From c2fdda517575986115aff9a2b5bdfaac2da8039a Mon Sep 17 00:00:00 2001
From: salty <salty@salty.dk>
Date: Wed, 13 Dec 2023 17:03:35 +0100
Subject: [PATCH] add config templating

---
 Dockerfile           |  6 +++++-
 docker-entrypoint.sh | 36 ++++++++++++++++++++++++++++++++++++
 haproxy.cfg          |  2 +-
 3 files changed, 42 insertions(+), 2 deletions(-)
 create mode 100755 docker-entrypoint.sh

diff --git a/Dockerfile b/Dockerfile
index afdc46f..422a418 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -30,4 +30,8 @@ ENV ALLOW_RESTARTS=0 \
     TASKS=0 \
     VERSION=1 \
     VOLUMES=0
-COPY haproxy.cfg /usr/local/etc/haproxy/haproxy.cfg
+RUN apk add --no-cache gettext
+COPY docker-entrypoint.sh /
+COPY haproxy.cfg /usr/local/etc/haproxy/haproxy.cfg.template
+
+ENTRYPOINT ["/docker-entrypoint.sh"]
diff --git a/docker-entrypoint.sh b/docker-entrypoint.sh
new file mode 100755
index 0000000..32be970
--- /dev/null
+++ b/docker-entrypoint.sh
@@ -0,0 +1,36 @@
+#!/bin/sh
+set -e
+
+# Normalize the input for ENABLE_IPV6 to lowercase
+ENABLE_IPV6_LOWER=$(echo "$ENABLE_IPV6" | tr '[:upper:]' '[:lower:]')
+
+# Check for different representations of 'true' and set BIND_CONFIG
+case "$ENABLE_IPV6_LOWER" in
+    1|true|yes)
+        BIND_CONFIG="[::]:2375 v4v6"
+        ;;
+    *)
+        BIND_CONFIG=":2375"
+        ;;
+esac
+
+# Export BIND_CONFIG for envsubst
+export BIND_CONFIG
+
+# Process the HAProxy configuration template
+envsubst < /usr/local/etc/haproxy/haproxy.cfg.template > /usr/local/etc/haproxy/haproxy.cfg
+cat /usr/local/etc/haproxy/haproxy.cfg
+
+# Command-line argument handling
+if [ "${1#-}" != "$1" ]; then
+    set -- haproxy "$@"
+fi
+
+if [ "$#" -eq 0 ] || [ "$1" = 'haproxy' ]; then
+    if [ "$1" = 'haproxy' ]; then
+        shift
+    fi
+    set -- haproxy -W -db -f /usr/local/etc/haproxy/haproxy.cfg "$@"
+fi
+
+exec "$@"
diff --git a/haproxy.cfg b/haproxy.cfg
index c87c8d8..43e3526 100644
--- a/haproxy.cfg
+++ b/haproxy.cfg
@@ -44,7 +44,7 @@ backend docker-events
     timeout server 0
 
 frontend dockerfrontend
-    bind :::2375 v4v6
+    bind ${BIND_CONFIG}
     http-request deny unless METH_GET || { env(POST) -m bool }
     http-request allow if { path,url_dec -m reg -i ^(/v[\d\.]+)?/containers/[a-zA-Z0-9_.-]+/((stop)|(restart)|(kill)) } { env(ALLOW_RESTARTS) -m bool }
     http-request allow if { path,url_dec -m reg -i ^(/v[\d\.]+)?/containers/[a-zA-Z0-9_.-]+/start } { env(ALLOW_START) -m bool }