A small docker image running stunnel

Base Docker Image

Debian Bullseye (x64)

Software

stunnel - A GPL licensed FTP server

Get the image from Docker Hub

docker pull fullaxx/stunnel-server

Networking Options

There are 2 environment variables that must be specified: ACCEPT and CONNECT
These values will go directly into your stunnel.conf file
ACCEPT will define the listening socket

-p 76.51.51.84:443:443 -e ACCEPT=443
--network=host -e ACCEPT=76.51.51.84:443

CONNECT will define the backend service connection

-e CONNECT=172.17.0.1:80

Certificate Options

There are 2 ways to provide certificate/key files to stunnel
In both cases the files must be provided in a volume called /crypto
You can provide a single key+certificate pem file:

-v /srv/docker/mydomain/mycerts:/crypto -e CERTKEYFILE=stunnel.pem

You can provide a certificate file along with a seperate key file:

-v /srv/docker/mydomain/mycerts:/crypto -e CERTFILE=stunnel.crt -e KEYFILE=stunnel.key

Logging Options

If you would like to see the stunnel logs on your host machine

-v /srv/docker/stunnel4/logs:/var/log/stunnel4

Run the image

Run the image listening on 76.51.51.84:443 and connecting to 172.17.0.1:80 using a single PEM file

docker run -d \
-p 76.51.51.84:443:443 -e ACCEPT=443 -e CONNECT=172.17.0.1:80 \
-v /srv/docker/mydomain/mycerts:/crypto -e CERTKEYFILE=stunnel.pem \
fullaxx/stunnel-server

Run the image listening on 76.51.51.84:443 and connecting to 172.17.0.1:80 using seperate PEM files

docker run -d \
-p 76.51.51.84:443:443 -e ACCEPT=443 -e CONNECT=172.17.0.1:80 \
-v /srv/docker/mydomain/mycerts:/crypto -e CERTFILE=stunnel.crt -e KEYFILE=stunnel.key \
fullaxx/stunnel-server

Run the image with host networking

docker run -d \
--network=host -e ACCEPT=76.51.51.84:443 -e CONNECT=172.17.0.1:80 \
-v /crypto:/crypto -e CERTKEYFILE=certkey.pem \
fullaxx/stunnel-server

Create a self-signed certificate

For a quick example on SSL certificate creation, go here

Build it locally using the github repository

docker build -t="fullaxx/stunnel-server" github.com/Fullaxx/stunnel-server

Posting Issues on Github

When posting issues, please provide the following:

• docker run line used to create the container
• output from docker logs
• screenshot showing the issue if not described in logs
• any other relevant networking information