Fix/bind addr ipv6 fallback

README.md

@@ -118,6 +118,7 @@ services:
       - PROXY_DOMAIN=code-server.my.domain #optional
       - DEFAULT_WORKSPACE=/config/workspace #optional
       - PWA_APPNAME=code-server #optional
+      - BIND_ADDR="[::]:8443" #optional
     volumes:
       - /path/to/code-server/config:/config
     ports:
@@ -140,6 +141,7 @@ docker run -d \
   -e PROXY_DOMAIN=code-server.my.domain `#optional` \
   -e DEFAULT_WORKSPACE=/config/workspace `#optional` \
   -e PWA_APPNAME=code-server `#optional` \
+  -e BIND_ADDR="[::]:8443" #optional
   -p 8443:8443 \
   -v /path/to/code-server/config:/config \
   --restart unless-stopped \
@@ -163,6 +165,7 @@ Containers are configured using parameters passed at runtime (such as those abov
 | `-e PROXY_DOMAIN=code-server.my.domain` | If this optional variable is set, this domain will be proxied for subdomain proxying. See [Documentation](https://github.com/coder/code-server/blob/main/docs/guide.md#using-a-subdomain) |
 | `-e DEFAULT_WORKSPACE=/config/workspace` | If this optional variable is set, code-server will open this directory by default |
 | `-e PWA_APPNAME=code-server` | If this optional variable is set, the PWA app will the specified name. |
+| `-e BIND_ADDR=[::]:8443` | If this optional variable is set, code-server will listen to this address instead of auto-detecting. |
 | `-v /config` | Contains all relevant configuration files. |
 | `--read-only=true` | Run container with a read-only filesystem. Please [read the docs](https://docs.linuxserver.io/misc/read-only/). |
 | `--user=1000:1000` | Run container with a non-root user. Please [read the docs](https://docs.linuxserver.io/misc/non-root/). |
@@ -329,6 +332,7 @@ 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 +18,23 @@ if [[ -z ${PWA_APPNAME} ]]; then
     PWA_APPNAME="code-server"
 fi
 
+if [[ -z ${BIND_ADDR} ]] ; then
+    # 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
+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 \