The simpliest solution to add SSL cert to your site
Docker image for automatic generation of SSL certs using Let's encrypt and Open Resty, with reasonable SSL settings, HTTP/2 and WebSockets support out-of-the-box.
You can specify allowed domains and simple proxies using ENV variables, and easily override nginx.conf
to your needs.
This is possible thanks to OpenResty and lua-resty-auto-ssl.
Image status: used in production. Some backward-compatible changes may be added in the future.
Quick start to generate and auto-renew certs for your blog / application:
# replace these values
export DOMAIN=yourdomain.com
export APP_ADDRESS=localhost:8080
# install docker first, and then run following command
docker run -d \
--name nginx-auto-ssl \
--restart on-failure \
--network host \
-e ALLOWED_DOMAINS="$DOMAIN" \
-e SITES="$DOMAIN=$APP_ADDRESS" \
-v ssl-data:/etc/resty-auto-ssl \
valian/docker-nginx-auto-ssl
# display logs from container, to check if everything is fine.
docker logs nginx-auto-ssl
Docker-compose example:
# docker-compose.yml
version: '2'
services:
nginx:
image: valian/docker-nginx-auto-ssl
restart: on-failure
ports:
- 80:80
- 443:443
volumes:
- ssl_data:/etc/resty-auto-ssl
environment:
ALLOWED_DOMAINS: 'yourdomain.com'
SITES: 'yourdomain.com=myapp:80'
# your application, listening on port specified in `SITES` env variable
myapp:
image: nginx
volumes:
ssl_data:
start using
docker-compose up -d
Both cases will work when request to yourdomain.com
will reach just-deployed nginx (so when it will be running on your server, with correctly defined DNS entry).
Available configuration options:
Variable | Example | Description |
---|---|---|
ALLOWED_DOMAINS | (www|api).example.com , example.com , ([a-z]+.)?example.com |
Regex pattern of allowed domains. Internally, we're using ngx.re.match. By default we accept all domains |
DIFFIE_HELLMAN | true |
Force regeneration of dhparam.pem . If not specified, default one is used. |
SITES | db.com=localhost:5432; *.app.com=localhost:8080 , _=localhost:8080 |
Shortcut for defining multiple proxies, in form of domain1=endpoint1; domain2=endpoint2 . Default template for proxy is here. Name _ means default server, just like in nginx configuration |
FORCE_HTTPS | true , false |
If true , automatically adds location to resty-server-http.conf redirecting traffic from http to https. true by default. |
LETSENCRYPT_URL | https://acme-v02.api.letsencrypt.org/directory , https://acme-staging-v02.api.letsencrypt.org/directory |
Let's Encrypt server URL to use |
RESOLVER_ADDRESS | 8.8.8.8 , 127.0.0.53 |
DNS resolver used for OCSP stapling. 8.8.8.8 by default. To disable ipv6 append ipv6=off , eg 8.8.8.8 ipv6=off |
STORAGE_ADAPTER | file , redis |
Location to store generated certificates. Best practice is redis in order to avoid I/O blocking in OpenResty and make the certs available across multiple containers (for a load balanced environment) . file by default |
REDIS_HOST | hostname , ip address |
The redis host name to use for cert storage. Required if STORAGE_ADAPTER=redis |
REDIS_PORT | port number |
The redis port number. 6379 by default |
REDIS_DB | db_number |
The Redis database number used by lua-resty-auto-ssl to save certificates. 0 by default |
REDIS_KEY_PREFIX | some-prefix |
Prefix all keys stored in Redis with this string. '' by default |
If you want to proxy multiple sites (probably the most common case, that's why I've made it possible to achieve without custom configuration):
docker run -d \
--name nginx-auto-ssl \
--restart on-failure \
-p 80:80 \
-p 443:443 \
-e ALLOWED_DOMAINS=example.com \
-e SITES='example.com=localhost:5432;*.example.com=localhost:8080' \
valian/docker-nginx-auto-ssl
Additional server blocks are automatically loaded from /etc/nginx/conf.d/*.conf
. If you want to provide your own configuration, you can either use volumes or create custom image.
Example server configuration (for example, named server.conf
)
server {
listen 443 ssl default_server;
# remember about this line!
include resty-server-https.conf;
location / {
proxy_pass http://app;
}
location /api {
proxy_pass http://api;
}
}
Volumes way
# instead of $PWD, use directory with your custom configurations
docker run -d \
--name nginx-auto-ssl \
--restart on-failure \
-p 80:80 \
-p 443:443 \
-v $PWD:/etc/nginx/conf.d
valian/docker-nginx-auto-ssl
Custom image way
FROM valian/docker-nginx-auto-ssl
# instead of . use directory with your configurations
COPY . /etc/nginx/conf.d
docker build -t docker-nginx-auto-ssl .
docker run [YOUR_OPTIONS] docker-nginx-auto-ssl
You have to override /usr/local/openresty/nginx/conf/server-proxy.conf
either using volume or custom image. Basic templating is implemented for variables $SERVER_NAME
and $SERVER_ENDPOINT
.
Example template:
server {
listen 443 ssl;
server_name $SERVER_NAME;
include resty-server-https.conf;
location / {
proxy_pass http://$SERVER_ENDPOINT;
}
}
If you have custom requirements and other customization options are not enough, you can easily provide your own configuration.
Example Dockerfile
:
FROM valian/docker-nginx-auto-ssl
COPY nginx.conf /usr/local/openresty/nginx/conf/
Minimal working nginx.conf
:
events {
worker_connections 1024;
}
http {
# required
include resty-http.conf;
server {
listen 443 ssl;
# required
include resty-server-https.conf;
# you should add your own locations here
}
server {
listen 80 default_server;
# required
include resty-server-http.conf;
}
}
Minimal nginx.conf
with support for $SITES
and conf.d
includes
events {
worker_connections 1024;
}
http {
include resty-http.conf;
server {
listen 80 default_server;
include resty-server-http.conf;
}
# you can insert your blocks here or inside conf.d
include /etc/nginx/conf.d/*.conf;
}
Build and run it using
docker build -t docker-nginx-auto-ssl .
docker run [YOUR_OPTIONS] docker-nginx-auto-ssl
A short walktrough of what's going on here.
- The docker entrypoint is responsible for preparing a location block for each site declared in
SITES
env variable. This file is used as a template. - when request comes to port 80, it's by default redirected to 443 (HTTP -> HTTPS redirection)
- when request comes to port 443, HTTPS certificate is resolved by lua code (relevant file in this repo and source code from lua-resty-auto-ssl). If certificate exists for a given domain and is valid, it's returned. Otherwise, a process of generating new certificate starts. It's initialized here and uses https://github.com/dehydrated-io/dehydrated for all the Let's Encrypt-related communication. It starts challenge process, prepares files for challenge and receives certificates. All of that is done in a couple of seconds, while the original request waits for the response.
- challenge files are prepared and served under
/.well-known/acme-challenge/
(relevant file from this repo and source code from lua-resty-auto-ssl)
There's more to it, eg locks across all workers to only generate one certificate for a domain at a time, upload of the certificate to shared storage if configured, checking if domain is whitelisted, communication with Let's Encrypt etc. All in all, it's fairly efficient and shouldn't add any noticeable overhead to nginx.
- 11-11-2019 - Added gzip support and dropped TLS 1.0 and 1.1 #33
- 18-04-2019 - Added WebSocket support #22
- 29-05-2017 - Fixed duplicate redirect location after container restart #2
- 19-12-2017 - Support for
$SITES
variable - 2-12-2017 - Dropped HSTS by default
- 25-11-2017 - Initial release
MIT