From 2ad85db016b341a97672c504b0188071429da44e Mon Sep 17 00:00:00 2001
From: Francis Santiago <francis.santiago@kaleidos.net>
Date: Tue, 19 May 2026 13:27:41 +0200
Subject: [PATCH] :whale: Fix frontend startup on hosts without IPv6 support

Signed-off-by: Francis Santiago <francis.santiago@kaleidos.net>
---
 docker/images/docker-compose.yaml       | 3 ++-
 docker/images/files/nginx-entrypoint.sh | 6 +++++-
 docker/images/files/nginx.conf.template | 2 +-
 3 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/docker/images/docker-compose.yaml b/docker/images/docker-compose.yaml
index 25d419a354..63f7a8cbbc 100644
--- a/docker/images/docker-compose.yaml
+++ b/docker/images/docker-compose.yaml
@@ -106,7 +106,8 @@ services:
 
     environment:
       << : [*penpot-flags, *penpot-http-body-size, *penpot-public-uri]
-
+      # Set to "true" on hosts where IPv6 is disabled at kernel boot level.
+      # PENPOT_DISABLE_IPV6_LISTEN: "true"
   penpot-backend:
     image: "penpotapp/backend:${PENPOT_VERSION:-2.15}"
     restart: always
diff --git a/docker/images/files/nginx-entrypoint.sh b/docker/images/files/nginx-entrypoint.sh
index e791ac64f0..2d4b5543de 100644
--- a/docker/images/files/nginx-entrypoint.sh
+++ b/docker/images/files/nginx-entrypoint.sh
@@ -37,7 +37,11 @@ export PENPOT_NITRATE_URI=${PENPOT_NITRATE_URI:-http://penpot-nitrate:3000}
 export PENPOT_MCP_URI=${PENPOT_MCP_URI:-http://penpot-mcp:4401}
 export PENPOT_MCP_URI_WS=${PENPOT_MCP_URI_WS:-http://penpot-mcp:4402}
 export PENPOT_HTTP_SERVER_MAX_BODY_SIZE=${PENPOT_HTTP_SERVER_MAX_BODY_SIZE:-367001600} # Default to 350MiB
-envsubst "\$PENPOT_BACKEND_URI,\$PENPOT_EXPORTER_URI,\$PENPOT_NITRATE_URI,\$PENPOT_MCP_URI,\$PENPOT_MCP_URI_WS,\$PENPOT_HTTP_SERVER_MAX_BODY_SIZE" \
+export PENPOT_IPV6_LISTEN_DIRECTIVE=${PENPOT_IPV6_LISTEN_DIRECTIVE:-"listen [::]:8080 default_server;"}
+if [ "${PENPOT_DISABLE_IPV6_LISTEN}" = "true" ]; then
+  export PENPOT_IPV6_LISTEN_DIRECTIVE=""
+fi
+envsubst "\$PENPOT_BACKEND_URI,\$PENPOT_EXPORTER_URI,\$PENPOT_NITRATE_URI,\$PENPOT_MCP_URI,\$PENPOT_MCP_URI_WS,\$PENPOT_HTTP_SERVER_MAX_BODY_SIZE,\$PENPOT_IPV6_LISTEN_DIRECTIVE" \
          < /tmp/nginx.conf.template > /etc/nginx/nginx.conf
 
 PENPOT_DEFAULT_INTERNAL_RESOLVER="$(awk 'BEGIN{ORS=" "} $1=="nameserver" { sub(/%.*$/,"",$2); print ($2 ~ ":")? "["$2"]": $2}' /etc/resolv.conf)"
diff --git a/docker/images/files/nginx.conf.template b/docker/images/files/nginx.conf.template
index c182856e6b..6efcbc47f3 100644
--- a/docker/images/files/nginx.conf.template
+++ b/docker/images/files/nginx.conf.template
@@ -73,7 +73,7 @@ http {
 
     server {
         listen 8080 default_server;
-        listen [::]:8080 default_server;
+        ${PENPOT_IPV6_LISTEN_DIRECTIVE}
         server_name _;
 
         client_max_body_size $PENPOT_HTTP_SERVER_MAX_BODY_SIZE;