fix custom-error-pages file not exist

[learn0208]

What this PR does / why we need it:

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation only

Which issue/s this PR fixes

HttpCode error, page not found.

How Has This Been Tested?

Checklist:

• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I've read the CONTRIBUTION guide
• I have added tests to cover my changes.
• All new and existing tests passed.

[k8s-ci-robot]

Thanks for your pull request. Before we can look at your pull request, you'll need to sign a Contributor License Agreement (CLA).

📝 Please follow instructions at https://git.k8s.io/community/CLA.md#the-contributor-license-agreement to sign the CLA.

It may take a couple minutes for the CLA signature to be fully registered; after that, please reply here with a new comment and we'll verify. Thanks.

---

• If you've already signed a CLA, it's possible we don't have your GitHub username or you're using a different email address. Check your existing CLA data and verify that your email is set on your git commits.
• If you signed the CLA as a corporation, please sign in with your organization's credentials at https://identity.linuxfoundation.org/projects/cncf to be authorized.
• If you have done the above and are still having issues with the CLA being reported as unsigned, please log a ticket with the Linux Foundation Helpdesk: https://support.linuxfoundation.org/
• Should you encounter any issues with the Linux Foundation Helpdesk, send a message to the backup e-mail support address at: login-issues@jira.linuxfoundation.org

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository. I understand the commands that are listed here.

[k8s-ci-robot]

@learn0208: This issue is currently awaiting triage.

If Ingress contributors determines this is a relevant issue, they will accept it by applying the triage/accepted label and provide further guidance.

The triage/accepted label can be added by org members by writing /triage accepted in a comment.

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.

[k8s-ci-robot]

Welcome @learn0208!

It looks like this is your first PR to kubernetes/ingress-nginx 🎉. Please refer to our pull request process documentation to help your PR have a smooth ride to approval.

You will be prompted by a bot to use commands during the review process. Do not be afraid to follow the prompts! It is okay to experiment. Here is the bot commands documentation.

You can also check if kubernetes/ingress-nginx has its own contribution guidelines.

You may want to refer to our testing guide if you run into trouble with your tests not passing.

If you are having difficulty getting your pull request seen, please follow the recommended escalation practices. Also, for tips and tricks in the contribution process you may want to read the Kubernetes contributor cheat sheet. We want to make sure your contribution gets all the attention it needs!

Thank you, and welcome to Kubernetes. 😃

[k8s-ci-robot]

Hi @learn0208. Thanks for your PR.

I'm waiting for a kubernetes member to verify that this patch is reasonable to test. If it is, they should reply with /ok-to-test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work. Regular contributors should join the org to skip this step.

Once the patch is verified, the new status will be reflected by the ok-to-test label.

I understand the commands that are listed here.

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.

[longwuyuan]

What is the issue number/link that this PR fixes ?
How can I reproduce the problem this PR fixes ?

[learn0208]

Thanks for your pull request. Before we can look at your pull request, you'll need to sign a Contributor License Agreement (CLA).

📝 Please follow instructions at https://git.k8s.io/community/CLA.md#the-contributor-license-agreement to sign the CLA.

It may take a couple minutes for the CLA signature to be fully registered; after that, please reply here with a new comment and we'll verify. Thanks.

• If you've already signed a CLA, it's possible we don't have your GitHub username or you're using a different email address. Check your existing CLA data and verify that your email is set on your git commits.
• If you signed the CLA as a corporation, please sign in with your organization's credentials at https://identity.linuxfoundation.org/projects/cncf to be authorized.
• If you have done the above and are still having issues with the CLA being reported as unsigned, please log a ticket with the Linux Foundation Helpdesk: https://support.linuxfoundation.org/
• Should you encounter any issues with the Linux Foundation Helpdesk, send a message to the backup e-mail support address at: login-issues@jira.linuxfoundation.org

Thanks for your pull request. Before we can look at your pull request, you'll need to sign a Contributor License Agreement (CLA).

