Fix/bind addr ipv6 fallback

README.md

@@ -329,6 +329,7 @@ Once registered you can define the dockerfile to use with `-f Dockerfile.aarch64
 
 ## Versions
 
+* **06.07.26:** - Fall back to ipv4 bind address when ipv6 is disabled in the kernel.
 * **17.05.26:** - Let server listen on both ipv4 and ipv6 even when running container as root.
 * **10.08.25:** - Let server listen on both ipv4 and ipv6.
 * **03.06.25:** - Allow setting PWA name using env var `PWA_APPNAME`.

readme-vars.yml

@@ -102,6 +102,7 @@ init_diagram: |
   "code-server:latest" <- Base Images
 # changelog
 changelogs:
+  - {date: "06.07.26:", desc: "Fall back to ipv4 bind address when ipv6 is disabled in the kernel."}
   - {date: "17.05.26:", desc: "Let server listen on both ipv4 and ipv6 even when running container as root."}
   - {date: "10.08.25:", desc: "Let server listen on both ipv4 and ipv6."}
   - {date: "03.06.25:", desc: "Allow setting PWA name using env var `PWA_APPNAME`."}

root/etc/s6-overlay/s6-rc.d/svc-code-server/run

@@ -18,12 +18,21 @@ if [[ -z ${PWA_APPNAME} ]]; then
     PWA_APPNAME="code-server"
 fi
 
+# Bind to the IPv6 wildcard (dual-stack, also serves IPv4) when IPv6 is
+# available, otherwise fall back to the IPv4 wildcard. Binding to "[::]"
+# fails outright on hosts/containers where IPv6 is disabled.
+if [[ -e /proc/net/if_inet6 ]]; then
+    BIND_ADDR="[::]:8443"
+else
+    BIND_ADDR="0.0.0.0:8443"
+fi
+
 if [[ -z ${LSIO_NON_ROOT_USER} ]]; then
     exec \
         s6-notifyoncheck -d -n 300 -w 1000 -c "nc -z 127.0.0.1 8443" \
             s6-setuidgid abc \
                 /app/code-server/bin/code-server \
-                    --bind-addr "[::]:8443" \
+                    --bind-addr "${BIND_ADDR}" \
                     --user-data-dir /config/data \
                     --extensions-dir /config/extensions \
                     --disable-telemetry \