Self signed ssl nginx

docker-compose.yml

version: '3.7'

services:
  nginx:
    image: nginx:alpine
    command: >
      sh -c "
      apk add openssl &&
      mkdir -p /var/www/backend/certs/ &&
      cd /var/www/backend/certs/ &&
      openssl req -x509 -nodes -days 365 -newkey rsa:2048 -subj \"/C=/ST=/L=/O=/CN=\" -keyout default.key -out default.crt &&
      nginx -g \"daemon off;\""
    volumes:
      - ./nginx.conf:/etc/nginx/conf.d/default.conf:ro
    restart: unless-stopped
    ports:
      - 443:443

nginx.conf

upstream bar {
    server somewhere
}

server {
    listen 443 ssl http2;

    ssl_certificate     /var/www/backend/certs/default.crt;
    ssl_certificate_key /var/www/backend/certs/default.key;

    location /foo/ {
        proxy_pass http://bar/;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header Host $host;
        proxy_redirect off;
    }
}