Why does Kong Gateway fail to start with “socket() [::]:8000 failed (97: Address family not supported by protocol)” when installed via Helm?
The official kong/kong Helm chart’s default listen values include an IPv6 [::] listener alongside the IPv4 0.0.0.0 one. If IPv6 is disabled in the Kubernetes cluster, NGINX can’t bind to it and Kong fails to start. Override the listen directives via the chart’s env: block (for example env.proxy_listen) to drop the [::] entries and bind IPv4 only.
I am trying to install Kong Gateway in my Kubernetes environment using Helm. When I install, I see the following error and Kong will not start:
nginx: [emerg] socket() [::]:8000 failed (97: Address family not supported by protocol)
nginx: configuration file /tmp/tmp.Wv0OvAzYBz/nginx.conf test failedThe official kong/kong Helm chart’s default KONG_PROXY_LISTEN (and KONG_ADMIN_LISTEN/KONG_STATUS_LISTEN) value includes an IPv6 [::] listener alongside the IPv4 0.0.0.0 one (confirmed still the case on the current chart, e.g. KONG_PROXY_LISTEN=0.0.0.0:8000, [::]:8000, 0.0.0.0:8443 http2 ssl, [::]:8443 http2 ssl). This is generally okay unless IPv6 is in some way disabled in your Kubernetes cluster. If NGINX is blocked from binding to an IPv6 address you will receive the above error.
The current chart no longer exposes an addresses: field on the Kubernetes Service blocks (proxy:, admin:, manager:, etc.) at all — that field does not exist anywhere in the chart’s values schema, and in any case a Kubernetes Service-level setting has no effect on which addresses the Kong/NGINX process itself binds to inside the container, which is what actually produces this error. The correct, current fix is to override the listen directives directly via the chart’s env: block, dropping the [::] IPv6 entries:
env:
proxy_listen: "0.0.0.0:8000, 0.0.0.0:8443 http2 ssl"
admin_listen: "127.0.0.1:8444 http2 ssl"
status_listen: "0.0.0.0:8100"Add only the listener overrides you actually need — proxy_listen is the one that matters for this exact error, since it targets port 8000. Confirmed via helm template against the current chart that setting env.proxy_listen correctly overrides the rendered KONG_PROXY_LISTEN environment variable to the IPv4-only value given.