Update Dockerfile

Dockerfile

@@ -1,4 +1,5 @@
-FROM debian:stable-slim
+# Use the specified Debian image
+FROM docker.io/library/debian:stable-slim@sha256:d10f0545d14bad5f4d230301f7e4fd904384f2dd16fda16d708f936c2fa1db3e
 
 # Install OpenVPN and Easy-RSA
 RUN apt-get update && \
@@ -6,11 +7,12 @@ RUN apt-get update && \
     rm -rf /var/lib/apt/lists/*
 
 # Set up configuration files and keys
-COPY ./openvpn-server.conf /etc/openvpn/server.conf
+COPY openvpn-server.conf /etc/openvpn/server.conf
 
 # Initialize Easy-RSA PKI
 RUN make-cadir /etc/openvpn/vars && \
     cd /etc/openvpn/vars && \
+    . ./vars && \
     ./clean-all && \
     ./build-ca --batch && \
     ./build-key-server --batch server && \