I'm trying to set up a Django project with docker + nginx following the tutorial Nginx and Let's Encrypt with Docker in Less Than 5 Minutes.

The issue is when I run the script init-letsencrypt.sh I end up with failed challenges.

Here is the content of my script:

#!/bin/bash

if ! [ -x "$(command -v docker-compose)" ]; then
  echo 'Error: docker-compose is not installed.' >&2
  exit 1
fi

domains=(xxxx.yyyy.net www.xxxx.yyyy.net)
rsa_key_size=4096
data_path="./data/certbot"
email="myemail@example.com" # Adding a valid address is strongly recommended
staging=1 # Set to 1 if you're testing your setup to avoid hitting request limits

if [ -d "$data_path" ]; then
  read -p "Existing data found for $domains. Continue and replace existing certificate? (y/N) " decision
  if [ "$decision" != "Y" ] && [ "$decision" != "y" ]; then
    exit
  fi
fi


if [ ! -e "$data_path/conf/options-ssl-nginx.conf" ] || [ ! -e "$data_path/conf/ssl-dhparams.pem" ]; then
  echo "### Downloading recommended TLS parameters ..."
  mkdir -p "$data_path/conf/"
  curl -s https://raw.githubusercontent.com/certbot/certbot/master/certbot-nginx/certbot_nginx/_internal/tls_configs/options-ssl-nginx.conf > "$data_path/conf/options-ssl-nginx.conf"
  curl -s https://raw.githubusercontent.com/certbot/certbot/master/certbot/certbot/ssl-dhparams.pem > "$data_path/conf/ssl-dhparams.pem"
  echo
fi

echo "### Creating dummy certificate for $domains ..."
path="/etc/letsencrypt/live/$domains"
mkdir -p "$data_path/conf/live/$domains"
docker-compose -f docker-compose-deploy.yml run --rm --entrypoint "\
  openssl req -x509 -nodes -newkey rsa:$rsa_key_size -days 1\
    -keyout '$path/privkey.pem' \
    -out '$path/fullchain.pem' \
    -subj '/CN=localhost'" certbot
echo


echo "### Starting nginx ..."
docker-compose -f docker-compose-deploy.yml up --force-recreate -d proxy
echo

echo "### Deleting dummy certificate for $domains ..."
docker-compose -f docker-compose-deploy.yml  run --rm --entrypoint "\
  rm -Rf /etc/letsencrypt/live/$domains && \
  rm -Rf /etc/letsencrypt/archive/$domains && \
  rm -Rf /etc/letsencrypt/renewal/$domains.conf" certbot
echo


echo "### Requesting Let's Encrypt certificate for $domains ..."
#Join $domains to -d args
domain_args=""
for domain in "${domains[@]}"; do
  domain_args="$domain_args -d $domain"
done

# Select appropriate email arg
case "$email" in
  "") email_arg="--register-unsafely-without-email" ;;
  *) email_arg="--email $email" ;;
esac

# Enable staging mode if needed
if [ $staging != "0" ]; then staging_arg="--staging"; fi

docker-compose  -f docker-compose-deploy.yml run --rm --entrypoint "\
  certbot -v certonly --webroot -w /var/www/certbot \
    $staging_arg \
    $email_arg \
    $domain_args \
    --rsa-key-size $rsa_key_size \
    --agree-tos \
    --force-renewal" certbot
echo

echo "### Reloading nginx ..."
docker-compose  -f docker-compose-deploy.yml exec proxy nginx -s reload

And my nginx configuration file:

server {
    listen 80;
    server_name xxxx.yyyy.net;
       
    location ^~ /.well-known/acme-challenge/ {
        root /var/www/certbot;
    }
    
    location / {
        return 301 https://$server_name$request_uri;
    }

}

server {
    listen 443 ssl;
    server_name xxxx.yyyy.net;
    
    ssl_certificate /etc/letsencrypt/live/xxxx.yyyy.net/fullchain.pem;
    ssl_certificate_key /etc/letsencrypt/live/xxxx.yyyy.net/privkey.pem;
    include /etc/letsencrypt/options-ssl-nginx.conf;
    ssl_dhparam /etc/letsencrypt/ssl-dhparams.pem; 
    
    location /static {
        alias /vol/static;
    }

    location / {
        uwsgi_pass web:8000;
        include /etc/nginx/uwsgi_params;
    }

}

The output of the part that fails:

Requesting a certificate for xxxx.yyyy.net and www.xxxx.yyyy.net
Performing the following challenges:
http-01 challenge for xxxx.yyyy.net
http-01 challenge for www.xxxx.yyyy.net
Using the webroot path /var/www/certbot for all unmatched domains.
Waiting for verification...
Challenge failed for domain xxxx.yyyy.net
Challenge failed for domain www.xxxx.yyyy.net
http-01 challenge for xxxx.yyyy.net
http-01 challenge for www.xxxx.yyyy.net

Certbot failed to authenticate some domains (authenticator: webroot). The Certificate Authority reported these problems:
  Domain: xxxx.yyyy.net
  Type:   connection
  Detail: Fetching http://xxxx.yyyy.net/.well-known/acme-challenge/XJw9w39lRSSbPf-4tb45RLtTnSbjlUEi1f0Cqwsmt-8: Connection refused

  Domain: www.xxxx.yyyy.net
  Type:   connection
  Detail: Fetching http://www.xxxx.yyyy.net/.well-known/acme-challenge/b47s4WJARyOTS63oFkaji2nP7oOhiLx5hHp4kO9dCGI: Connection refused

Hint: The Certificate Authority failed to download the temporary challenge files created by Certbot. Ensure that the listed domains serve their content from the provided --webroot-path/-w and that files created there can be downloaded from the internet.

Cleaning up challenges
Some challenges have failed.
Ask for help or search for solutions at https://community.letsencrypt.org. See the logfile /var/log/letsencrypt/letsencrypt.log or re-run Certbot with -v for more details.
ERROR: 1

One of the comments said:

But there's no further explanation as to how to solve it.

Check the certbot commit

Problem is nginx configuration file. The container fails to start up correctly because of missing certification files. I commented out the ssl server portion, rebuilt the image and executed the script again. Everything worked out just fine. After certificates were generated I just uncommented the ssl configuration, rebuilt the image and composed up the services.