update: Dockerfile - new vars include docker cli

- new: vars VPN_CT_NAME and VPN_IF_NAME, used while managing iptables rules for the listen port of qBittorrent
- new: include docker client binary in image to connect to vpn container

Dockerfile

@@ -1,9 +1,21 @@
+# syntax=docker/dockerfile:1
+
+FROM ubuntu:jammy AS docker-cli
+
+RUN apt update && \
+    apt install --no-install-suggests --no-install-recommends -y ca-certificates curl gnupg lsb-release
+RUN mkdir -m 0755 -p /etc/apt/keyrings && \
+    curl -fsSL https://download.docker.com/linux/ubuntu/gpg | gpg --dearmor -o /etc/apt/keyrings/docker.gpg && \
+    echo "deb [arch=$(dpkg --print-architecture) signed-by=/etc/apt/keyrings/docker.gpg] https://download.docker.com/linux/ubuntu $(lsb_release -cs) stable" | tee /etc/apt/sources.list.d/docker.list > /dev/null
+RUN apt update && \
+    apt install --no-install-suggests --no-install-recommends -y docker-ce-cli
+
 FROM ubuntu:jammy
 
 LABEL org.opencontainers.image.source="https://github.com/soxfor/qbittorrent-natmap"
 LABEL org.opencontainers.image.base.name="ubuntu:jammy"
 LABEL description="Map port via NAT-PMP and update qBittorrent configuration"
-LABEL version="1.0.0"
+LABEL version="1.0.2"
 
 ARG DEBIAN_FRONTEND=noninteractive
 
@@ -17,10 +29,14 @@ ENV QBITTORRENT_PORT='8080'
 ENV QBITTORRENT_USER='admin'
 ENV QBITTORRENT_PASS='adminadmin'
 ENV VPN_GATEWAY=''
+ENV VPN_CT_NAME='gluetun'
+ENV VPN_IF_NAME='tun0'
 ENV CHECK_INTERVAL='300'
 ENV NAT_LEASE_LIFETIME='300'
 
+COPY --from=docker-cli /usr/bin/docker /usr/bin/docker
 COPY data/start.sh /start.sh
+
 RUN chmod 750 /start.sh
 
 CMD ["./start.sh"]