📝 Please follow instructions at https://git.k8s.io/community/CLA.md#the-contributor-license-agreement to sign the CLA.

It may take a couple minutes for the CLA signature to be fully registered; after that, please reply here with a new comment and we'll verify. Thanks.

• If you've already signed a CLA, it's possible we don't have your GitHub username or you're using a different email address. Check your existing CLA data and verify that your email is set on your git commits.
• If you signed the CLA as a corporation, please sign in with your organization's credentials at https://identity.linuxfoundation.org/projects/cncf to be authorized.
• If you have done the above and are still having issues with the CLA being reported as unsigned, please log a ticket with the Linux Foundation Helpdesk: https://support.linuxfoundation.org/
• Should you encounter any issues with the Linux Foundation Helpdesk, send a message to the backup e-mail support address at: login-issues@jira.linuxfoundation.org

Completed

[learn0208]

What is the issue number/link that this PR fixes ? How can I reproduce the problem this PR fixes ?

# cd images/custom-error-pages/rootfs
# docker build -t defaultbackend:test .
# docker run --rm -p 808:8080  defaultbackend:test .
# curl -H "X-code: 404" 127.0.0.1:808

[longwuyuan]

@learn0208 it is very likely that you have a valid and reasonable information updated to this PR.
But, not everyone can understand and reproduce the problem you seem to be hinting at.
I would not want to follow this process as ad-hoc changes like this lack transparency of a issue with details and a step-by-step process to reproduce the problem on a K8s cluster with ingress objects and ingress rules.

Lets wait for other opinions but I myself do not approve of this PR in its current state.

[learn0208]

We wanted to customize the ingress-nginx error page reponse. Build default-http-backend image from github, but got back was '404 page not found'. So the Dockerfile can be improved, such as adding such a line

COPY --from=builder /go/src/k8s.io/ingress-nginx/images/custom-error-pages/www /www

Our test step.

# kubectl version
Client Version: version.Info{Major:"1", Minor:"15", GitVersion:"v1.15.4", GitCommit:"67d2fcf276fcd9cf743ad4be9a9ef5828adc082f", GitTreeState:"clean", BuildDate:"2019-09-18T14:51:13Z", GoVersion:"go1.12.9", Compiler:"gc", Platform:"linux/amd64"}
Server Version: version.Info{Major:"1", Minor:"15", GitVersion:"v1.15.4", GitCommit:"67d2fcf276fcd9cf743ad4be9a9ef5828adc082f", GitTreeState:"clean", BuildDate:"2019-09-18T14:41:55Z", GoVersion:"go1.12.9", Compiler:"gc", Platform:"linux/amd64"}

build from https://github.com/kubernetes/ingress-nginx/blob/main/images/custom-error-pages/rootfs/Dockerfile as defaultbackend:test.
default-http-backend config

apiVersion: extensions/v1beta1
kind: Deployment
metadata:
  name: default-http-backend
  labels:
    k8s-app: default-http-backend
  namespace: ingress-nginx
spec:
  replicas: 1
  template:
    metadata:
      labels:
        k8s-app: default-http-backend
    spec:
      terminationGracePeriodSeconds: 60
      containers:
      - name: default-http-backend
        # Any image is permissable as long as:
        # 1. It serves a 404 page at /
        # 2. It serves 200 on a /healthz endpoint
        image: defaultbackend:test
        livenessProbe:
          httpGet:
            path: /healthz
            port: 8080
            scheme: HTTP
          initialDelaySeconds: 30
          timeoutSeconds: 5
        ports:
        - containerPort: 8080
        resources:
          limits:
            cpu: 100m
            memory: 200Mi
          requests:
            cpu: 10m
            memory: 20Mi
---
apiVersion: v1
kind: Service
metadata:
  name: default-http-backend
  namespace: ingress-nginx
  labels:
    k8s-app: default-http-backend
spec:
  ports:
  - port: 80
    targetPort: 8080
  selector:
    k8s-app: default-http-backend

ingress-nginx information
version: 0.49.2
Host: 175.63.100.112
run args

          ...
          args:
            - /nginx-ingress-controller
            - --default-backend-service=$(POD_NAMESPACE)/default-http-backend
            - --publish-service=$(POD_NAMESPACE)/ingress-nginx-controller
            - --election-id=ingress-controller-leader
            - --ingress-class=nginx
            - --configmap=$(POD_NAMESPACE)/ingress-nginx-controller
          ...

