose remotely, and for this also adds support for passable process ENVIRONMENT variables - not failing when no dedicated .env-file is being mapped / available.

$ DOCKER_BUILDKIT=1 docker build -t teleirc:docker-demo \
  "https://github.com/RITlug/teleirc.git#1b1002b5636b967a35b1a172298985e9994bf4bf" \
  -f deployments/container/Dockerfile
$ docker run -d --name teleirc \
  -e IRC_SERVER=chat.freenode.net \
  -e IRC_CHANNEL='#channelname' \
  -e IRC_BOT_NAME='teleirc' \
  -e TELEIRC_TOKEN='000000000:AAAAAAaAAa2AaAAaoAAAA-a_aaAAaAaaaAA' \
  -e TELEGRAM_CHAT_ID='-0000000000000' \
  --user teleirc \
  teleirc:docker-demo

Note

This addresses the Docker build error "/app/.env": not found originally mentioned in #228

Detail changelog

• Uses most recent golang:1.25-alpine version for the Docker image
• Adds support to pass an env variable DEBUG=true to enable verbose logging
• No longer fails to build the Image when an .env-file is missing to copy at build-time
  • either use the CLI argument docker compose … --env-file /path/to/.env
  • or use a volumes:-mapping in the docker-compose.yml service definition
• Updates the documentations
  • Quick Start Deployment Guide » Run Container with a docker compose examples
  • Adds the DEBUG env var to the Config file glossary