build sslh with libproxyprotocol

Dockerfile

@@ -3,8 +3,7 @@ ARG TARGET_ARCH="library"
 
 FROM docker.io/${TARGET_ARCH}/alpine:${ALPINE_VERSION} AS build
 
-WORKDIR /sslh
-
+# Install build dependencies for sslh and libproxyprotocol
 RUN apk add --no-cache \
         'gcc' \
         'libconfig-dev' \
@@ -12,15 +11,39 @@ RUN apk add --no-cache \
         'musl-dev' \
         'pcre2-dev' \
         'perl' \
+        'git' \
+        'autoconf' \
+        'automake' \
+        'libtool' \
         ;
 
+# Build libproxyprotocol
+WORKDIR /tmp
+RUN git clone https://github.com/kosmas-valianos/libproxyprotocol.git && \
+    cd libproxyprotocol && \
+    make && \
+    mkdir -p /usr/local/include/ && \
+    mv libs/libproxyprotocol.so /usr/local/lib/ && \
+    mv src/* /usr/local/include/
+
+# Set environment variables for sslh to find libproxyprotocol
+ENV C_INCLUDE_PATH=/usr/local/include
+ENV LIBRARY_PATH=/usr/local/lib
+ENV LD_LIBRARY_PATH=/usr/local/lib
+
+WORKDIR /sslh
 COPY . /sslh
 
+# Configure and build sslh
+# The configure script should automatically detect libproxyprotocol
 RUN ./configure && make sslh-select && strip sslh-select
 
 FROM docker.io/${TARGET_ARCH}/alpine:${ALPINE_VERSION}
 
+# Copy libproxyprotocol.so from the build stage
+COPY --from=build /usr/local/lib/libproxyprotocol.so* /usr/local/lib/
 COPY --from=build "/sslh/sslh-select" "/usr/local/bin/sslh"
+
 RUN apk add --no-cache \
         'libconfig' \
         'pcre2' \
@@ -35,4 +58,4 @@ COPY "./container-entrypoint.sh" "/init"
 ENTRYPOINT [ "/init" ]
 
 # required for updating iptables
-USER root:root
+USER root:root