Add README.md

Author: kitten

README.md

@@ -0,0 +1,70 @@
+# Strongswan on Docker
+
+Base docker image to run a Strongswan IPsec and a XL2TPD server.
+
+## Usage
+
+Run the following to start the container:
+
+```
+docker run -d -p 500:500/udp -p 4500:4500/udp -p 1701:1701/udp --privileged philplckthun/strongswan
+```
+
+If you haven't set any login credentials via configuration files or environment variables, then a new random password will be set. To get it, read the logs of the running container:
+
+```
+docker logs <CONTAINER>
+```
+
+Search for this line in the output at the top:
+
+```
+No VPN_PASSWORD set! Generated a random password: mrXEv2S3F
+No VPN_PSK set! Generated a random PSK key: NZESSabnC
+```
+
+Here, the user hasn't set a PSK secret and password.
+
+## Environment variables
+
+By default a single account is added for EAP and XAuth login.
+
+Its password is specified by the `VPN_PASSWORD` environment variable, and its username is specified by the `VPN_USER` variable.
+
+`VPN_USER` defaults to `user` and `VPN_PASSWORD` is randomised if not changed.
+
+The PSK (pre-shared key) is specified in the `VPN_PSK` environment variable, and is randomised as well.
+
+You can inject these variables through `docker run`:
+
+```
+docker run ... -e VPN_USER=dave VPN_PASSWORD=dave-is-awesome ...
+```
+
+## Volume / Configuration files
+
+There is a single volume that is mounted at `/etc/ipsec.d`. Through it you can add a lot of Strongswan configuration. Additionally you can overwrite:
+
+* /etc/ppp/l2tp-secrets
+* /etc/ipsec.secrets
+* /etc/ipsec.conf
+* /etc/strongswan.conf
+* /etc/xl2tpd.conf
+
+with it, by putting your configuration files in that volume folder as well. They will be copied to the correct locations.
+
+## Services running
+
+There are two services running: *Strongswan* and addtionally *XL2TPD* for IPSec/L2TP support.
+
+The default IPSec configuration supports:
+
+* IKEv2 with EAP Authentication (Though a certificate has to be added for that to work)
+* IKEv2 with PSK
+* IKEv1 with PSK and XAuth (Cisco IPSec)
+* IPSec/L2TP with PSK
+
+The ports that are exposed for this container to work are:
+
+* 4500/udp and 500/udp for IPSec 
+* 1701/udp for L2TP

run.sh

@@ -32,7 +32,7 @@ if [ "$VPN_PASSWORD" = "$VPN_PSK" ]; then
 	echo "It is not recommended to use the same secret as password and PSK key!"
 fi
 
-cat > /etc/ppp/chap-secrets <<EOF
+cat > /etc/ppp/l2tp-secrets <<EOF
 # This file holds secrets for L2TP authentication.
 # Username  Server  Secret  Hosts