# curl 175.63.100.112
404 page not found

get default-http-backend pod log

2021/09/29 09:16:18 format not specified. Using text/html
2021/09/29 09:16:18 unexpected error reading return code: strconv.Atoi: parsing "": invalid syntax. Using 404
2021/09/29 09:16:18 unexpected error opening file: open /www/404.html: no such file or directory
2021/09/29 09:16:18 unexpected error opening file: open /www/4xx.html: no such file or directory
2021/09/29 09:16:18 http: superfluous response.WriteHeader call from main.errorHandler.func1 (main.go:164)

rebuild docker image from https://github.com/learn0208/ingress-nginx/blob/main/images/custom-error-pages/rootfs/Dockerfile as defaultbackend:bugfix

# kubectl set image deployment/default-http-backend default-http-backend:defaultbackend:bugfix
# curl 175.63.100.112
<span>The page you're looking for could not be found.</span>

[longwuyuan]

The change is text in response. In my opinion this is not a improvement for most use cases or most users. Also since users can change attributes like image, there is no compelling reason to approve this PR.

[learn0208]

The change is text in response. In my opinion this is not a improvement for most use cases or most users. Also since users can change attributes like image, there is no compelling reason to approve this PR.

add images

[mrksngl]

@longwuyuan maybe I got you wrong here, but no, it's not just a change in the response text.

Thing is, that the docker image (without PR) misses the www directory. Then, when it's used as default backend (and wll, that's its purpose) and shall serve a customized 404 page (i.e. /www/404.html), it cannot find that file and replies a generic "404 Page not found" response instead.

The PR just copies the provided www directory into the image. I think users would more likely expect getting the /www/404.html instead of that file being totally absent, leading to an error.

But that is not even all: the PR is incomplete (this also goes to @learn0208):
There is also a etc/mime.types and this file should also be provided in the container.
It is needed to map the original Accept header (which is passed to the default backend as X-Format by ingress) to a file extension.
If it's missing, the program will fall back to .html for any format.

[rikatz]

/ok-to-test

[rikatz]

cycling back to this.

I understand the need but do we, in any case in nginx.tmpl refer to the /www as the custom error pages? (checking here, but let me know if you already know the answer)

[rikatz]

/lgtm
/approve
Thanks!

We are clearly missing those files inside custom-errors containers.

We should probably bump now the image to a new version and promote it, feel free to ping us on #ingress-nginx-dev in Slack (me, @strongjz , @longwuyuan, etc) to know how to proceed next.

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: learn0208, rikatz

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Needs approval from an approver in each of these files:

• images/OWNERS [rikatz]

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

[rikatz]

#15 pushing manifest for gcr.io/k8s-staging-ingress-nginx/nginx-errors:v20211223-helm-chart-4.0.13-19-g8e9bf7f62@sha256:1d69f28d6412b0f2a6302f9df9a6bc49e83703336a35f95ab109cad10e039120 is the manifest of this one and needs promotion

[mrksngl]

Still misses /etc/mime.types, needed for https://github.com/kubernetes/ingress-nginx/blob/main/images/custom-error-pages/rootfs/main.go#L129 to work.

[rikatz]

Can you add it via a new PR? Thanks!

[lucasfcnunes]

@rikatz @mrksngl

Can you add it via a new PR? Thanks!

Doing it at #10310

[mrksngl]

Oh I completely missed that request, thanks @lucasfcnunes for taking on.