add Dockerfile and notes

Dockerfile

@@ -0,0 +1,19 @@
+FROM debian:bullseye-20230208-slim
+
+WORKDIR /opt
+
+RUN apt update
+
+RUN apt install -y \
+    git autoconf automake pkg-config gcc g++ libssl-dev make ppp-dev pppoe
+
+COPY . ./
+
+
+RUN ./autogen.sh && \
+        ./configure --prefix=/usr/local --sysconfdir=/etc --disable-dependency-tracking && \
+    make && make install
+
+ENTRYPOINT ["/usr/local/bin/openfortivpn"]
+
+CMD ["-c", "/etc/openfortivpn/config"]

README.md

@@ -174,6 +174,25 @@ For other distros, you'll need to build and install from source:
 
     Finally, install runtime dependency `ppp` or `pppd`.
 
+Docker
+----------------
+
+Build
+
+```bash
+docker build . -t openforticlient
+```
+Run
+```bash
+docker run --privileged --cap-add=NET_ADMIN --net host -d -v config:/etc/openfortivpn/config openforticlient
+```
+
+or with parameters
+
+```bash
+docker run --privileged --cap-add=NET_ADMIN --net host -d -v config:/etc/openfortivpn/config openforticlient -c /etc/openfortivpn/config --set-dns=0 --pppd-use-peerdns=1
+```
+
 Running as root?
 ----------------