nginx fails with IPv6 at Kubernetes cluster which is not supported IPv6

[MasayaAoyama]

we encountered following error messages with image swaggerapi/swagger-ui:v4.17.1.
I think an interface cannot support IPv6 at our kubernetes clusters.
affected issues: #8438 （cc: @Southclaws ）

So we would like to control enable/disable IPv6 with environment variable.

$ kubectl get pods | grep swagger
swagger-784d787cfc-f46sx                      0/1     Error                        5 (91s ago)    3m2s
swagger-784d787cfc-l4nqh                      0/1     CrashLoopBackOff             4 (80s ago)    3m3s


$ kubectl  logs -f swagger-784d787cfc-f46sx
/docker-entrypoint.sh: /docker-entrypoint.d/ is not empty, will attempt to perform configuration
/docker-entrypoint.sh: Looking for shell scripts in /docker-entrypoint.d/
/docker-entrypoint.sh: Launching /docker-entrypoint.d/10-listen-on-ipv6-by-default.sh
10-listen-on-ipv6-by-default.sh: info: ipv6 not available
/docker-entrypoint.sh: Launching /docker-entrypoint.d/20-envsubst-on-templates.sh
/docker-entrypoint.sh: Launching /docker-entrypoint.d/30-tune-worker-processes.sh
/docker-entrypoint.sh: Launching /docker-entrypoint.d/40-swagger-ui.sh
/docker-entrypoint.sh: Configuration complete; ready for start up
2023/03/06 21:22:32 [emerg] 1#1: socket() [::]:8080 failed (97: Address family not supported by protocol)
nginx: [emerg] socket() [::]:8080 failed (97: Address family not supported by protocol)

$ kubectl  exec -it mypod -- ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
2: tunl0@NONE: <NOARP> mtu 1480 qdisc noop state DOWN group default qlen 1000
    link/ipip 0.0.0.0 brd 0.0.0.0
4: eth0@if3761: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1480 qdisc noqueue state UP group default
    link/ether aa:0a:00:e4:e8:3f brd ff:ff:ff:ff:ff:ff link-netnsid 0
    inet 192.168.0.1/32 scope global eth0
       valid_lft forever preferred_lft forever

Q&A (please complete the following information)

• OS: [e.g. macOS]
• Browser: [e.g. chrome, safari]
• Version: [e.g. 22]
• Method of installation: [e.g. npm, dist assets]
• Swagger-UI version: [e.g. 3.10.0]
• Swagger/OpenAPI version: [e.g. Swagger 2.0, OpenAPI 3.0]

Content & configuration

Example Swagger/OpenAPI definition:

# your YAML here

Swagger-UI configuration options:

SwaggerUI({
  // your config options here
})

?yourQueryStringConfig

Describe the bug you're encountering

To reproduce...

Steps to reproduce the behavior:

1. Go to '...'
2. Click on '....'
3. Scroll down to '....'
4. See error

Expected behavior

Screenshots

Additional context or thoughts

[char0n]

@MasayaAoyama,

Thanks for the report. I've issued #8449. Please have a look at it.

[char0n]

Fix will be released in next release cycle. Closing.

[Southclaws]

Apologies for that one, I didn't consider environments that did not support ipv6! Thanks for the quick fix and the config value to support both of our use-cases 🙏

[MasayaAoyama]

Thank you for fix it🙏