How to Setup a Reverse Proxy With Let's Encrypt SSL Certificates Using Docker
I think this is really important in practical docker battle field. 🙂
Let’s go for the docker-compose.yml first.
1version: '3'
2
3services:
4 nginx:
5 image: nginx:1.15-alpine
6 restart: unless-stopped
7 volumes:
8 - ./data/nginx:/etc/nginx/conf.d
9 - ./data/certbot/conf:/etc/letsencrypt
10 - ./data/certbot/www:/var/www/certbot
11 ports:
12 - "80:80"
13 - "443:443"
14 command: "/bin/sh -c 'while :; do sleep 6h & wait $${!}; nginx -s reload; done & nginx -g \"daemon off;\"'"
15 certbot:
16 image: certbot/certbot
17 restart: unless-stopped
18 volumes:
19 - ./data/certbot/conf:/etc/letsencrypt
20 - ./data/certbot/www:/var/www/certbot
21 entrypoint: "/bin/sh -c 'trap exit TERM; while :; do certbot renew; sleep 12h & wait $${!}; done;'"
In order to get Let’s Encrypt SSL certificates, create a shell script file (init_letsencrypt.sh) like so:
1#!/bin/bash
2
3if ! [ -x "$(command -v docker-compose)" ]; then
4 echo 'Error: docker-compose is not installed.' >&2
5 exit 1
6fi
7
8domains=(domain.com www.domain.com)
9rsa_key_size=4096
10data_path="./data/certbot"
11email="" # Adding a valid address is strongly recommended
12staging=0 # Set to 1 if you're testing your setup to avoid hitting request limits
13
14if [ -d "$data_path" ]; then
15 read -p "Existing data found for $domains. Continue and replace existing certificate? (y/N) " decision
16 if [ "$decision" != "Y" ] && [ "$decision" != "y" ]; then
17 exit
18 fi
19fi
20
21if [ ! -e "$data_path/conf/options-ssl-nginx.conf" ] || [ ! -e "$data_path/conf/ssl-dhparams.pem" ]; then
22 echo "### Downloading recommended TLS parameters ..."
23 mkdir -p "$data_path/conf"
24 curl -s https://raw.githubusercontent.com/certbot/certbot/master/certbot-nginx/certbot_nginx/_internal/tls_configs/options-ssl-nginx.conf > "$data_path/conf/options-ssl-nginx.conf"
25 curl -s https://raw.githubusercontent.com/certbot/certbot/master/certbot/certbot/ssl-dhparams.pem > "$data_path/conf/ssl-dhparams.pem"
26 echo
27fi
28
29echo "### Creating dummy certificate for $domains ..."
30path="/etc/letsencrypt/live/$domains"
31mkdir -p "$data_path/conf/live/$domains"
32docker-compose run --rm --entrypoint "\
33 openssl req -x509 -nodes -newkey rsa:1024 -days 1\
34 -keyout '$path/privkey.pem' \
35 -out '$path/fullchain.pem' \
36 -subj '/CN=localhost'" certbot
37echo
38
39
40echo "### Starting nginx ..."
41docker-compose up --force-recreate -d nginx
42echo
43
44echo "### Deleting dummy certificate for $domains ..."
45docker-compose run --rm --entrypoint "\
46 rm -Rf /etc/letsencrypt/live/$domains && \
47 rm -Rf /etc/letsencrypt/archive/$domains && \
48 rm -Rf /etc/letsencrypt/renewal/$domains.conf" certbot
49echo
50
51echo "### Requesting Let's Encrypt certificate for $domains ..."
52#Join $domains to -d args
53domain_args=""
54for domain in "${domains[@]}"; do
55 domain_args="$domain_args -d $domain"
56done
57
58# Select appropriate email arg
59case "$email" in
60 "") email_arg="--register-unsafely-without-email" ;;
61 *) email_arg="--email $email" ;;
62esac
63
64# Enable staging mode if needed
65if [ $staging != "0" ]; then staging_arg="--staging"; fi
66
67docker-compose run --rm --entrypoint "\
68 certbot certonly --webroot -w /var/www/certbot \
69 $staging_arg \
70 $email_arg \
71 $domain_args \
72 --rsa-key-size $rsa_key_size \
73 --agree-tos \
74 --force-renewal" certbot
75echo
76
77echo "### Reloading nginx ..."
78docker-compose exec nginx nginx -s reload
As you can see in the docker-compose.yml file, you need a nginx config file in data/nginx/app.conf
1server {
2 listen 80;
3 server_name domain.com;
4 server_tokens off;
5
6 location /.well-known/acme-challenge/ {
7 root /var/www/certbot;
8 }
9
10 location / {
11 return 301 https://$host$request_uri;
12 }
13}
14
15server {
16 listen 443 ssl;
17 server_name domain.com;
18 server_tokens off;
19
20 ssl_certificate /etc/letsencrypt/live/domain.com/fullchain.pem;
21 ssl_certificate_key /etc/letsencrypt/live/domain.com/privkey.pem;
22 include /etc/letsencrypt/options-ssl-nginx.conf;
23 ssl_dhparam /etc/letsencrypt/ssl-dhparams.pem;
24
25 location / {
26 proxy_pass http://server_ip(for example, localhost):app_port;
27 proxy_set_header Host $http_host;
28 proxy_set_header X-Real-IP $remote_addr;
29 proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
30 proxy_set_header X-Forwarded-Proto $scheme;
31 }
32}
All set to start proxy server. Run the init_letsencrypt.sh first, and then as you may know,
1docker-compose up -d
Boom! Your service is now secured by Let's Encrypt SSL/TLS certificates.
Happy dockerizing, Gents! 🙂
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