Enable buildkit in docker and use heredoc feature

Why buildkit?
– Better build logs
– Better build cache

Temp enable buildkit

nginx.Dockerfile

# syntax=docker/dockerfile:1.3-labs
FROM nginx

COPY <<EOF /usr/share/nginx/html/index.html
"hola Duniya"
EOF

DOCKER_BUILDKIT=1 docker build -t here-nginx -f nginx.Dockerfile .

Enable buildkit permanently :

echo "{ "features": { "buildkit": true } }" > /etc/docker/daemon.json


systemctl restart docker

More : https://github.com/moby/buildkit

Introduction to heredocs in Dockerfiles